diff --git a/codegen/sdk-codegen/aws-models/dynamodb.json b/codegen/sdk-codegen/aws-models/dynamodb.json
index 9cc85efde2c..c1bec4a26b1 100644
--- a/codegen/sdk-codegen/aws-models/dynamodb.json
+++ b/codegen/sdk-codegen/aws-models/dynamodb.json
@@ -1208,7 +1208,7 @@
             "traits": {
                 "smithy.api#length": {
                     "min": 1,
-                    "max": 25
+                    "max": 100
                 }
             }
         },
@@ -5147,7 +5147,7 @@
             "traits": {
                 "smithy.api#length": {
                     "min": 1,
-                    "max": 25
+                    "max": 100
                 }
             }
         },
@@ -6095,7 +6095,7 @@
             "traits": {
                 "smithy.api#length": {
                     "min": 1,
-                    "max": 25
+                    "max": 100
                 }
             }
         },
@@ -8924,7 +8924,7 @@
             "traits": {
                 "smithy.api#length": {
                     "min": 1,
-                    "max": 25
+                    "max": 100
                 }
             }
         },
@@ -8960,7 +8960,7 @@
                 "aws.api#clientDiscoveredEndpoint": {
                     "required": false
                 },
-                "smithy.api#documentation": "<p>\n            <code>TransactGetItems</code> is a synchronous operation that atomically retrieves\n            multiple items from one or more tables (but not from indexes) in a single account and\n            Region. A <code>TransactGetItems</code> call can contain up to 25\n                <code>TransactGetItem</code> objects, each of which contains a <code>Get</code>\n            structure that specifies an item to retrieve from a table in the account and Region. A\n            call to <code>TransactGetItems</code> cannot retrieve items from tables in more than one\n                Amazon Web Services account or Region. The aggregate size of the items in the\n            transaction cannot exceed 4 MB.</p>\n        <p>DynamoDB rejects the entire <code>TransactGetItems</code> request if any of\n            the following is true:</p>\n        <ul>\n            <li>\n                <p>A conflicting operation is in the process of updating an item to be\n                    read.</p>\n            </li>\n            <li>\n                <p>There is insufficient provisioned capacity for the transaction to be\n                    completed.</p>\n            </li>\n            <li>\n                <p>There is a user error, such as an invalid data format.</p>\n            </li>\n            <li>\n                <p>The aggregate size of the items in the transaction cannot exceed 4 MB.</p>\n            </li>\n         </ul>"
+                "smithy.api#documentation": "<p>\n            <code>TransactGetItems</code> is a synchronous operation that atomically retrieves\n            multiple items from one or more tables (but not from indexes) in a single account and\n            Region. A <code>TransactGetItems</code> call can contain up to 100\n                <code>TransactGetItem</code> objects, each of which contains a <code>Get</code>\n            structure that specifies an item to retrieve from a table in the account and Region. A\n            call to <code>TransactGetItems</code> cannot retrieve items from tables in more than one\n                Amazon Web Services account or Region. The aggregate size of the items in the\n            transaction cannot exceed 4 MB.</p>\n        <p>DynamoDB rejects the entire <code>TransactGetItems</code> request if any of\n            the following is true:</p>\n        <ul>\n            <li>\n                <p>A conflicting operation is in the process of updating an item to be\n                    read.</p>\n            </li>\n            <li>\n                <p>There is insufficient provisioned capacity for the transaction to be\n                    completed.</p>\n            </li>\n            <li>\n                <p>There is a user error, such as an invalid data format.</p>\n            </li>\n            <li>\n                <p>The aggregate size of the items in the transaction cannot exceed 4 MB.</p>\n            </li>\n         </ul>"
             }
         },
         "com.amazonaws.dynamodb#TransactGetItemsInput": {
@@ -8969,7 +8969,7 @@
                 "TransactItems": {
                     "target": "com.amazonaws.dynamodb#TransactGetItemList",
                     "traits": {
-                        "smithy.api#documentation": "<p>An ordered array of up to 25 <code>TransactGetItem</code> objects, each of which\n            contains a <code>Get</code> structure.</p>",
+                        "smithy.api#documentation": "<p>An ordered array of up to 100 <code>TransactGetItem</code> objects, each of which\n            contains a <code>Get</code> structure.</p>",
                         "smithy.api#required": {}
                     }
                 },
@@ -8993,7 +8993,7 @@
                 "Responses": {
                     "target": "com.amazonaws.dynamodb#ItemResponseList",
                     "traits": {
-                        "smithy.api#documentation": "<p>An ordered array of up to 25 <code>ItemResponse</code> objects, each of which\n            corresponds to the <code>TransactGetItem</code> object in the same position in the\n                <i>TransactItems</i> array. Each <code>ItemResponse</code> object\n            contains a Map of the name-value pairs that are the projected attributes of the\n            requested item.</p>\n        <p>If a requested item could not be retrieved, the corresponding\n                <code>ItemResponse</code> object is Null, or if the requested item has no projected\n            attributes, the corresponding <code>ItemResponse</code> object is an empty Map. </p>"
+                        "smithy.api#documentation": "<p>An ordered array of up to 100 <code>ItemResponse</code> objects, each of which\n            corresponds to the <code>TransactGetItem</code> object in the same position in the\n                <i>TransactItems</i> array. Each <code>ItemResponse</code> object\n            contains a Map of the name-value pairs that are the projected attributes of the\n            requested item.</p>\n        <p>If a requested item could not be retrieved, the corresponding\n                <code>ItemResponse</code> object is Null, or if the requested item has no projected\n            attributes, the corresponding <code>ItemResponse</code> object is an empty Map. </p>"
                     }
                 }
             }
@@ -9038,7 +9038,7 @@
             "traits": {
                 "smithy.api#length": {
                     "min": 1,
-                    "max": 25
+                    "max": 100
                 }
             }
         },
@@ -9080,7 +9080,7 @@
                 "aws.api#clientDiscoveredEndpoint": {
                     "required": false
                 },
-                "smithy.api#documentation": "<p>\n            <code>TransactWriteItems</code> is a synchronous write operation that groups up to 25\n            action requests. These actions can target items in different tables, but not in\n            different Amazon Web Services accounts or Regions, and no two actions can target the same\n            item. For example, you cannot both <code>ConditionCheck</code> and <code>Update</code>\n            the same item. The aggregate size of the items in the transaction cannot exceed 4\n            MB.</p>\n\n        <p>The actions are completed atomically so that either all of them succeed, or all of\n            them fail. They are defined by the following objects:</p>\n\n        <ul>\n            <li>\n                <p>\n                  <code>Put</code>  —   Initiates a <code>PutItem</code>\n                    operation to write a new item. This structure specifies the primary key of the\n                    item to be written, the name of the table to write it in, an optional condition\n                    expression that must be satisfied for the write to succeed, a list of the item's\n                    attributes, and a field indicating whether to retrieve the item's attributes if\n                    the condition is not met.</p>\n            </li>\n            <li>\n                <p>\n                  <code>Update</code>  —   Initiates an <code>UpdateItem</code>\n                    operation to update an existing item. This structure specifies the primary key\n                    of the item to be updated, the name of the table where it resides, an optional\n                    condition expression that must be satisfied for the update to succeed, an\n                    expression that defines one or more attributes to be updated, and a field\n                    indicating whether to retrieve the item's attributes if the condition is not\n                    met.</p>\n            </li>\n            <li>\n                <p>\n                  <code>Delete</code>  —   Initiates a <code>DeleteItem</code>\n                    operation to delete an existing item. This structure specifies the primary key\n                    of the item to be deleted, the name of the table where it resides, an optional\n                    condition expression that must be satisfied for the deletion to succeed, and a\n                    field indicating whether to retrieve the item's attributes if the condition is\n                    not met.</p>\n            </li>\n            <li>\n                <p>\n                  <code>ConditionCheck</code>  —   Applies a condition to an item\n                    that is not being modified by the transaction. This structure specifies the\n                    primary key of the item to be checked, the name of the table where it resides, a\n                    condition expression that must be satisfied for the transaction to succeed, and\n                    a field indicating whether to retrieve the item's attributes if the condition is\n                    not met.</p>\n            </li>\n         </ul>\n\n        <p>DynamoDB rejects the entire <code>TransactWriteItems</code> request if any of the\n            following is true:</p>\n        <ul>\n            <li>\n                <p>A condition in one of the condition expressions is not met.</p>\n            </li>\n            <li>\n                <p>An ongoing operation is in the process of updating the same item.</p>\n            </li>\n            <li>\n                <p>There is insufficient provisioned capacity for the transaction to be\n                    completed.</p>\n            </li>\n            <li>\n                <p>An item size becomes too large (bigger than 400 KB), a local secondary index\n                    (LSI) becomes too large, or a similar validation error occurs because of changes\n                    made by the transaction.</p>\n            </li>\n            <li>\n                <p>The aggregate size of the items in the transaction exceeds 4 MB.</p>\n            </li>\n            <li>\n                <p>There is a user error, such as an invalid data format.</p>\n            </li>\n         </ul>"
+                "smithy.api#documentation": "<p>\n            <code>TransactWriteItems</code> is a synchronous write operation that groups up to 100\n            action requests. These actions can target items in different tables, but not in\n            different Amazon Web Services accounts or Regions, and no two actions can target the same\n            item. For example, you cannot both <code>ConditionCheck</code> and <code>Update</code>\n            the same item. The aggregate size of the items in the transaction cannot exceed 4\n            MB.</p>\n\n        <p>The actions are completed atomically so that either all of them succeed, or all of\n            them fail. They are defined by the following objects:</p>\n\n        <ul>\n            <li>\n                <p>\n                  <code>Put</code>  —   Initiates a <code>PutItem</code>\n                    operation to write a new item. This structure specifies the primary key of the\n                    item to be written, the name of the table to write it in, an optional condition\n                    expression that must be satisfied for the write to succeed, a list of the item's\n                    attributes, and a field indicating whether to retrieve the item's attributes if\n                    the condition is not met.</p>\n            </li>\n            <li>\n                <p>\n                  <code>Update</code>  —   Initiates an <code>UpdateItem</code>\n                    operation to update an existing item. This structure specifies the primary key\n                    of the item to be updated, the name of the table where it resides, an optional\n                    condition expression that must be satisfied for the update to succeed, an\n                    expression that defines one or more attributes to be updated, and a field\n                    indicating whether to retrieve the item's attributes if the condition is not\n                    met.</p>\n            </li>\n            <li>\n                <p>\n                  <code>Delete</code>  —   Initiates a <code>DeleteItem</code>\n                    operation to delete an existing item. This structure specifies the primary key\n                    of the item to be deleted, the name of the table where it resides, an optional\n                    condition expression that must be satisfied for the deletion to succeed, and a\n                    field indicating whether to retrieve the item's attributes if the condition is\n                    not met.</p>\n            </li>\n            <li>\n                <p>\n                  <code>ConditionCheck</code>  —   Applies a condition to an item\n                    that is not being modified by the transaction. This structure specifies the\n                    primary key of the item to be checked, the name of the table where it resides, a\n                    condition expression that must be satisfied for the transaction to succeed, and\n                    a field indicating whether to retrieve the item's attributes if the condition is\n                    not met.</p>\n            </li>\n         </ul>\n\n        <p>DynamoDB rejects the entire <code>TransactWriteItems</code> request if any of the\n            following is true:</p>\n        <ul>\n            <li>\n                <p>A condition in one of the condition expressions is not met.</p>\n            </li>\n            <li>\n                <p>An ongoing operation is in the process of updating the same item.</p>\n            </li>\n            <li>\n                <p>There is insufficient provisioned capacity for the transaction to be\n                    completed.</p>\n            </li>\n            <li>\n                <p>An item size becomes too large (bigger than 400 KB), a local secondary index\n                    (LSI) becomes too large, or a similar validation error occurs because of changes\n                    made by the transaction.</p>\n            </li>\n            <li>\n                <p>The aggregate size of the items in the transaction exceeds 4 MB.</p>\n            </li>\n            <li>\n                <p>There is a user error, such as an invalid data format.</p>\n            </li>\n         </ul>"
             }
         },
         "com.amazonaws.dynamodb#TransactWriteItemsInput": {
@@ -9089,7 +9089,7 @@
                 "TransactItems": {
                     "target": "com.amazonaws.dynamodb#TransactWriteItemList",
                     "traits": {
-                        "smithy.api#documentation": "<p>An ordered array of up to 25 <code>TransactWriteItem</code> objects, each of which\n            contains a <code>ConditionCheck</code>, <code>Put</code>, <code>Update</code>, or\n                <code>Delete</code> object. These can operate on items in different tables, but the\n            tables must reside in the same Amazon Web Services account and Region, and no two of them\n            can operate on the same item. </p>",
+                        "smithy.api#documentation": "<p>An ordered array of up to 100 <code>TransactWriteItem</code> objects, each of which\n            contains a <code>ConditionCheck</code>, <code>Put</code>, <code>Update</code>, or\n                <code>Delete</code> object. These can operate on items in different tables, but the\n            tables must reside in the same Amazon Web Services account and Region, and no two of them\n            can operate on the same item. </p>",
                         "smithy.api#required": {}
                     }
                 },
diff --git a/codegen/sdk-codegen/aws-models/ec2.json b/codegen/sdk-codegen/aws-models/ec2.json
index 4a65b80587b..4fc4b293e86 100644
--- a/codegen/sdk-codegen/aws-models/ec2.json
+++ b/codegen/sdk-codegen/aws-models/ec2.json
@@ -1,5 +1,5 @@
 {
-    "smithy": "1.0",
+    "smithy": "2.0",
     "metadata": {
         "suppressions": [
             {
@@ -36,6 +36,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Min",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum number of accelerators. If this parameter is not specified, there is no minimum\n         limit.</p>",
                         "smithy.api#xmlName": "min"
                     }
@@ -44,6 +46,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Max",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of accelerators. If this parameter is not specified, there is no\n         maximum limit.</p>",
                         "smithy.api#xmlName": "max"
                     }
@@ -59,12 +63,16 @@
                 "Min": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum number of accelerators. To specify no minimum limit, omit this\n         parameter.</p>"
                     }
                 },
                 "Max": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of accelerators. To specify no maximum limit, omit this\n         parameter. To exclude accelerator-enabled instance types, set <code>Max</code> to\n         <code>0</code>.</p>"
                     }
                 }
@@ -74,26 +82,32 @@
             }
         },
         "com.amazonaws.ec2#AcceleratorManufacturer": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "nvidia",
-                        "name": "NVIDIA"
-                    },
-                    {
-                        "value": "amd",
-                        "name": "AMD"
-                    },
-                    {
-                        "value": "amazon-web-services",
-                        "name": "AMAZON_WEB_SERVICES"
-                    },
-                    {
-                        "value": "xilinx",
-                        "name": "XILINX"
+            "type": "enum",
+            "members": {
+                "NVIDIA": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "nvidia"
                     }
-                ]
+                },
+                "AMD": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "amd"
+                    }
+                },
+                "AMAZON_WEB_SERVICES": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "amazon-web-services"
+                    }
+                },
+                "XILINX": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "xilinx"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AcceleratorManufacturerSet": {
@@ -106,46 +120,62 @@
             }
         },
         "com.amazonaws.ec2#AcceleratorName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "a100",
-                        "name": "A100"
-                    },
-                    {
-                        "value": "v100",
-                        "name": "V100"
-                    },
-                    {
-                        "value": "k80",
-                        "name": "K80"
-                    },
-                    {
-                        "value": "t4",
-                        "name": "T4"
-                    },
-                    {
-                        "value": "m60",
-                        "name": "M60"
-                    },
-                    {
-                        "value": "radeon-pro-v520",
-                        "name": "RADEON_PRO_V520"
-                    },
-                    {
-                        "value": "vu9p",
-                        "name": "VU9P"
-                    },
-                    {
-                        "value": "inferentia",
-                        "name": "INFERENTIA"
-                    },
-                    {
-                        "value": "k520",
-                        "name": "K520"
+            "type": "enum",
+            "members": {
+                "A100": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "a100"
                     }
-                ]
+                },
+                "V100": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "v100"
+                    }
+                },
+                "K80": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "k80"
+                    }
+                },
+                "T4": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "t4"
+                    }
+                },
+                "M60": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m60"
+                    }
+                },
+                "RADEON_PRO_V520": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "radeon-pro-v520"
+                    }
+                },
+                "VU9P": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vu9p"
+                    }
+                },
+                "INFERENTIA": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "inferentia"
+                    }
+                },
+                "K520": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "k520"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AcceleratorNameSet": {
@@ -164,6 +194,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Min",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum amount of accelerator memory, in MiB. If this parameter is not specified,\n         there is no minimum limit.</p>",
                         "smithy.api#xmlName": "min"
                     }
@@ -172,6 +204,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Max",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum amount of accelerator memory, in MiB. If this parameter is not specified,\n         there is no maximum limit.</p>",
                         "smithy.api#xmlName": "max"
                     }
@@ -187,12 +221,16 @@
                 "Min": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum amount of accelerator memory, in MiB. To specify no minimum limit, omit this\n         parameter.</p>"
                     }
                 },
                 "Max": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum amount of accelerator memory, in MiB. To specify no maximum limit, omit this\n         parameter.</p>"
                     }
                 }
@@ -202,22 +240,26 @@
             }
         },
         "com.amazonaws.ec2#AcceleratorType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "gpu",
-                        "name": "GPU"
-                    },
-                    {
-                        "value": "fpga",
-                        "name": "FPGA"
-                    },
-                    {
-                        "value": "inference",
-                        "name": "INFERENCE"
+            "type": "enum",
+            "members": {
+                "GPU": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "gpu"
                     }
-                ]
+                },
+                "FPGA": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fpga"
+                    }
+                },
+                "INFERENCE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "inference"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AcceleratorTypeSet": {
@@ -247,12 +289,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n      and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n      Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ReservedInstanceIds": {
                     "target": "com.amazonaws.ec2#ReservedInstanceIdSet",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the Convertible Reserved Instances to exchange for another Convertible\n            Reserved Instance of the same or higher value.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ReservedInstanceId"
@@ -322,6 +367,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -357,6 +404,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -364,6 +412,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -400,6 +450,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -407,6 +458,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -443,12 +496,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ServiceId": {
                     "target": "com.amazonaws.ec2#VpcEndpointServiceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC endpoint service.</p>",
                         "smithy.api#required": {}
                     }
@@ -456,6 +512,7 @@
                 "VpcEndpointIds": {
                     "target": "com.amazonaws.ec2#VpcEndpointIdList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of one or more interface VPC endpoints.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "VpcEndpointId"
@@ -495,6 +552,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -682,18 +741,20 @@
             }
         },
         "com.amazonaws.ec2#AccountAttributeName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "supported-platforms",
-                        "name": "supported_platforms"
-                    },
-                    {
-                        "value": "default-vpc",
-                        "name": "default_vpc"
+            "type": "enum",
+            "members": {
+                "supported_platforms": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "supported-platforms"
                     }
-                ]
+                },
+                "default_vpc": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "default-vpc"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AccountAttributeNameStringList": {
@@ -780,26 +841,32 @@
             }
         },
         "com.amazonaws.ec2#ActivityStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "error",
-                        "name": "ERROR"
-                    },
-                    {
-                        "value": "pending_fulfillment",
-                        "name": "PENDING_FULFILLMENT"
-                    },
-                    {
-                        "value": "pending_termination",
-                        "name": "PENDING_TERMINATION"
-                    },
-                    {
-                        "value": "fulfilled",
-                        "name": "FULFILLED"
+            "type": "enum",
+            "members": {
+                "ERROR": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "error"
                     }
-                ]
+                },
+                "PENDING_FULFILLMENT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending_fulfillment"
+                    }
+                },
+                "PENDING_TERMINATION": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending_termination"
+                    }
+                },
+                "FULFILLED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fulfilled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AddIpamOperatingRegion": {
@@ -846,6 +913,7 @@
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR block.</p>",
                         "smithy.api#required": {}
                     }
@@ -861,6 +929,55 @@
                 "smithy.api#documentation": "<p>An entry for a prefix list.</p>"
             }
         },
+        "com.amazonaws.ec2#AddedPrincipal": {
+            "type": "structure",
+            "members": {
+                "PrincipalType": {
+                    "target": "com.amazonaws.ec2#PrincipalType",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "PrincipalType",
+                        "smithy.api#documentation": "<p>The type of principal.</p>",
+                        "smithy.api#xmlName": "principalType"
+                    }
+                },
+                "Principal": {
+                    "target": "com.amazonaws.ec2#String",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "Principal",
+                        "smithy.api#documentation": "<p>The Amazon Resource Name (ARN) of the principal.</p>",
+                        "smithy.api#xmlName": "principal"
+                    }
+                },
+                "ServicePermissionId": {
+                    "target": "com.amazonaws.ec2#String",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "ServicePermissionId",
+                        "smithy.api#documentation": "<p>The ID of the service permission.</p>",
+                        "smithy.api#xmlName": "servicePermissionId"
+                    }
+                },
+                "ServiceId": {
+                    "target": "com.amazonaws.ec2#String",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "ServiceId",
+                        "smithy.api#documentation": "<p>The ID of the service.</p>",
+                        "smithy.api#xmlName": "serviceId"
+                    }
+                }
+            },
+            "traits": {
+                "smithy.api#documentation": "<p>Describes a principal.</p>"
+            }
+        },
+        "com.amazonaws.ec2#AddedPrincipalSet": {
+            "type": "list",
+            "member": {
+                "target": "com.amazonaws.ec2#AddedPrincipal",
+                "traits": {
+                    "smithy.api#xmlName": "item"
+                }
+            }
+        },
         "com.amazonaws.ec2#AdditionalDetail": {
             "type": "structure",
             "members": {
@@ -1055,29 +1172,31 @@
             }
         },
         "com.amazonaws.ec2#AddressAttributeName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "domain-name",
-                        "name": "domain_name"
+            "type": "enum",
+            "members": {
+                "domain_name": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "domain-name"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#AddressFamily": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ipv4",
-                        "name": "ipv4"
-                    },
-                    {
-                        "value": "ipv6",
-                        "name": "ipv6"
+            "type": "enum",
+            "members": {
+                "ipv4": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv4"
                     }
-                ]
+                },
+                "ipv6": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv6"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AddressList": {
@@ -1092,6 +1211,7 @@
         "com.amazonaws.ec2#AddressMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 1000
@@ -1125,6 +1245,7 @@
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The address range, in CIDR notation. This must be the exact range that you provisioned. \n         You can't advertise only a portion of the provisioned range.</p>",
                         "smithy.api#required": {}
                     }
@@ -1132,6 +1253,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -1151,18 +1274,20 @@
             }
         },
         "com.amazonaws.ec2#Affinity": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "default",
-                        "name": "default"
-                    },
-                    {
-                        "value": "host",
-                        "name": "host"
+            "type": "enum",
+            "members": {
+                "default": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "default"
                     }
-                ]
+                },
+                "host": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "host"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AllocateAddress": {
@@ -1214,6 +1339,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -1323,6 +1450,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AvailabilityZone",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Availability Zone in which to allocate the Dedicated Host.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "availabilityZone"
@@ -1354,6 +1482,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Quantity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of Dedicated Hosts to allocate to your account with these parameters.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "quantity"
@@ -1414,12 +1544,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamPoolId": {
                     "target": "com.amazonaws.ec2#IpamPoolId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPAM pool from which you would like to allocate a CIDR.</p>",
                         "smithy.api#required": {}
                     }
@@ -1433,6 +1566,8 @@
                 "NetmaskLength": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The netmask length of the CIDR you would like to allocate from the IPAM pool. Note the following:</p>\n         <ul>\n            <li>\n               <p>If there is no DefaultNetmaskLength allocation rule set on the pool, you must specify either the NetmaskLength or the CIDR.</p>\n            </li>\n            <li>\n               <p>If the DefaultNetmaskLength allocation rule is set on the pool, you can specify either the NetmaskLength or the CIDR and the DefaultNetmaskLength allocation rule will be ignored.</p>\n            </li>\n         </ul>\n         <p>Possible netmask lengths for IPv4 addresses are 0 - 32. Possible netmask lengths for IPv6 addresses are 0 - 128.</p>"
                     }
                 },
@@ -1452,6 +1587,8 @@
                 "PreviewNextCidr": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A preview of the next available CIDR in a pool.</p>"
                     }
                 },
@@ -1499,57 +1636,73 @@
             }
         },
         "com.amazonaws.ec2#AllocationState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "under-assessment",
-                        "name": "under_assessment"
-                    },
-                    {
-                        "value": "permanent-failure",
-                        "name": "permanent_failure"
-                    },
-                    {
-                        "value": "released",
-                        "name": "released"
-                    },
-                    {
-                        "value": "released-permanent-failure",
-                        "name": "released_permanent_failure"
-                    },
-                    {
-                        "value": "pending",
-                        "name": "pending"
+            "type": "enum",
+            "members": {
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
                     }
-                ]
+                },
+                "under_assessment": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "under-assessment"
+                    }
+                },
+                "permanent_failure": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "permanent-failure"
+                    }
+                },
+                "released": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "released"
+                    }
+                },
+                "released_permanent_failure": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "released-permanent-failure"
+                    }
+                },
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AllocationStrategy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "lowestPrice",
-                        "name": "LOWEST_PRICE"
-                    },
-                    {
-                        "value": "diversified",
-                        "name": "DIVERSIFIED"
-                    },
-                    {
-                        "value": "capacityOptimized",
-                        "name": "CAPACITY_OPTIMIZED"
-                    },
-                    {
-                        "value": "capacityOptimizedPrioritized",
-                        "name": "CAPACITY_OPTIMIZED_PRIORITIZED"
+            "type": "enum",
+            "members": {
+                "LOWEST_PRICE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "lowestPrice"
                     }
-                ]
+                },
+                "DIVERSIFIED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "diversified"
+                    }
+                },
+                "CAPACITY_OPTIMIZED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "capacityOptimized"
+                    }
+                },
+                "CAPACITY_OPTIMIZED_PRIORITIZED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "capacityOptimizedPrioritized"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AllowedPrincipal": {
@@ -1570,6 +1723,30 @@
                         "smithy.api#documentation": "<p>The Amazon Resource Name (ARN) of the principal.</p>",
                         "smithy.api#xmlName": "principal"
                     }
+                },
+                "ServicePermissionId": {
+                    "target": "com.amazonaws.ec2#String",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "ServicePermissionId",
+                        "smithy.api#documentation": "<p>The ID of the service permission.</p>",
+                        "smithy.api#xmlName": "servicePermissionId"
+                    }
+                },
+                "Tags": {
+                    "target": "com.amazonaws.ec2#TagList",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "TagSet",
+                        "smithy.api#documentation": "<p>The tags.</p>",
+                        "smithy.api#xmlName": "tagSet"
+                    }
+                },
+                "ServiceId": {
+                    "target": "com.amazonaws.ec2#String",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "ServiceId",
+                        "smithy.api#documentation": "<p>The ID of the service.</p>",
+                        "smithy.api#xmlName": "serviceId"
+                    }
                 }
             },
             "traits": {
@@ -1586,18 +1763,20 @@
             }
         },
         "com.amazonaws.ec2#AllowsMultipleInstanceTypes": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "on",
-                        "name": "on"
-                    },
-                    {
-                        "value": "off",
-                        "name": "off"
+            "type": "enum",
+            "members": {
+                "on": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "on"
                     }
-                ]
+                },
+                "off": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "off"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AlternatePathHint": {
@@ -1635,24 +1814,6 @@
         },
         "com.amazonaws.ec2#AmazonEC2": {
             "type": "service",
-            "traits": {
-                "aws.api#service": {
-                    "sdkId": "EC2",
-                    "arnNamespace": "ec2",
-                    "cloudFormationName": "EC2",
-                    "cloudTrailEventSource": "ec2.amazonaws.com",
-                    "endpointPrefix": "ec2"
-                },
-                "aws.auth#sigv4": {
-                    "name": "ec2"
-                },
-                "aws.protocols#ec2Query": {},
-                "smithy.api#documentation": "<fullname>Amazon Elastic Compute Cloud</fullname>\n         <p>Amazon Elastic Compute Cloud (Amazon EC2) provides secure and resizable computing capacity in the Amazon Web Services Cloud. \n          Using Amazon EC2 eliminates the need to invest in hardware up front, so you can develop and deploy applications \n          faster. Amazon Virtual Private Cloud (Amazon VPC) enables you to provision a logically isolated section of the \n          Amazon Web Services Cloud where you can launch Amazon Web Services resources in a virtual network that you've defined. Amazon Elastic Block Store \n          (Amazon EBS) provides block level storage volumes for use with EC2 instances. EBS volumes are highly available  \n          and reliable storage volumes that can be attached to any running instance and used like a hard drive.</p>\n         <p>To learn more, see the following resources:</p>\n         <ul>\n            <li>\n               <p>Amazon EC2: <a href=\"http://aws.amazon.com/ec2\">AmazonEC2 product page</a>, <a href=\"http://aws.amazon.com/documentation/ec2\">Amazon EC2 documentation</a>\n               </p>\n            </li>\n            <li>\n               <p>Amazon EBS: <a href=\"http://aws.amazon.com/ebs\">Amazon EBS product page</a>, <a href=\"http://aws.amazon.com/documentation/ebs\">Amazon EBS documentation</a>\n               </p>\n            </li>\n            <li>\n               <p>Amazon VPC: <a href=\"http://aws.amazon.com/vpc\">Amazon VPC product page</a>, <a href=\"http://aws.amazon.com/documentation/vpc\">Amazon VPC documentation</a>\n               </p>\n            </li>\n            <li>\n               <p>Amazon Web Services VPN: <a href=\"http://aws.amazon.com/vpn\">Amazon Web Services VPN product page</a>, <a href=\"http://aws.amazon.com/documentation/vpn\">Amazon Web Services VPN documentation</a>\n               </p>\n            </li>\n         </ul>",
-                "smithy.api#title": "Amazon Elastic Compute Cloud",
-                "smithy.api#xmlNamespace": {
-                    "uri": "http://ec2.amazonaws.com/doc/2016-11-15"
-                }
-            },
             "version": "2016-11-15",
             "operations": [
                 {
@@ -3281,7 +3442,25 @@
                 {
                     "target": "com.amazonaws.ec2#WithdrawByoipCidr"
                 }
-            ]
+            ],
+            "traits": {
+                "aws.api#service": {
+                    "sdkId": "EC2",
+                    "arnNamespace": "ec2",
+                    "cloudFormationName": "EC2",
+                    "cloudTrailEventSource": "ec2.amazonaws.com",
+                    "endpointPrefix": "ec2"
+                },
+                "aws.auth#sigv4": {
+                    "name": "ec2"
+                },
+                "aws.protocols#ec2Query": {},
+                "smithy.api#documentation": "<fullname>Amazon Elastic Compute Cloud</fullname>\n         <p>Amazon Elastic Compute Cloud (Amazon EC2) provides secure and resizable computing capacity in the Amazon Web Services Cloud. \n          Using Amazon EC2 eliminates the need to invest in hardware up front, so you can develop and deploy applications \n          faster. Amazon Virtual Private Cloud (Amazon VPC) enables you to provision a logically isolated section of the \n          Amazon Web Services Cloud where you can launch Amazon Web Services resources in a virtual network that you've defined. Amazon Elastic Block Store \n          (Amazon EBS) provides block level storage volumes for use with EC2 instances. EBS volumes are highly available  \n          and reliable storage volumes that can be attached to any running instance and used like a hard drive.</p>\n         <p>To learn more, see the following resources:</p>\n         <ul>\n            <li>\n               <p>Amazon EC2: <a href=\"http://aws.amazon.com/ec2\">AmazonEC2 product page</a>, <a href=\"http://aws.amazon.com/documentation/ec2\">Amazon EC2 documentation</a>\n               </p>\n            </li>\n            <li>\n               <p>Amazon EBS: <a href=\"http://aws.amazon.com/ebs\">Amazon EBS product page</a>, <a href=\"http://aws.amazon.com/documentation/ebs\">Amazon EBS documentation</a>\n               </p>\n            </li>\n            <li>\n               <p>Amazon VPC: <a href=\"http://aws.amazon.com/vpc\">Amazon VPC product page</a>, <a href=\"http://aws.amazon.com/documentation/vpc\">Amazon VPC documentation</a>\n               </p>\n            </li>\n            <li>\n               <p>Amazon Web Services VPN: <a href=\"http://aws.amazon.com/vpn\">Amazon Web Services VPN product page</a>, <a href=\"http://aws.amazon.com/documentation/vpn\">Amazon Web Services VPN documentation</a>\n               </p>\n            </li>\n         </ul>",
+                "smithy.api#title": "Amazon Elastic Compute Cloud",
+                "smithy.api#xmlNamespace": {
+                    "uri": "http://ec2.amazonaws.com/doc/2016-11-15"
+                }
+            }
         },
         "com.amazonaws.ec2#AnalysisAclRule": {
             "type": "structure",
@@ -3298,6 +3477,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Egress",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the rule is an outbound rule.</p>",
                         "smithy.api#xmlName": "egress"
                     }
@@ -3330,6 +3511,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RuleNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The rule number.</p>",
                         "smithy.api#xmlName": "ruleNumber"
                     }
@@ -3387,6 +3570,8 @@
                     "target": "com.amazonaws.ec2#Port",
                     "traits": {
                         "aws.protocols#ec2QueryName": "LoadBalancerPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The port on which the load balancer is listening.</p>",
                         "smithy.api#xmlName": "loadBalancerPort"
                     }
@@ -3395,6 +3580,8 @@
                     "target": "com.amazonaws.ec2#Port",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstancePort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>[Classic Load Balancers] The back-end port for the listener.</p>",
                         "smithy.api#xmlName": "instancePort"
                     }
@@ -3435,6 +3622,8 @@
                     "target": "com.amazonaws.ec2#Port",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Port",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The port on which the target is listening.</p>",
                         "smithy.api#xmlName": "port"
                     }
@@ -3637,37 +3826,43 @@
             }
         },
         "com.amazonaws.ec2#AnalysisStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "running",
-                        "name": "running"
-                    },
-                    {
-                        "value": "succeeded",
-                        "name": "succeeded"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
+            "type": "enum",
+            "members": {
+                "running": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "running"
                     }
-                ]
+                },
+                "succeeded": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "succeeded"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ApplianceModeSupportValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ApplySecurityGroupsToClientVpnTargetNetwork": {
@@ -3688,6 +3883,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint.</p>",
                         "smithy.api#required": {}
                     }
@@ -3695,6 +3891,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC in which the associated target network is located.</p>",
                         "smithy.api#required": {}
                     }
@@ -3702,6 +3899,7 @@
                 "SecurityGroupIds": {
                     "target": "com.amazonaws.ec2#ClientVpnSecurityGroupIdSet",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the security groups to apply to the associated target network. Up to 5 security groups can \n\t\t\tbe applied to an associated target network.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "SecurityGroupId"
@@ -3710,6 +3908,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -3729,26 +3929,32 @@
             }
         },
         "com.amazonaws.ec2#ArchitectureType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "i386",
-                        "name": "i386"
-                    },
-                    {
-                        "value": "x86_64",
-                        "name": "x86_64"
-                    },
-                    {
-                        "value": "arm64",
-                        "name": "arm64"
-                    },
-                    {
-                        "value": "x86_64_mac",
-                        "name": "x86_64_mac"
+            "type": "enum",
+            "members": {
+                "i386": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "i386"
                     }
-                ]
+                },
+                "x86_64": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "x86_64"
+                    }
+                },
+                "arm64": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "arm64"
+                    }
+                },
+                "x86_64_mac": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "x86_64_mac"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ArchitectureTypeList": {
@@ -3776,26 +3982,32 @@
             }
         },
         "com.amazonaws.ec2#ArchitectureValues": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "i386",
-                        "name": "i386"
-                    },
-                    {
-                        "value": "x86_64",
-                        "name": "x86_64"
-                    },
-                    {
-                        "value": "arm64",
-                        "name": "arm64"
-                    },
-                    {
-                        "value": "x86_64_mac",
-                        "name": "x86_64_mac"
+            "type": "enum",
+            "members": {
+                "i386": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "i386"
                     }
-                ]
+                },
+                "x86_64": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "x86_64"
+                    }
+                },
+                "arm64": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "arm64"
+                    }
+                },
+                "x86_64_mac": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "x86_64_mac"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ArnList": {
@@ -3826,6 +4038,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Ipv6AddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of additional IPv6 addresses to assign to the network interface. \n    \t\tThe specified number of IPv6 addresses are assigned in addition to the \n    \t\texisting IPv6 addresses that are already assigned to the network interface. \n    \t\tAmazon EC2 automatically selects the IPv6 addresses from the subnet range. You \n    \t\tcan't use this option if specifying specific IPv6 addresses.</p>",
                         "smithy.api#xmlName": "ipv6AddressCount"
                     }
@@ -3841,6 +4055,8 @@
                 "Ipv6PrefixCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv6 prefixes that Amazon Web Services automatically assigns to the\n            network interface. You cannot use this option if you use the <code>Ipv6Prefixes</code>\n            option.</p>"
                     }
                 },
@@ -3855,6 +4071,7 @@
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkInterfaceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network interface.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkInterfaceId"
@@ -3910,6 +4127,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AllowReassignment",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to allow an IP address that is already assigned to another network interface or instance to be reassigned to the specified network interface.</p>",
                         "smithy.api#xmlName": "allowReassignment"
                     }
@@ -3918,6 +4137,7 @@
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkInterfaceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network interface.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkInterfaceId"
@@ -3935,6 +4155,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SecondaryPrivateIpAddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of secondary IP addresses to assign to the network interface. You can't specify this parameter when also specifying private IP addresses.</p>",
                         "smithy.api#xmlName": "secondaryPrivateIpAddressCount"
                     }
@@ -3949,6 +4171,8 @@
                 "Ipv4PrefixCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv4 prefixes that Amazon Web Services automatically assigns to the network interface. You cannot use this option if you use the <code>Ipv4 Prefixes</code> option.</p>"
                     }
                 }
@@ -4048,6 +4272,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AllowReassociation",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>[EC2-VPC] For a VPC in an EC2-Classic account, specify true to allow an Elastic IP address that is already associated with an instance or network interface to be reassociated with the specified instance or network interface. Otherwise, the operation fails. In a VPC in an EC2-VPC-only account, reassociation is automatic, therefore you can specify false to ensure the operation fails if the Elastic IP address is already associated with another resource.</p>",
                         "smithy.api#xmlName": "allowReassociation"
                     }
@@ -4056,6 +4282,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -4109,6 +4337,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint.</p>",
                         "smithy.api#required": {}
                     }
@@ -4116,6 +4345,7 @@
                 "SubnetId": {
                     "target": "com.amazonaws.ec2#SubnetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the subnet to associate with the Client VPN endpoint.</p>",
                         "smithy.api#required": {}
                     }
@@ -4130,6 +4360,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -4174,6 +4406,7 @@
                 "DhcpOptionsId": {
                     "target": "com.amazonaws.ec2#DefaultingDhcpOptionsId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the DHCP options set, or <code>default</code> to associate \n        no DHCP options with the VPC.</p>",
                         "smithy.api#required": {}
                     }
@@ -4181,6 +4414,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {}
                     }
@@ -4189,6 +4423,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -4225,6 +4461,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -4277,6 +4515,7 @@
                 "IamInstanceProfile": {
                     "target": "com.amazonaws.ec2#IamInstanceProfileSpecification",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IAM instance profile.</p>",
                         "smithy.api#required": {}
                     }
@@ -4284,6 +4523,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {}
                     }
@@ -4321,12 +4561,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "InstanceEventWindowId": {
                     "target": "com.amazonaws.ec2#InstanceEventWindowId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the event window.</p>",
                         "smithy.api#required": {}
                     }
@@ -4334,6 +4577,7 @@
                 "AssociationTarget": {
                     "target": "com.amazonaws.ec2#InstanceEventWindowAssociationRequest",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>One or more targets associated with the specified event window.</p>",
                         "smithy.api#required": {}
                     }
@@ -4372,6 +4616,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -4380,6 +4626,7 @@
                     "target": "com.amazonaws.ec2#RouteTableId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RouteTableId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the route table.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "routeTableId"
@@ -4441,6 +4688,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Ipv6CidrBlock",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IPv6 CIDR block for your subnet. The subnet must have a /64 prefix\n            length.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ipv6CidrBlock"
@@ -4450,6 +4698,7 @@
                     "target": "com.amazonaws.ec2#SubnetId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SubnetId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of your subnet.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "subnetId"
@@ -4514,6 +4763,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -4550,6 +4801,7 @@
                 "TransitGatewayPolicyTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayPolicyTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway policy table to associate with the transit gateway attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -4557,6 +4809,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway attachment to associate with the policy table.</p>",
                         "smithy.api#required": {}
                     }
@@ -4564,6 +4817,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -4600,6 +4855,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -4607,6 +4863,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -4614,6 +4871,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -4650,6 +4909,7 @@
                 "BranchInterfaceId": {
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the branch network interface.</p>",
                         "smithy.api#required": {}
                     }
@@ -4657,6 +4917,7 @@
                 "TrunkInterfaceId": {
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the trunk network interface.</p>",
                         "smithy.api#required": {}
                     }
@@ -4664,12 +4925,16 @@
                 "VlanId": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The ID of the VLAN. This applies to the VLAN protocol.</p>"
                     }
                 },
                 "GreKey": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The application key. This applies to the GRE protocol.</p>"
                     }
                 },
@@ -4683,6 +4948,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -4728,6 +4995,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AmazonProvidedIpv6CidrBlock",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Requests an Amazon-provided IPv6 CIDR block with a /56 prefix length for the VPC. You cannot specify the range of IPv6 addresses, or the size of the CIDR block.</p>",
                         "smithy.api#xmlName": "amazonProvidedIpv6CidrBlock"
                     }
@@ -4742,6 +5011,7 @@
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcId"
@@ -4821,14 +5091,14 @@
             }
         },
         "com.amazonaws.ec2#AssociatedNetworkType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "vpc",
-                        "name": "vpc"
+            "type": "enum",
+            "members": {
+                "vpc": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vpc"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#AssociatedRole": {
@@ -4947,30 +5217,38 @@
             }
         },
         "com.amazonaws.ec2#AssociationStatusCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "associating",
-                        "name": "associating"
-                    },
-                    {
-                        "value": "associated",
-                        "name": "associated"
-                    },
-                    {
-                        "value": "association-failed",
-                        "name": "association_failed"
-                    },
-                    {
-                        "value": "disassociating",
-                        "name": "disassociating"
-                    },
-                    {
-                        "value": "disassociated",
-                        "name": "disassociated"
+            "type": "enum",
+            "members": {
+                "associating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associating"
                     }
-                ]
+                },
+                "associated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associated"
+                    }
+                },
+                "association_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "association-failed"
+                    }
+                },
+                "disassociating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociating"
+                    }
+                },
+                "disassociated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociated"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AthenaIntegration": {
@@ -4979,6 +5257,7 @@
                 "IntegrationResultS3DestinationArn": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The location in Amazon S3 to store the generated CloudFormation template.</p>",
                         "smithy.api#required": {}
                     }
@@ -4986,6 +5265,7 @@
                 "PartitionLoadFrequency": {
                     "target": "com.amazonaws.ec2#PartitionLoadFrequency",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The schedule for adding new partitions to the table.</p>",
                         "smithy.api#required": {}
                     }
@@ -5041,6 +5321,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -5048,6 +5330,7 @@
                 "Groups": {
                     "target": "com.amazonaws.ec2#GroupIdStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of one or more of the VPC's security groups. You cannot specify security groups from a different VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "SecurityGroupId"
@@ -5057,6 +5340,7 @@
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of an EC2-Classic instance to link to the ClassicLink-enabled VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "instanceId"
@@ -5066,6 +5350,7 @@
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of a ClassicLink-enabled VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcId"
@@ -5080,6 +5365,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -5105,6 +5392,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -5113,6 +5402,7 @@
                     "target": "com.amazonaws.ec2#InternetGatewayId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InternetGatewayId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the internet gateway.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "internetGatewayId"
@@ -5122,6 +5412,7 @@
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcId"
@@ -5148,6 +5439,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeviceIndex",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The index of the device for the network interface attachment.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "deviceIndex"
@@ -5157,6 +5450,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n            and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n            Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -5165,6 +5460,7 @@
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "instanceId"
@@ -5174,6 +5470,7 @@
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkInterfaceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network interface.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkInterfaceId"
@@ -5182,6 +5479,8 @@
                 "NetworkCardIndex": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The index of the network card. Some instance types support multiple network cards. \n            The primary network interface must be assigned to network card index 0. \n            The default is network card index 0.</p>"
                     }
                 }
@@ -5205,6 +5504,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkCardIndex",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The index of the network card.</p>",
                         "smithy.api#xmlName": "networkCardIndex"
                     }
@@ -5232,6 +5533,7 @@
                 "Device": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The device name (for example, <code>/dev/sdh</code> or <code>xvdh</code>).</p>",
                         "smithy.api#required": {}
                     }
@@ -5239,6 +5541,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {}
                     }
@@ -5246,6 +5549,7 @@
                 "VolumeId": {
                     "target": "com.amazonaws.ec2#VolumeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the EBS volume. The volume and instance must be within the same Availability\n      Zone.</p>",
                         "smithy.api#required": {}
                     }
@@ -5254,6 +5558,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -5278,6 +5584,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {}
                     }
@@ -5285,6 +5592,7 @@
                 "VpnGatewayId": {
                     "target": "com.amazonaws.ec2#VpnGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the virtual private gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -5293,6 +5601,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -5319,26 +5629,32 @@
             }
         },
         "com.amazonaws.ec2#AttachmentStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "attaching",
-                        "name": "attaching"
-                    },
-                    {
-                        "value": "attached",
-                        "name": "attached"
-                    },
-                    {
-                        "value": "detaching",
-                        "name": "detaching"
-                    },
-                    {
-                        "value": "detached",
-                        "name": "detached"
+            "type": "enum",
+            "members": {
+                "attaching": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "attaching"
                     }
-                ]
+                },
+                "attached": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "attached"
+                    }
+                },
+                "detaching": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "detaching"
+                    }
+                },
+                "detached": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "detached"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AttributeBooleanValue": {
@@ -5348,6 +5664,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Value",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>The attribute value. The valid values are <code>true</code> or <code>false</code>.</p>",
                         "smithy.api#xmlName": "value"
                     }
@@ -5404,6 +5722,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AccessAll",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the authorization rule grants access to all clients.</p>",
                         "smithy.api#xmlName": "accessAll"
                     }
@@ -5456,6 +5776,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint.</p>",
                         "smithy.api#required": {}
                     }
@@ -5463,6 +5784,7 @@
                 "TargetNetworkCidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IPv4 address range, in CIDR notation, of the network for which access is being authorized.</p>",
                         "smithy.api#required": {}
                     }
@@ -5476,6 +5798,8 @@
                 "AuthorizeAllGroups": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to grant access to all clients. Specify <code>true</code> to grant all\n            clients who successfully establish a VPN connection access to the network. Must be set\n            to <code>true</code> if <code>AccessGroupId</code> is not specified.</p>"
                     }
                 },
@@ -5495,6 +5819,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -5532,6 +5858,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -5540,6 +5868,7 @@
                     "target": "com.amazonaws.ec2#SecurityGroupId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "GroupId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the security group.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "groupId"
@@ -5572,6 +5901,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FromPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>Not supported. Use a set of IP permissions to specify the port.</p>",
                         "smithy.api#xmlName": "fromPort"
                     }
@@ -5588,6 +5919,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ToPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>Not supported. Use a set of IP permissions to specify the port.</p>",
                         "smithy.api#xmlName": "toPort"
                     }
@@ -5617,6 +5950,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -5655,6 +5990,8 @@
                 "FromPort": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The start of port range for the TCP and UDP protocols, or an ICMP type number.\n\t\t\tFor the ICMP type number, use <code>-1</code> to specify all types. If you\n\t\t\tspecify all ICMP types, you must specify all codes.</p>\n         <p>Alternatively, use a set of IP permissions to specify multiple rules and a description for the rule.</p>"
                     }
                 },
@@ -5697,6 +6034,8 @@
                 "ToPort": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The end of port range for the TCP and UDP protocols, or an ICMP code number.\n\t\t\tFor the ICMP code number, use <code>-1</code> to specify all codes. If you\n\t\t\tspecify all ICMP types, you must specify all codes.</p>\n         <p>Alternatively, use a set of IP permissions to specify multiple rules and a description for the rule.</p>"
                     }
                 },
@@ -5704,6 +6043,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -5724,6 +6065,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -5739,55 +6082,58 @@
             }
         },
         "com.amazonaws.ec2#AutoAcceptSharedAssociationsValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AutoAcceptSharedAttachmentsValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AutoPlacement": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "on",
-                        "name": "on"
-                    },
-                    {
-                        "value": "off",
-                        "name": "off"
+            "type": "enum",
+            "members": {
+                "on": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "on"
                     }
-                ]
+                },
+                "off": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "off"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AutoRecoveryFlag": {
-            "type": "boolean",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "boolean"
         },
         "com.amazonaws.ec2#AvailabilityZone": {
             "type": "structure",
@@ -5920,45 +6266,55 @@
             }
         },
         "com.amazonaws.ec2#AvailabilityZoneOptInStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "opt-in-not-required",
-                        "name": "opt_in_not_required"
-                    },
-                    {
-                        "value": "opted-in",
-                        "name": "opted_in"
-                    },
-                    {
-                        "value": "not-opted-in",
-                        "name": "not_opted_in"
+            "type": "enum",
+            "members": {
+                "opt_in_not_required": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "opt-in-not-required"
                     }
-                ]
+                },
+                "opted_in": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "opted-in"
+                    }
+                },
+                "not_opted_in": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "not-opted-in"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AvailabilityZoneState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "information",
-                        "name": "information"
-                    },
-                    {
-                        "value": "impaired",
-                        "name": "impaired"
-                    },
-                    {
-                        "value": "unavailable",
-                        "name": "unavailable"
+            "type": "enum",
+            "members": {
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
                     }
-                ]
+                },
+                "information": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "information"
+                    }
+                },
+                "impaired": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "impaired"
+                    }
+                },
+                "unavailable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unavailable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#AvailabilityZoneStringList": {
@@ -5985,6 +6341,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AvailableVCpus",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of vCPUs available for launching instances onto the Dedicated Host.</p>",
                         "smithy.api#xmlName": "availableVCpus"
                     }
@@ -6004,35 +6362,33 @@
             }
         },
         "com.amazonaws.ec2#BareMetal": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "included",
-                        "name": "INCLUDED"
-                    },
-                    {
-                        "value": "required",
-                        "name": "REQUIRED"
-                    },
-                    {
-                        "value": "excluded",
-                        "name": "EXCLUDED"
+            "type": "enum",
+            "members": {
+                "INCLUDED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "included"
                     }
-                ]
+                },
+                "REQUIRED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "required"
+                    }
+                },
+                "EXCLUDED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "excluded"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#BareMetalFlag": {
-            "type": "boolean",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "boolean"
         },
         "com.amazonaws.ec2#BaselineBandwidthInMbps": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#BaselineEbsBandwidthMbps": {
             "type": "structure",
@@ -6041,6 +6397,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Min",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum baseline bandwidth, in Mbps. If this parameter is not specified, there is no\n         minimum limit.</p>",
                         "smithy.api#xmlName": "min"
                     }
@@ -6049,6 +6407,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Max",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum baseline bandwidth, in Mbps. If this parameter is not specified, there is no\n         maximum limit.</p>",
                         "smithy.api#xmlName": "max"
                     }
@@ -6064,12 +6424,16 @@
                 "Min": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum baseline bandwidth, in Mbps. To specify no minimum limit, omit\n         this parameter.</p>"
                     }
                 },
                 "Max": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum baseline bandwidth, in Mbps. To specify no maximum limit, omit\n         this parameter.</p>"
                     }
                 }
@@ -6079,65 +6443,73 @@
             }
         },
         "com.amazonaws.ec2#BaselineIops": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#BaselineThroughputInMBps": {
-            "type": "double",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "double"
         },
         "com.amazonaws.ec2#BatchState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "submitted",
-                        "name": "SUBMITTED"
-                    },
-                    {
-                        "value": "active",
-                        "name": "ACTIVE"
-                    },
-                    {
-                        "value": "cancelled",
-                        "name": "CANCELLED"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "FAILED"
-                    },
-                    {
-                        "value": "cancelled_running",
-                        "name": "CANCELLED_RUNNING"
-                    },
-                    {
-                        "value": "cancelled_terminating",
-                        "name": "CANCELLED_TERMINATING_INSTANCES"
-                    },
-                    {
-                        "value": "modifying",
-                        "name": "MODIFYING"
+            "type": "enum",
+            "members": {
+                "SUBMITTED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "submitted"
                     }
-                ]
+                },
+                "ACTIVE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "CANCELLED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelled"
+                    }
+                },
+                "FAILED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "CANCELLED_RUNNING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelled_running"
+                    }
+                },
+                "CANCELLED_TERMINATING_INSTANCES": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelled_terminating"
+                    }
+                },
+                "MODIFYING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modifying"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#BgpStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "up",
-                        "name": "up"
-                    },
-                    {
-                        "value": "down",
-                        "name": "down"
+            "type": "enum",
+            "members": {
+                "up": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "up"
                     }
-                ]
+                },
+                "down": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "down"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#BillingProductList": {
@@ -6223,21 +6595,26 @@
             }
         },
         "com.amazonaws.ec2#Boolean": {
-            "type": "boolean"
+            "type": "boolean",
+            "traits": {
+                "smithy.api#default": false
+            }
         },
         "com.amazonaws.ec2#BootModeType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "legacy-bios",
-                        "name": "legacy_bios"
-                    },
-                    {
-                        "value": "uefi",
-                        "name": "uefi"
+            "type": "enum",
+            "members": {
+                "legacy_bios": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "legacy-bios"
                     }
-                ]
+                },
+                "uefi": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "uefi"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#BootModeTypeList": {
@@ -6250,25 +6627,24 @@
             }
         },
         "com.amazonaws.ec2#BootModeValues": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "legacy-bios",
-                        "name": "legacy_bios"
-                    },
-                    {
-                        "value": "uefi",
-                        "name": "uefi"
+            "type": "enum",
+            "members": {
+                "legacy_bios": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "legacy-bios"
                     }
-                ]
+                },
+                "uefi": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "uefi"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#BoxedDouble": {
-            "type": "double",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "double"
         },
         "com.amazonaws.ec2#BundleId": {
             "type": "string"
@@ -6300,6 +6676,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance to bundle.</p>\n         <p>Type: String</p>\n         <p>Default: None</p>\n         <p>Required: Yes</p>",
                         "smithy.api#required": {}
                     }
@@ -6307,6 +6684,7 @@
                 "Storage": {
                     "target": "com.amazonaws.ec2#Storage",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The bucket in which to store the AMI. You can specify a bucket that you already own or a new bucket that Amazon EC2 creates on your behalf. If you specify a bucket that belongs to someone else, Amazon EC2 returns an error.</p>",
                         "smithy.api#required": {}
                     }
@@ -6315,6 +6693,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -6446,64 +6826,77 @@
             }
         },
         "com.amazonaws.ec2#BundleTaskState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "waiting-for-shutdown",
-                        "name": "waiting_for_shutdown"
-                    },
-                    {
-                        "value": "bundling",
-                        "name": "bundling"
-                    },
-                    {
-                        "value": "storing",
-                        "name": "storing"
-                    },
-                    {
-                        "value": "cancelling",
-                        "name": "cancelling"
-                    },
-                    {
-                        "value": "complete",
-                        "name": "complete"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "waiting_for_shutdown": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "waiting-for-shutdown"
+                    }
+                },
+                "bundling": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "bundling"
+                    }
+                },
+                "storing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "storing"
+                    }
+                },
+                "cancelling": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelling"
+                    }
+                },
+                "complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "complete"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#BurstablePerformance": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "included",
-                        "name": "INCLUDED"
-                    },
-                    {
-                        "value": "required",
-                        "name": "REQUIRED"
-                    },
-                    {
-                        "value": "excluded",
-                        "name": "EXCLUDED"
+            "type": "enum",
+            "members": {
+                "INCLUDED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "included"
                     }
-                ]
+                },
+                "REQUIRED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "required"
+                    }
+                },
+                "EXCLUDED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "excluded"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#BurstablePerformanceFlag": {
-            "type": "boolean",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "boolean"
         },
         "com.amazonaws.ec2#ByoipCidr": {
             "type": "structure",
@@ -6555,65 +6948,85 @@
             }
         },
         "com.amazonaws.ec2#ByoipCidrState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "advertised",
-                        "name": "advertised"
-                    },
-                    {
-                        "value": "deprovisioned",
-                        "name": "deprovisioned"
-                    },
-                    {
-                        "value": "failed-deprovision",
-                        "name": "failed_deprovision"
-                    },
-                    {
-                        "value": "failed-provision",
-                        "name": "failed_provision"
-                    },
-                    {
-                        "value": "pending-deprovision",
-                        "name": "pending_deprovision"
-                    },
-                    {
-                        "value": "pending-provision",
-                        "name": "pending_provision"
-                    },
-                    {
-                        "value": "provisioned",
-                        "name": "provisioned"
-                    },
-                    {
-                        "value": "provisioned-not-publicly-advertisable",
-                        "name": "provisioned_not_publicly_advertisable"
+            "type": "enum",
+            "members": {
+                "advertised": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "advertised"
                     }
-                ]
+                },
+                "deprovisioned": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deprovisioned"
+                    }
+                },
+                "failed_deprovision": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed-deprovision"
+                    }
+                },
+                "failed_provision": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed-provision"
+                    }
+                },
+                "pending_deprovision": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending-deprovision"
+                    }
+                },
+                "pending_provision": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending-provision"
+                    }
+                },
+                "provisioned": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "provisioned"
+                    }
+                },
+                "provisioned_not_publicly_advertisable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "provisioned-not-publicly-advertisable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#CancelBatchErrorCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "fleetRequestIdDoesNotExist",
-                        "name": "FLEET_REQUEST_ID_DOES_NOT_EXIST"
-                    },
-                    {
-                        "value": "fleetRequestIdMalformed",
-                        "name": "FLEET_REQUEST_ID_MALFORMED"
-                    },
-                    {
-                        "value": "fleetRequestNotInCancellableState",
-                        "name": "FLEET_REQUEST_NOT_IN_CANCELLABLE_STATE"
-                    },
-                    {
-                        "value": "unexpectedError",
-                        "name": "UNEXPECTED_ERROR"
+            "type": "enum",
+            "members": {
+                "FLEET_REQUEST_ID_DOES_NOT_EXIST": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fleetRequestIdDoesNotExist"
                     }
-                ]
+                },
+                "FLEET_REQUEST_ID_MALFORMED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fleetRequestIdMalformed"
+                    }
+                },
+                "FLEET_REQUEST_NOT_IN_CANCELLABLE_STATE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fleetRequestNotInCancellableState"
+                    }
+                },
+                "UNEXPECTED_ERROR": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unexpectedError"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#CancelBundleTask": {
@@ -6634,6 +7047,7 @@
                 "BundleId": {
                     "target": "com.amazonaws.ec2#BundleId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the bundle task.</p>",
                         "smithy.api#required": {}
                     }
@@ -6642,6 +7056,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -6727,12 +7143,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "CapacityReservationFleetIds": {
                     "target": "com.amazonaws.ec2#CapacityReservationFleetIdSet",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the Capacity Reservation Fleets to cancel.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "CapacityReservationFleetId"
@@ -6767,6 +7186,7 @@
                 "CapacityReservationId": {
                     "target": "com.amazonaws.ec2#CapacityReservationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Capacity Reservation to be cancelled.</p>",
                         "smithy.api#required": {}
                     }
@@ -6774,6 +7194,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -6786,6 +7208,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -6799,6 +7223,7 @@
                     "target": "com.amazonaws.ec2#ConversionTaskId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ConversionTaskId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the conversion task.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "conversionTaskId"
@@ -6808,6 +7233,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -6853,6 +7280,7 @@
                     "target": "com.amazonaws.ec2#ExportVmTaskId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ExportTaskId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the export task. This is the ID returned by <code>CreateInstanceExportTask</code>.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "exportTaskId"
@@ -6884,6 +7312,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -6943,6 +7373,7 @@
                     "target": "com.amazonaws.ec2#ReservedInstancesListingId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ReservedInstancesListingId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Reserved Instance listing.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "reservedInstancesListingId"
@@ -7045,6 +7476,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -7053,6 +7486,7 @@
                     "target": "com.amazonaws.ec2#SpotFleetRequestIdList",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SpotFleetRequestId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the Spot Fleet requests.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "spotFleetRequestId"
@@ -7062,6 +7496,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TerminateInstances",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to terminate instances for a Spot Fleet request if it is canceled\n            successfully.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "terminateInstances"
@@ -7138,30 +7574,38 @@
             }
         },
         "com.amazonaws.ec2#CancelSpotInstanceRequestState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "open",
-                        "name": "open"
-                    },
-                    {
-                        "value": "closed",
-                        "name": "closed"
-                    },
-                    {
-                        "value": "cancelled",
-                        "name": "cancelled"
-                    },
-                    {
-                        "value": "completed",
-                        "name": "completed"
+            "type": "enum",
+            "members": {
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
                     }
-                ]
+                },
+                "open": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "open"
+                    }
+                },
+                "closed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "closed"
+                    }
+                },
+                "cancelled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelled"
+                    }
+                },
+                "completed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "completed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#CancelSpotInstanceRequests": {
@@ -7183,6 +7627,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -7190,6 +7636,7 @@
                 "SpotInstanceRequestIds": {
                     "target": "com.amazonaws.ec2#SpotInstanceRequestIdList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>One or more Spot Instance request IDs.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "SpotInstanceRequestId"
@@ -7320,6 +7767,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalInstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of instances for which the Capacity Reservation reserves capacity.</p>",
                         "smithy.api#xmlName": "totalInstanceCount"
                     }
@@ -7328,6 +7777,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AvailableInstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The remaining capacity. Indicates the number of instances that can be launched in the Capacity Reservation.</p>",
                         "smithy.api#xmlName": "availableInstanceCount"
                     }
@@ -7336,6 +7787,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EbsOptimized",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the Capacity Reservation supports EBS-optimized instances. This optimization provides\n\t\t\tdedicated throughput to Amazon EBS and an optimized configuration stack to provide\n\t\t\toptimal I/O performance. This optimization isn't available with all instance types.\n\t\t\tAdditional usage charges apply when using an EBS- optimized instance.</p>",
                         "smithy.api#xmlName": "ebsOptimized"
                     }
@@ -7344,6 +7797,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EphemeralStorage",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>\n            <i>Deprecated.</i>\n         </p>",
                         "smithy.api#xmlName": "ephemeralStorage"
                     }
@@ -7464,6 +7919,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalTargetCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of capacity units for which the Capacity Reservation Fleet reserves capacity. \n\t\t\tFor more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/crfleet-concepts.html#target-capacity\">Total target capacity</a> \n\t\t\tin the Amazon EC2 User Guide.</p>",
                         "smithy.api#xmlName": "totalTargetCapacity"
                     }
@@ -7472,6 +7929,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalFulfilledCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The capacity units that have been fulfilled.</p>",
                         "smithy.api#xmlName": "totalFulfilledCapacity"
                     }
@@ -7600,46 +8059,62 @@
             }
         },
         "com.amazonaws.ec2#CapacityReservationFleetState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "submitted",
-                        "name": "SUBMITTED"
-                    },
-                    {
-                        "value": "modifying",
-                        "name": "MODIFYING"
-                    },
-                    {
-                        "value": "active",
-                        "name": "ACTIVE"
-                    },
-                    {
-                        "value": "partially_fulfilled",
-                        "name": "PARTIALLY_FULFILLED"
-                    },
-                    {
-                        "value": "expiring",
-                        "name": "EXPIRING"
-                    },
-                    {
-                        "value": "expired",
-                        "name": "EXPIRED"
-                    },
-                    {
-                        "value": "cancelling",
-                        "name": "CANCELLING"
-                    },
-                    {
-                        "value": "cancelled",
-                        "name": "CANCELLED"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "FAILED"
+            "type": "enum",
+            "members": {
+                "SUBMITTED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "submitted"
                     }
-                ]
+                },
+                "MODIFYING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modifying"
+                    }
+                },
+                "ACTIVE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "PARTIALLY_FULFILLED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "partially_fulfilled"
+                    }
+                },
+                "EXPIRING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "expiring"
+                    }
+                },
+                "EXPIRED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "expired"
+                    }
+                },
+                "CANCELLING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelling"
+                    }
+                },
+                "CANCELLED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelled"
+                    }
+                },
+                "FAILED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#CapacityReservationGroup": {
@@ -7688,78 +8163,110 @@
             }
         },
         "com.amazonaws.ec2#CapacityReservationInstancePlatform": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Linux/UNIX",
-                        "name": "LINUX_UNIX"
-                    },
-                    {
-                        "value": "Red Hat Enterprise Linux",
-                        "name": "RED_HAT_ENTERPRISE_LINUX"
-                    },
-                    {
-                        "value": "SUSE Linux",
-                        "name": "SUSE_LINUX"
-                    },
-                    {
-                        "value": "Windows",
-                        "name": "WINDOWS"
-                    },
-                    {
-                        "value": "Windows with SQL Server",
-                        "name": "WINDOWS_WITH_SQL_SERVER"
-                    },
-                    {
-                        "value": "Windows with SQL Server Enterprise",
-                        "name": "WINDOWS_WITH_SQL_SERVER_ENTERPRISE"
-                    },
-                    {
-                        "value": "Windows with SQL Server Standard",
-                        "name": "WINDOWS_WITH_SQL_SERVER_STANDARD"
-                    },
-                    {
-                        "value": "Windows with SQL Server Web",
-                        "name": "WINDOWS_WITH_SQL_SERVER_WEB"
-                    },
-                    {
-                        "value": "Linux with SQL Server Standard",
-                        "name": "LINUX_WITH_SQL_SERVER_STANDARD"
-                    },
-                    {
-                        "value": "Linux with SQL Server Web",
-                        "name": "LINUX_WITH_SQL_SERVER_WEB"
-                    },
-                    {
-                        "value": "Linux with SQL Server Enterprise",
-                        "name": "LINUX_WITH_SQL_SERVER_ENTERPRISE"
-                    },
-                    {
-                        "value": "RHEL with SQL Server Standard",
-                        "name": "RHEL_WITH_SQL_SERVER_STANDARD"
-                    },
-                    {
-                        "value": "RHEL with SQL Server Enterprise",
-                        "name": "RHEL_WITH_SQL_SERVER_ENTERPRISE"
-                    },
-                    {
-                        "value": "RHEL with SQL Server Web",
-                        "name": "RHEL_WITH_SQL_SERVER_WEB"
-                    },
-                    {
-                        "value": "RHEL with HA",
-                        "name": "RHEL_WITH_HA"
-                    },
-                    {
-                        "value": "RHEL with HA and SQL Server Standard",
-                        "name": "RHEL_WITH_HA_AND_SQL_SERVER_STANDARD"
-                    },
-                    {
-                        "value": "RHEL with HA and SQL Server Enterprise",
-                        "name": "RHEL_WITH_HA_AND_SQL_SERVER_ENTERPRISE"
+            "type": "enum",
+            "members": {
+                "LINUX_UNIX": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Linux/UNIX"
                     }
-                ]
+                },
+                "RED_HAT_ENTERPRISE_LINUX": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Red Hat Enterprise Linux"
+                    }
+                },
+                "SUSE_LINUX": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "SUSE Linux"
+                    }
+                },
+                "WINDOWS": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Windows"
+                    }
+                },
+                "WINDOWS_WITH_SQL_SERVER": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Windows with SQL Server"
+                    }
+                },
+                "WINDOWS_WITH_SQL_SERVER_ENTERPRISE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Windows with SQL Server Enterprise"
+                    }
+                },
+                "WINDOWS_WITH_SQL_SERVER_STANDARD": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Windows with SQL Server Standard"
+                    }
+                },
+                "WINDOWS_WITH_SQL_SERVER_WEB": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Windows with SQL Server Web"
+                    }
+                },
+                "LINUX_WITH_SQL_SERVER_STANDARD": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Linux with SQL Server Standard"
+                    }
+                },
+                "LINUX_WITH_SQL_SERVER_WEB": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Linux with SQL Server Web"
+                    }
+                },
+                "LINUX_WITH_SQL_SERVER_ENTERPRISE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Linux with SQL Server Enterprise"
+                    }
+                },
+                "RHEL_WITH_SQL_SERVER_STANDARD": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "RHEL with SQL Server Standard"
+                    }
+                },
+                "RHEL_WITH_SQL_SERVER_ENTERPRISE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "RHEL with SQL Server Enterprise"
+                    }
+                },
+                "RHEL_WITH_SQL_SERVER_WEB": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "RHEL with SQL Server Web"
+                    }
+                },
+                "RHEL_WITH_HA": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "RHEL with HA"
+                    }
+                },
+                "RHEL_WITH_HA_AND_SQL_SERVER_STANDARD": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "RHEL with HA and SQL Server Standard"
+                    }
+                },
+                "RHEL_WITH_HA_AND_SQL_SERVER_ENTERPRISE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "RHEL with HA and SQL Server Enterprise"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#CapacityReservationOptions": {
@@ -7793,18 +8300,20 @@
             }
         },
         "com.amazonaws.ec2#CapacityReservationPreference": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "open",
-                        "name": "open"
-                    },
-                    {
-                        "value": "none",
-                        "name": "none"
+            "type": "enum",
+            "members": {
+                "open": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "open"
                     }
-                ]
+                },
+                "none": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "none"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#CapacityReservationSet": {
@@ -7861,30 +8370,38 @@
             }
         },
         "com.amazonaws.ec2#CapacityReservationState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "expired",
-                        "name": "expired"
-                    },
-                    {
-                        "value": "cancelled",
-                        "name": "cancelled"
-                    },
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
+            "type": "enum",
+            "members": {
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
                     }
-                ]
+                },
+                "expired": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "expired"
+                    }
+                },
+                "cancelled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelled"
+                    }
+                },
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#CapacityReservationTarget": {
@@ -7932,18 +8449,20 @@
             }
         },
         "com.amazonaws.ec2#CapacityReservationTenancy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "default",
-                        "name": "default"
-                    },
-                    {
-                        "value": "dedicated",
-                        "name": "dedicated"
+            "type": "enum",
+            "members": {
+                "default": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "default"
                     }
-                ]
+                },
+                "dedicated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "dedicated"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#CarrierGateway": {
@@ -8006,6 +8525,7 @@
         "com.amazonaws.ec2#CarrierGatewayMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -8022,26 +8542,32 @@
             }
         },
         "com.amazonaws.ec2#CarrierGatewayState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#CertificateAuthentication": {
@@ -8080,6 +8606,7 @@
                 "Message": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The plain-text authorization message for the prefix and account.</p>",
                         "smithy.api#required": {}
                     }
@@ -8087,6 +8614,7 @@
                 "Signature": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The signed authorization message for the prefix and account.</p>",
                         "smithy.api#required": {}
                     }
@@ -8128,6 +8656,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ClassicLinkDnsSupported",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether ClassicLink DNS support is enabled for the VPC.</p>",
                         "smithy.api#xmlName": "classicLinkDnsSupported"
                     }
@@ -8275,18 +8805,20 @@
             }
         },
         "com.amazonaws.ec2#ClientCertificateRevocationListStatusCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "active",
-                        "name": "active"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ClientConnectOptions": {
@@ -8295,6 +8827,8 @@
                 "Enabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether client connect options are enabled. The default is <code>false</code> (not enabled).</p>"
                     }
                 },
@@ -8316,6 +8850,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Enabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether client connect options are enabled.</p>",
                         "smithy.api#xmlName": "enabled"
                     }
@@ -8359,6 +8895,8 @@
                 "UploadSize": {
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the uploaded disk image, in GiB.</p>"
                     }
                 },
@@ -8379,6 +8917,8 @@
                 "Enabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Enable or disable a customizable text banner that will be displayed on\n\t\t\tAmazon Web Services provided clients when a VPN session is established.</p>\n\t\t       <p>Valid values: <code>true | false</code>\n         </p>\n\t\t       <p>Default value: <code>false</code>\n         </p>"
                     }
                 },
@@ -8400,6 +8940,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Enabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Current state of text banner feature.</p>\n\t\t       <p>Valid values: <code>true | false</code>\n         </p>",
                         "smithy.api#xmlName": "enabled"
                     }
@@ -8508,22 +9050,26 @@
             }
         },
         "com.amazonaws.ec2#ClientVpnAuthenticationType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "certificate-authentication",
-                        "name": "certificate_authentication"
-                    },
-                    {
-                        "value": "directory-service-authentication",
-                        "name": "directory_service_authentication"
-                    },
-                    {
-                        "value": "federated-authentication",
-                        "name": "federated_authentication"
+            "type": "enum",
+            "members": {
+                "certificate_authentication": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "certificate-authentication"
                     }
-                ]
+                },
+                "directory_service_authentication": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "directory-service-authentication"
+                    }
+                },
+                "federated_authentication": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "federated-authentication"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ClientVpnAuthorizationRuleStatus": {
@@ -8551,26 +9097,32 @@
             }
         },
         "com.amazonaws.ec2#ClientVpnAuthorizationRuleStatusCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "authorizing",
-                        "name": "authorizing"
-                    },
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
-                    },
-                    {
-                        "value": "revoking",
-                        "name": "revoking"
+            "type": "enum",
+            "members": {
+                "authorizing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "authorizing"
                     }
-                ]
+                },
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "revoking": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "revoking"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ClientVpnConnection": {
@@ -8727,26 +9279,32 @@
             }
         },
         "com.amazonaws.ec2#ClientVpnConnectionStatusCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "failed-to-terminate",
-                        "name": "failed_to_terminate"
-                    },
-                    {
-                        "value": "terminating",
-                        "name": "terminating"
-                    },
-                    {
-                        "value": "terminated",
-                        "name": "terminated"
+            "type": "enum",
+            "members": {
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
                     }
-                ]
+                },
+                "failed_to_terminate": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed-to-terminate"
+                    }
+                },
+                "terminating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "terminating"
+                    }
+                },
+                "terminated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "terminated"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ClientVpnEndpoint": {
@@ -8820,6 +9378,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SplitTunnel",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether split-tunnel is enabled in the Client VPN endpoint.</p>\n\t\t       <p>For information about split-tunnel VPN endpoints, see <a href=\"https://docs.aws.amazon.com/vpn/latest/clientvpn-admin/split-tunnel-vpn.html\">Split-Tunnel Client VPN endpoint</a> \n\t\t\tin the <i>Client VPN Administrator Guide</i>.</p>",
                         "smithy.api#xmlName": "splitTunnel"
                     }
@@ -8844,6 +9404,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpnPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The port number for the  Client VPN endpoint.</p>",
                         "smithy.api#xmlName": "vpnPort"
                     }
@@ -8927,6 +9489,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SessionTimeoutHours",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum VPN session duration time in hours.</p>\n\t\t       <p>Valid values: <code>8 | 10 | 12 | 24</code>\n         </p>\n\t\t       <p>Default value: <code>24</code>\n         </p>",
                         "smithy.api#xmlName": "sessionTimeoutHours"
                     }
@@ -8969,18 +9533,20 @@
             }
         },
         "com.amazonaws.ec2#ClientVpnEndpointAttributeStatusCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "applying",
-                        "name": "applying"
-                    },
-                    {
-                        "value": "applied",
-                        "name": "applied"
+            "type": "enum",
+            "members": {
+                "applying": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "applying"
                     }
-                ]
+                },
+                "applied": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "applied"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ClientVpnEndpointId": {
@@ -9020,26 +9586,32 @@
             }
         },
         "com.amazonaws.ec2#ClientVpnEndpointStatusCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending-associate",
-                        "name": "pending_associate"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "pending_associate": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending-associate"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ClientVpnRoute": {
@@ -9140,26 +9712,32 @@
             }
         },
         "com.amazonaws.ec2#ClientVpnRouteStatusCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "creating",
-                        "name": "creating"
-                    },
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
+            "type": "enum",
+            "members": {
+                "creating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "creating"
                     }
-                ]
+                },
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ClientVpnSecurityGroupIdSet": {
@@ -9181,6 +9759,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "LogEnabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Status of VPN tunnel logging feature. Default value is <code>False</code>.</p>\n        <p>Valid values: <code>True</code> | <code>False</code>\n         </p>",
                         "smithy.api#xmlName": "logEnabled"
                     }
@@ -9212,6 +9792,8 @@
                 "LogEnabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Enable or disable VPN tunnel logging feature. Default value is <code>False</code>.</p>\n        <p>Valid values: <code>True</code> | <code>False</code>\n         </p>"
                     }
                 },
@@ -9376,6 +9958,7 @@
         "com.amazonaws.ec2#CoipPoolMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -9409,6 +9992,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {}
                     }
@@ -9416,6 +10000,7 @@
                 "ProductCode": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The product code. This must be a product code that you own.</p>",
                         "smithy.api#required": {}
                     }
@@ -9424,6 +10009,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -9445,6 +10032,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>The return value of the request. Returns <code>true</code> if the specified product\n            code is owned by the requester and associated with the specified instance.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -9457,6 +10046,8 @@
                 "Enabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether connection logging is enabled.</p>"
                     }
                 },
@@ -9483,6 +10074,8 @@
                 "Enabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether client connection logging is enabled for the Client VPN endpoint.</p>"
                     }
                 },
@@ -9589,55 +10182,59 @@
             }
         },
         "com.amazonaws.ec2#ConnectionNotificationState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Enabled",
-                        "name": "Enabled"
-                    },
-                    {
-                        "value": "Disabled",
-                        "name": "Disabled"
+            "type": "enum",
+            "members": {
+                "Enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Enabled"
                     }
-                ]
+                },
+                "Disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Disabled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ConnectionNotificationType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Topic",
-                        "name": "Topic"
+            "type": "enum",
+            "members": {
+                "Topic": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Topic"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#ConnectivityType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "private",
-                        "name": "PRIVATE"
-                    },
-                    {
-                        "value": "public",
-                        "name": "PUBLIC"
+            "type": "enum",
+            "members": {
+                "PRIVATE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "private"
                     }
-                ]
+                },
+                "PUBLIC": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "public"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ContainerFormat": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ova",
-                        "name": "ova"
+            "type": "enum",
+            "members": {
+                "ova": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ova"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#ConversionIdStringList": {
@@ -9717,26 +10314,32 @@
             "type": "string"
         },
         "com.amazonaws.ec2#ConversionTaskState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "cancelling",
-                        "name": "cancelling"
-                    },
-                    {
-                        "value": "cancelled",
-                        "name": "cancelled"
-                    },
-                    {
-                        "value": "completed",
-                        "name": "completed"
+            "type": "enum",
+            "members": {
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
                     }
-                ]
+                },
+                "cancelling": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelling"
+                    }
+                },
+                "cancelled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelled"
+                    }
+                },
+                "completed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "completed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#CopyFpgaImage": {
@@ -9757,12 +10360,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "SourceFpgaImageId": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the source AFI.</p>",
                         "smithy.api#required": {}
                     }
@@ -9782,6 +10388,7 @@
                 "SourceRegion": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Region that contains the source AFI.</p>",
                         "smithy.api#required": {}
                     }
@@ -9838,6 +10445,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specifies whether the destination snapshots of the copied image should be encrypted.\n       You can encrypt a copy of an unencrypted snapshot, but you cannot create an unencrypted\n       copy of an encrypted snapshot. The default KMS key for Amazon EBS is used unless you specify a non-default \n       Key Management Service (KMS) KMS key using <code>KmsKeyId</code>. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSEncryption.html\">Amazon EBS Encryption</a> in the <i>Amazon Elastic Compute Cloud User Guide</i>.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -9853,6 +10462,7 @@
                 "Name": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The name of the new AMI in the destination Region.</p>",
                         "smithy.api#required": {}
                     }
@@ -9860,6 +10470,7 @@
                 "SourceImageId": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AMI to copy.</p>",
                         "smithy.api#required": {}
                     }
@@ -9867,6 +10478,7 @@
                 "SourceRegion": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The name of the Region that contains the AMI to copy.</p>",
                         "smithy.api#required": {}
                     }
@@ -9881,6 +10493,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -9945,6 +10559,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>To encrypt a copy of an unencrypted snapshot if encryption by default is not enabled, \n      enable encryption using this parameter. Otherwise, omit this parameter. Encrypted snapshots \n      are encrypted, even if you omit this parameter and encryption by default is not enabled. You \n      cannot set this parameter to false. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSEncryption.html\">Amazon EBS encryption</a> in the \n      <i>Amazon Elastic Compute Cloud User Guide</i>.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -9968,6 +10584,7 @@
                 "SourceRegion": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Region that contains the snapshot to be copied.</p>",
                         "smithy.api#required": {}
                     }
@@ -9975,6 +10592,7 @@
                 "SourceSnapshotId": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the EBS snapshot to copy.</p>",
                         "smithy.api#required": {}
                     }
@@ -9990,6 +10608,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -10018,21 +10638,18 @@
             }
         },
         "com.amazonaws.ec2#CopyTagsFromSource": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "volume",
-                        "name": "volume"
+            "type": "enum",
+            "members": {
+                "volume": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "volume"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#CoreCount": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#CoreCountList": {
             "type": "list",
@@ -10047,22 +10664,26 @@
             "type": "string"
         },
         "com.amazonaws.ec2#CpuManufacturer": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "intel",
-                        "name": "INTEL"
-                    },
-                    {
-                        "value": "amd",
-                        "name": "AMD"
-                    },
-                    {
-                        "value": "amazon-web-services",
-                        "name": "AMAZON_WEB_SERVICES"
+            "type": "enum",
+            "members": {
+                "INTEL": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "intel"
                     }
-                ]
+                },
+                "AMD": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "amd"
+                    }
+                },
+                "AMAZON_WEB_SERVICES": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "amazon-web-services"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#CpuManufacturerSet": {
@@ -10081,6 +10702,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "CoreCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of CPU cores for the instance.</p>",
                         "smithy.api#xmlName": "coreCount"
                     }
@@ -10089,6 +10712,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ThreadsPerCore",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of threads per CPU core.</p>",
                         "smithy.api#xmlName": "threadsPerCore"
                     }
@@ -10104,12 +10729,16 @@
                 "CoreCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of CPU cores for the instance.</p>"
                     }
                 },
                 "ThreadsPerCore": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of threads per CPU core. To disable multithreading for the instance,\n            specify a value of <code>1</code>. Otherwise, specify the default value of\n                <code>2</code>.</p>"
                     }
                 }
@@ -10161,6 +10790,7 @@
                 "InstanceTypeSpecifications": {
                     "target": "com.amazonaws.ec2#ReservationFleetInstanceSpecificationList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Information about the instance types for which to reserve the capacity.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "InstanceTypeSpecification"
@@ -10175,6 +10805,8 @@
                 "TotalTargetCapacity": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of capacity units to be reserved by the Capacity Reservation Fleet. This \n\t\t\tvalue, together with the instance type weights that you assign to each instance type used by \n\t\t\tthe Fleet determine the number of instances for which the Fleet reserves capacity. Both values \n\t\t\tare based on units that make sense for your workload. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/crfleet-concepts.html#target-capacity\">\n\t\t\t\tTotal target capacity</a> in the Amazon EC2 User Guide.</p>",
                         "smithy.api#required": {}
                     }
@@ -10201,6 +10833,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -10229,6 +10863,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalTargetCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of capacity units for which the Capacity Reservation Fleet reserves capacity.</p>",
                         "smithy.api#xmlName": "totalTargetCapacity"
                     }
@@ -10237,6 +10873,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalFulfilledCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The requested capacity units that have been successfully reserved.</p>",
                         "smithy.api#xmlName": "totalFulfilledCapacity"
                     }
@@ -10311,6 +10949,7 @@
                 "InstanceType": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The instance type for which to reserve capacity. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html\">Instance types</a> in the <i>Amazon EC2 User Guide</i>.</p>",
                         "smithy.api#required": {}
                     }
@@ -10318,6 +10957,7 @@
                 "InstancePlatform": {
                     "target": "com.amazonaws.ec2#CapacityReservationInstancePlatform",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The type of operating system for which to reserve capacity.</p>",
                         "smithy.api#required": {}
                     }
@@ -10343,6 +10983,8 @@
                 "InstanceCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of instances for which to reserve capacity.</p>\n\t  \t     <p>Valid range: 1 - 1000</p>",
                         "smithy.api#required": {}
                     }
@@ -10350,12 +10992,16 @@
                 "EbsOptimized": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the Capacity Reservation supports EBS-optimized instances. This optimization provides\n\t\t\tdedicated throughput to Amazon EBS and an optimized configuration stack to provide\n\t\t\toptimal I/O performance. This optimization isn't available with all instance types.\n\t\t\tAdditional usage charges apply when using an EBS- optimized instance.</p>"
                     }
                 },
                 "EphemeralStorage": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>\n            <i>Deprecated.</i>\n         </p>"
                     }
                 },
@@ -10386,6 +11032,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -10434,6 +11082,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC to associate with the carrier gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -10448,6 +11097,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -10491,6 +11142,7 @@
                 "ClientCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IPv4 address range, in CIDR notation, from which to assign client IP addresses. The address range cannot overlap with the local CIDR of the VPC in which the associated subnet is located, or the routes that you add manually. The address range cannot be changed after the Client VPN endpoint has been created. The CIDR block should be /22 or greater.</p>",
                         "smithy.api#required": {}
                     }
@@ -10498,6 +11150,7 @@
                 "ServerCertificateArn": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ARN of the server certificate. For more information, see \n\t\t\tthe <a href=\"https://docs.aws.amazon.com/acm/latest/userguide/\">Certificate Manager User Guide</a>.</p>",
                         "smithy.api#required": {}
                     }
@@ -10505,6 +11158,7 @@
                 "AuthenticationOptions": {
                     "target": "com.amazonaws.ec2#ClientVpnAuthenticationRequestList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Information about the authentication method to be used to authenticate clients.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "Authentication"
@@ -10513,6 +11167,7 @@
                 "ConnectionLogOptions": {
                     "target": "com.amazonaws.ec2#ConnectionLogOptions",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Information about the client connection logging options.</p>\n\t\t       <p>If you enable client connection logging, data about client connections is sent to a\n\t\t\tCloudwatch Logs log stream. The following information is logged:</p>\n\t\t       <ul>\n            <li>\n               <p>Client connection requests</p>\n            </li>\n            <li>\n               <p>Client connection results (successful and unsuccessful)</p>\n            </li>\n            <li>\n               <p>Reasons for unsuccessful client connection requests</p>\n            </li>\n            <li>\n               <p>Client connection termination time</p>\n            </li>\n         </ul>",
                         "smithy.api#required": {}
                     }
@@ -10532,6 +11187,8 @@
                 "VpnPort": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The port number to assign to the Client VPN endpoint for TCP and UDP traffic.</p>\n\t        <p>Valid Values: <code>443</code> | <code>1194</code>\n         </p>\n\t        <p>Default Value: <code>443</code>\n         </p>"
                     }
                 },
@@ -10544,12 +11201,16 @@
                 "SplitTunnel": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether split-tunnel is enabled on the Client VPN endpoint.</p>\n\t\t       <p>By default, split-tunnel on a VPN endpoint is disabled.</p>\n\t\t       <p>For information about split-tunnel VPN endpoints, see <a href=\"https://docs.aws.amazon.com/vpn/latest/clientvpn-admin/split-tunnel-vpn.html\">Split-tunnel Client VPN endpoint</a> in the \n\t\t\t<i>Client VPN Administrator Guide</i>.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -10595,6 +11256,8 @@
                 "SessionTimeoutHours": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum VPN session duration time in hours.</p>\n\t\t       <p>Valid values: <code>8 | 10 | 12 | 24</code>\n         </p>\n\t\t       <p>Default value: <code>24</code>\n         </p>"
                     }
                 },
@@ -10653,6 +11316,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint to which to add the route.</p>",
                         "smithy.api#required": {}
                     }
@@ -10660,6 +11324,7 @@
                 "DestinationCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IPv4 address range, in CIDR notation, of the route destination. For example:</p>\n\t\t       <ul>\n            <li>\n               <p>To add a route for Internet access, enter <code>0.0.0.0/0</code>\n               </p>\n            </li>\n            <li>\n               <p>To add a route for a peered VPC, enter the peered VPC's IPv4 CIDR range</p>\n            </li>\n            <li>\n               <p>To add a route for an on-premises network, enter the Amazon Web Services Site-to-Site VPN connection's IPv4 CIDR range</p>\n            </li>\n            <li>\n               <p>To add a route for the local network, enter the client CIDR range</p>\n            </li>\n         </ul>",
                         "smithy.api#required": {}
                     }
@@ -10667,6 +11332,7 @@
                 "TargetVpcSubnetId": {
                     "target": "com.amazonaws.ec2#SubnetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the subnet through which you want to route traffic. The specified subnet must be\n\t\t\tan existing target network of the Client VPN endpoint.</p>\n\t        <p>Alternatively, if you're adding a route for the local network, specify <code>local</code>.</p>",
                         "smithy.api#required": {}
                     }
@@ -10687,6 +11353,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -10723,6 +11391,7 @@
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>\n      A customer-owned IP address range to create.\n      </p>",
                         "smithy.api#required": {}
                     }
@@ -10730,6 +11399,7 @@
                 "CoipPoolId": {
                     "target": "com.amazonaws.ec2#Ipv4PoolCoipId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>\n         The ID of the address pool.\n      </p>",
                         "smithy.api#required": {}
                     }
@@ -10737,6 +11407,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -10773,6 +11445,7 @@
                 "LocalGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#LocalGatewayRoutetableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>\n      The ID of the local gateway route table.\n      </p>",
                         "smithy.api#required": {}
                     }
@@ -10787,6 +11460,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -10822,6 +11497,8 @@
                 "BgpAsn": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>For devices that support BGP, the customer gateway's BGP ASN.</p>\n        <p>Default: 65000</p>",
                         "smithy.api#required": {}
                     }
@@ -10841,6 +11518,7 @@
                 "Type": {
                     "target": "com.amazonaws.ec2#GatewayType",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The type of VPN connection that this customer gateway supports\n            (<code>ipsec.1</code>).</p>",
                         "smithy.api#required": {}
                     }
@@ -10868,6 +11546,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -10911,6 +11591,7 @@
                 "AvailabilityZone": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Availability Zone in which to create the default subnet.</p>",
                         "smithy.api#required": {}
                     }
@@ -10918,12 +11599,16 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "Ipv6Native": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to create an IPv6 only subnet. If you already have a default subnet\n            for this Availability Zone, you must delete it before you can create an IPv6 only subnet.</p>"
                     }
                 }
@@ -10960,6 +11645,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -10997,6 +11684,7 @@
                     "target": "com.amazonaws.ec2#NewDhcpConfigurationList",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DhcpConfiguration",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>A DHCP configuration option.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "dhcpConfiguration"
@@ -11013,6 +11701,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -11056,12 +11746,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC for which to create the egress-only internet gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -11220,6 +11913,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -11250,6 +11945,7 @@
                 "LaunchTemplateConfigs": {
                     "target": "com.amazonaws.ec2#FleetLaunchTemplateConfigListRequest",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The configuration for the EC2 Fleet.</p>",
                         "smithy.api#required": {}
                     }
@@ -11257,6 +11953,7 @@
                 "TargetCapacitySpecification": {
                     "target": "com.amazonaws.ec2#TargetCapacitySpecificationRequest",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The number of units to request.</p>",
                         "smithy.api#required": {}
                     }
@@ -11264,6 +11961,8 @@
                 "TerminateInstancesWithExpiration": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether running instances should be terminated when the EC2 Fleet expires.</p>"
                     }
                 },
@@ -11288,6 +11987,8 @@
                 "ReplaceUnhealthyInstances": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether EC2 Fleet should replace unhealthy Spot Instances. Supported only for\n         fleets of type <code>maintain</code>. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/manage-ec2-fleet.html#ec2-fleet-health-checks\">EC2 Fleet\n            health checks</a> in the <i>Amazon EC2 User Guide</i>.</p>"
                     }
                 },
@@ -11353,6 +12054,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -11383,6 +12086,7 @@
                 "ResourceIds": {
                     "target": "com.amazonaws.ec2#FlowLogResourceIds",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the resources to monitor. For example, if the resource type is\n                <code>VPC</code>, specify the IDs of the VPCs.</p>\n        <p>Constraints: Maximum of 1000 resources</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ResourceId"
@@ -11391,6 +12095,7 @@
                 "ResourceType": {
                     "target": "com.amazonaws.ec2#FlowLogsResourceType",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The type of resource to monitor.</p>",
                         "smithy.api#required": {}
                     }
@@ -11429,6 +12134,8 @@
                 "MaxAggregationInterval": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum interval of time during which a flow of packets is captured and aggregated into a flow log record. You can specify 60 seconds (1 minute) or 600 seconds (10 minutes).</p>\n        <p>When a network interface is attached to a <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html#ec2-nitro-instances\">Nitro-based\n                instance</a>, the aggregation interval is always 60 seconds or less, regardless\n            of the value that you specify.</p>\n        <p>Default: 600</p>"
                     }
                 },
@@ -11487,12 +12194,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "InputStorageLocation": {
                     "target": "com.amazonaws.ec2#StorageLocation",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The location of the encrypted design checkpoint in Amazon S3. The input must be a tarball.</p>",
                         "smithy.api#required": {}
                     }
@@ -11586,6 +12296,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -11594,6 +12306,7 @@
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "instanceId"
@@ -11603,6 +12316,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Name",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>A name for the new image.</p>\n         <p>Constraints: 3-128 alphanumeric characters, parentheses (()), square brackets ([]), spaces ( ), periods (.), slashes (/), dashes (-), single quotes ('), at-signs (@), or underscores(_)</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "name"
@@ -11612,6 +12326,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NoReboot",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>By default, when Amazon EC2 creates the new AMI, it reboots the instance so that it can \n\t\t\t\t\ttake snapshots of the attached volumes while data is at rest, in order to ensure a consistent \n\t\t\t\t\tstate. You can set the <code>NoReboot</code> parameter to <code>true</code> in the API request, \n\t\t\t\t\tor use the <code>--no-reboot</code> option in the CLI to prevent Amazon EC2 from shutting down and \n\t\t\t\t\trebooting the instance.</p>\n   \t     <important>\n\t\t\t\t\t       <p>If you choose to bypass the shutdown and reboot process by setting the <code>NoReboot</code> \n\t\t\t\t\tparameter to <code>true</code> in the API request, or by using the <code>--no-reboot</code> option \n\t\t\t\t\tin the CLI, we can't guarantee the file system integrity of the created image.</p>\n\t\t\t\t     </important>\n         <p>Default: <code>false</code> (follow standard reboot process)</p>",
                         "smithy.api#xmlName": "noReboot"
                     }
@@ -11656,6 +12372,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -11727,6 +12445,7 @@
                     "target": "com.amazonaws.ec2#ExportToS3TaskSpecification",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ExportToS3",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The format and location for an export instance task.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "exportToS3"
@@ -11736,6 +12455,7 @@
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "instanceId"
@@ -11745,6 +12465,7 @@
                     "target": "com.amazonaws.ec2#ExportEnvironment",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TargetEnvironment",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The target virtualization environment.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "targetEnvironment"
@@ -11798,6 +12519,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -11847,12 +12570,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamScopeId": {
                     "target": "com.amazonaws.ec2#IpamScopeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the scope in which you would like to create the IPAM pool.</p>",
                         "smithy.api#required": {}
                     }
@@ -11878,6 +12604,7 @@
                 "AddressFamily": {
                     "target": "com.amazonaws.ec2#AddressFamily",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IP protocol assigned to this IPAM pool. You must choose either IPv4 or IPv6 protocol for a pool.</p>",
                         "smithy.api#required": {}
                     }
@@ -11885,30 +12612,40 @@
                 "AutoImport": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If selected, IPAM will continuously look for resources within the CIDR range of this pool \n         and automatically import them as allocations into your IPAM. The CIDRs that will be allocated for\n         these resources must not already be allocated to other resources in order for the import to succeed. IPAM will import \n         a CIDR regardless of its compliance with the pool's allocation rules, so a resource might be imported and subsequently \n         marked as noncompliant. If IPAM discovers multiple CIDRs that overlap, IPAM will import the largest CIDR only. If IPAM \n         discovers multiple CIDRs with matching CIDRs, IPAM will randomly import one of them only.\n      </p>\n         <p>A locale must be set on the pool for this feature to work.</p>"
                     }
                 },
                 "PubliclyAdvertisable": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Determines if the pool is publicly advertisable. This option is not available for pools with AddressFamily set to <code>ipv4</code>.</p>"
                     }
                 },
                 "AllocationMinNetmaskLength": {
                     "target": "com.amazonaws.ec2#IpamNetmaskLength",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum netmask length required for CIDR allocations in this IPAM pool to be compliant. The minimum netmask length must be \n         less than the maximum netmask length. Possible netmask lengths for IPv4 addresses are 0 - 32. Possible netmask lengths for IPv6 addresses are  0 - 128.</p>"
                     }
                 },
                 "AllocationMaxNetmaskLength": {
                     "target": "com.amazonaws.ec2#IpamNetmaskLength",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum netmask length possible for CIDR allocations in this IPAM pool to be compliant. The maximum netmask length must be \n         greater than the minimum netmask length. Possible netmask lengths for IPv4 addresses are 0 - 32. Possible netmask lengths for IPv6 addresses are  0 - 128.</p>"
                     }
                 },
                 "AllocationDefaultNetmaskLength": {
                     "target": "com.amazonaws.ec2#IpamNetmaskLength",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The default netmask length for allocations added to this pool. If, for example, the CIDR assigned to this pool is 10.0.0.0/8 and you enter 16 here, \n         new allocations will default to 10.0.0.0/16.</p>"
                     }
                 },
@@ -11960,6 +12697,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -12023,12 +12762,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamId": {
                     "target": "com.amazonaws.ec2#IpamId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPAM for which you're creating this scope.</p>",
                         "smithy.api#required": {}
                     }
@@ -12086,6 +12828,7 @@
                 "KeyName": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>A unique name for the key pair.</p>\n\t        <p>Constraints: Up to 255 ASCII characters</p>",
                         "smithy.api#required": {}
                     }
@@ -12094,6 +12837,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -12137,6 +12882,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -12149,6 +12896,7 @@
                 "LaunchTemplateName": {
                     "target": "com.amazonaws.ec2#LaunchTemplateName",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>A name for the launch template.</p>",
                         "smithy.api#required": {}
                     }
@@ -12162,6 +12910,7 @@
                 "LaunchTemplateData": {
                     "target": "com.amazonaws.ec2#RequestLaunchTemplateData",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The information for the launch template.</p>",
                         "smithy.api#required": {}
                     }
@@ -12214,6 +12963,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -12250,6 +13001,7 @@
                 "LaunchTemplateData": {
                     "target": "com.amazonaws.ec2#RequestLaunchTemplateData",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The information for the launch template.</p>",
                         "smithy.api#required": {}
                     }
@@ -12295,6 +13047,7 @@
                 "DestinationCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR range used for destination matches. Routing decisions are based on \n        the most specific match.</p>",
                         "smithy.api#required": {}
                     }
@@ -12302,6 +13055,7 @@
                 "LocalGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#LocalGatewayRoutetableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the local gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -12315,6 +13069,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -12357,6 +13113,7 @@
                 "LocalGatewayId": {
                     "target": "com.amazonaws.ec2#LocalGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>\n      The ID of the local gateway. \n      </p>",
                         "smithy.api#required": {}
                     }
@@ -12377,6 +13134,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -12412,6 +13171,7 @@
                 "LocalGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#LocalGatewayRoutetableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>\n      The ID of the local gateway route table.\n      </p>",
                         "smithy.api#required": {}
                     }
@@ -12419,6 +13179,7 @@
                 "LocalGatewayVirtualInterfaceGroupId": {
                     "target": "com.amazonaws.ec2#LocalGatewayVirtualInterfaceGroupId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>\n      The ID of the local gateway route table virtual interface group association.\n      </p>",
                         "smithy.api#required": {}
                     }
@@ -12433,6 +13194,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -12468,6 +13231,7 @@
                 "LocalGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#LocalGatewayRoutetableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the local gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -12475,6 +13239,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {}
                     }
@@ -12489,6 +13254,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -12525,12 +13292,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "PrefixListName": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>A name for the prefix list.</p>\n        <p>Constraints: Up to 255 characters in length. The name cannot start with <code>com.amazonaws</code>.</p>",
                         "smithy.api#required": {}
                     }
@@ -12545,6 +13315,8 @@
                 "MaxEntries": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of entries for the prefix list.</p>",
                         "smithy.api#required": {}
                     }
@@ -12559,6 +13331,7 @@
                 "AddressFamily": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IP address type.</p>\n        <p>Valid Values: <code>IPv4</code> | <code>IPv6</code>\n         </p>",
                         "smithy.api#required": {}
                     }
@@ -12616,12 +13389,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "SubnetId": {
                     "target": "com.amazonaws.ec2#SubnetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The subnet in which to create the NAT gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -12701,6 +13477,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -12709,6 +13487,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Egress",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether this is an egress rule (rule is applied to traffic leaving the subnet).</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "egress"
@@ -12733,6 +13513,7 @@
                     "target": "com.amazonaws.ec2#NetworkAclId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkAclId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network ACL.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkAclId"
@@ -12750,6 +13531,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Protocol",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The protocol number. A value of \"-1\" means all protocols. If you specify \"-1\" or a\n  \t\t\tprotocol number other than \"6\" (TCP), \"17\" (UDP), or \"1\" (ICMP), traffic on all ports is \n\t\t\tallowed, regardless of any ports or ICMP types or codes that you specify. If you specify \n\t\t\tprotocol \"58\" (ICMPv6) and specify an IPv4 CIDR block, traffic for all ICMP types and \n\t\t\tcodes allowed, regardless of any that you specify. If you specify protocol \"58\" (ICMPv6) \n\t\t\tand specify an IPv6 CIDR block, you must specify an ICMP type and code.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "protocol"
@@ -12759,6 +13541,7 @@
                     "target": "com.amazonaws.ec2#RuleAction",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RuleAction",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Indicates whether to allow or deny the traffic that matches the rule.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ruleAction"
@@ -12768,6 +13551,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RuleNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The rule number for the entry (for example, 100). ACL entries are processed in ascending order by rule number.</p>\n         <p>Constraints: Positive integer from 1 to 32766. The range 32767 to 65535 is reserved for internal use.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ruleNumber"
@@ -12782,6 +13567,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -12790,6 +13577,7 @@
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcId"
@@ -12849,6 +13637,7 @@
                 "ClientToken": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Unique, case-sensitive identifier that you provide to ensure the idempotency of the request. For more information, \n   see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/Run_Instance_Idempotency.html\">How to ensure idempotency</a>.</p>",
                         "smithy.api#idempotencyToken": {},
                         "smithy.api#required": {}
@@ -12864,6 +13653,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -12920,6 +13711,7 @@
                 "Source": {
                     "target": "com.amazonaws.ec2#NetworkInsightsResourceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Amazon Web Services resource that is the source of the path.</p>",
                         "smithy.api#required": {}
                     }
@@ -12927,6 +13719,7 @@
                 "Destination": {
                     "target": "com.amazonaws.ec2#NetworkInsightsResourceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Amazon Web Services resource that is the destination of the path.</p>",
                         "smithy.api#required": {}
                     }
@@ -12934,6 +13727,7 @@
                 "Protocol": {
                     "target": "com.amazonaws.ec2#Protocol",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The protocol.</p>",
                         "smithy.api#required": {}
                     }
@@ -12941,6 +13735,8 @@
                 "DestinationPort": {
                     "target": "com.amazonaws.ec2#Port",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The destination port.</p>"
                     }
                 },
@@ -12954,12 +13750,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ClientToken": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Unique, case-sensitive identifier that you provide to ensure the idempotency of the request. For more information, \n   see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/Run_Instance_Idempotency.html\">How to ensure idempotency</a>.</p>",
                         "smithy.api#idempotencyToken": {},
                         "smithy.api#required": {}
@@ -13010,6 +13809,7 @@
                 "NetworkInterfaceId": {
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network interface.</p>",
                         "smithy.api#required": {}
                     }
@@ -13029,6 +13829,7 @@
                 "Permission": {
                     "target": "com.amazonaws.ec2#InterfacePermissionType",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The type of permission to grant.</p>",
                         "smithy.api#required": {}
                     }
@@ -13036,6 +13837,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n\t\t\tOtherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -13075,6 +13878,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n            and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n            Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -13090,6 +13895,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Ipv6AddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv6 addresses to assign to a network interface. Amazon EC2\n            automatically selects the IPv6 addresses from the subnet range. You can't use this\n            option if specifying specific IPv6 addresses. If your subnet has the <code>AssignIpv6AddressOnCreation</code> attribute set\n            to <code>true</code>, you can specify <code>0</code> to override this setting.</p>",
                         "smithy.api#xmlName": "ipv6AddressCount"
                     }
@@ -13122,6 +13929,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SecondaryPrivateIpAddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of secondary private IPv4 addresses to assign to a network interface. When\n            you specify a number of secondary IPv4 addresses, Amazon EC2 selects these IP addresses\n            within the subnet's IPv4 CIDR range. You can't specify this option and specify more than\n            one private IP address using <code>privateIpAddresses</code>.</p>\n        <p>The number of IP addresses you can assign to a network interface varies by instance\n            type. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-eni.html#AvailableIpPerENI\">IP Addresses Per ENI Per\n                Instance Type</a> in the <i>Amazon Virtual Private Cloud User Guide</i>.</p>",
                         "smithy.api#xmlName": "secondaryPrivateIpAddressCount"
                     }
@@ -13136,6 +13945,8 @@
                 "Ipv4PrefixCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv4 prefixes that Amazon Web Services automatically assigns to the network interface. You cannot use this option if you use the <code>Ipv4 Prefixes</code> option.</p>"
                     }
                 },
@@ -13149,6 +13960,8 @@
                 "Ipv6PrefixCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv6 prefixes that Amazon Web Services automatically assigns to the network interface. You cannot use this option if you use the <code>Ipv6Prefixes</code> option.</p>"
                     }
                 },
@@ -13162,6 +13975,7 @@
                     "target": "com.amazonaws.ec2#SubnetId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SubnetId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the subnet to associate with the network interface.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "subnetId"
@@ -13229,6 +14043,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -13252,6 +14068,8 @@
                 "PartitionCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of partitions. Valid only when <b>Strategy</b> is\n            set to <code>partition</code>.</p>"
                     }
                 },
@@ -13300,6 +14118,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -13343,6 +14163,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance for which to replace the root volume.</p>",
                         "smithy.api#required": {}
                     }
@@ -13363,6 +14184,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -13407,6 +14230,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ClientToken",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Unique, case-sensitive identifier you provide to ensure idempotency of your\n\t\t\t\tlistings. This helps avoid duplicate listings. For more information, see \n\t\t\t\t<a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/Run_Instance_Idempotency.html\">Ensuring Idempotency</a>.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "clientToken"
@@ -13416,6 +14240,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of instances that are a part of a Reserved Instance account to be listed in the Reserved Instance Marketplace. This number should be less than or equal to the instance count associated with the Reserved Instance ID specified in this call.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "instanceCount"
@@ -13425,6 +14251,7 @@
                     "target": "com.amazonaws.ec2#PriceScheduleSpecificationList",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PriceSchedules",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>A list specifying the price of the Standard Reserved Instance for each month remaining in the Reserved Instance term.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "priceSchedules"
@@ -13434,6 +14261,7 @@
                     "target": "com.amazonaws.ec2#ReservationId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ReservedInstancesId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the active Standard Reserved Instance.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "reservedInstancesId"
@@ -13478,6 +14306,7 @@
                 "Bucket": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The name of the Amazon S3 bucket that contains the stored AMI object.</p>",
                         "smithy.api#required": {}
                     }
@@ -13485,6 +14314,7 @@
                 "ObjectKey": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The name of the stored AMI object in the bucket.</p>",
                         "smithy.api#required": {}
                     }
@@ -13505,6 +14335,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -13564,6 +14396,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -13636,6 +14470,7 @@
                     "target": "com.amazonaws.ec2#RouteTableId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RouteTableId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the route table for the route.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "routeTableId"
@@ -13664,6 +14499,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -13689,6 +14526,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -13697,6 +14536,7 @@
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcId"
@@ -13742,6 +14582,7 @@
                 "Description": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>A description for the security group. This is informational only.</p>\n\t\t       <p>Constraints: Up to 255 characters in length</p>\n\t\t       <p>Constraints for EC2-Classic: ASCII characters</p>\n\t\t       <p>Constraints for EC2-VPC: a-z, A-Z, 0-9, spaces, and ._-:/()#,@[]+=&;{}!$*</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "GroupDescription"
@@ -13750,6 +14591,7 @@
                 "GroupName": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The name of the security group.</p>\n         <p>Constraints: Up to 255 characters in length. Cannot start with\n            <code>sg-</code>.</p>\n         <p>Constraints for EC2-Classic: ASCII characters</p>\n         <p>Constraints for EC2-VPC: a-z, A-Z, 0-9, spaces, and ._-:/()#,@[]+=&;{}!$*</p>",
                         "smithy.api#required": {}
                     }
@@ -13771,6 +14613,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -13828,6 +14672,7 @@
                 "VolumeId": {
                     "target": "com.amazonaws.ec2#VolumeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Amazon EBS volume.</p>",
                         "smithy.api#required": {}
                     }
@@ -13843,6 +14688,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -13873,6 +14720,7 @@
                 "InstanceSpecification": {
                     "target": "com.amazonaws.ec2#InstanceSpecification",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The instance to specify which volumes should be included in the snapshots.</p>",
                         "smithy.api#required": {}
                     }
@@ -13893,6 +14741,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -13936,6 +14786,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Bucket",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The name of the Amazon S3 bucket in which to store the Spot Instance data feed. For\n            more information about bucket names, see <a href=\"https://docs.aws.amazon.com/AmazonS3/latest/dev/BucketRestrictions.html#bucketnamingrules\">Rules for bucket\n                naming</a> in the <i>Amazon S3 Developer Guide</i>.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "bucket"
@@ -13945,6 +14796,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -13996,6 +14849,7 @@
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AMI.</p>",
                         "smithy.api#required": {}
                     }
@@ -14003,6 +14857,7 @@
                 "Bucket": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The name of the Amazon S3 bucket in which the AMI object will be stored. The bucket must be in\n      the Region in which the request is being made. The AMI object appears in the bucket only after\n      the upload task has completed. </p>",
                         "smithy.api#required": {}
                     }
@@ -14017,6 +14872,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -14065,6 +14922,7 @@
                 "SubnetId": {
                     "target": "com.amazonaws.ec2#SubnetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the subnet.</p>",
                         "smithy.api#required": {}
                     }
@@ -14072,6 +14930,7 @@
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IPv4 or IPV6 CIDR range to reserve.</p>",
                         "smithy.api#required": {}
                     }
@@ -14079,6 +14938,7 @@
                 "ReservationType": {
                     "target": "com.amazonaws.ec2#SubnetCidrReservationType",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The type of reservation.</p>\n        <p>The following are valid values:</p>\n        <ul>\n            <li>\n                <p>\n                  <code>prefix</code>: The Amazon EC2\n                    Prefix\n                    Delegation feature assigns the IP addresses to network interfaces that are\n                    associated with an instance. For information about Prefix\n                    Delegation,\n                    see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-prefix-delegation.html\">Prefix Delegation\n                        for Amazon EC2 network interfaces</a> in the\n                        <i>Amazon Elastic Compute Cloud User Guide</i>.</p>\n            </li>\n            <li>\n                <p>\n                  <code>explicit</code>: You manually assign the IP addresses to resources that\n                    reside in your subnet. </p>\n            </li>\n         </ul>",
                         "smithy.api#required": {}
                     }
@@ -14092,6 +14952,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -14160,6 +15022,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {}
                     }
@@ -14168,6 +15031,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -14175,6 +15040,8 @@
                 "Ipv6Native": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to create an IPv6 only subnet.</p>"
                     }
                 }
@@ -14212,6 +15079,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -14219,6 +15088,7 @@
                 "Resources": {
                     "target": "com.amazonaws.ec2#ResourceIdList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the resources, separated by spaces.</p>\n   \t     <p>Constraints: Up to 1000 resource IDs. We recommend breaking up this request into smaller batches.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ResourceId"
@@ -14227,6 +15097,7 @@
                 "Tags": {
                     "target": "com.amazonaws.ec2#TagList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The tags. The <code>value</code> parameter is required, but if you don't want the tag to have a value,\n        specify the parameter with no value, and we set the value to an empty string.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "Tag"
@@ -14265,6 +15136,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -14316,6 +15189,7 @@
                 "TrafficMirrorFilterId": {
                     "target": "com.amazonaws.ec2#TrafficMirrorFilterId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the filter that this rule is associated with.</p>",
                         "smithy.api#required": {}
                     }
@@ -14323,6 +15197,7 @@
                 "TrafficDirection": {
                     "target": "com.amazonaws.ec2#TrafficDirection",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The type of traffic.</p>",
                         "smithy.api#required": {}
                     }
@@ -14330,6 +15205,8 @@
                 "RuleNumber": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of the Traffic Mirror rule. This number must be unique for each Traffic Mirror rule in a given\n         direction. The rules are processed in ascending order by rule number.</p>",
                         "smithy.api#required": {}
                     }
@@ -14337,6 +15214,7 @@
                 "RuleAction": {
                     "target": "com.amazonaws.ec2#TrafficMirrorRuleAction",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The action to take on the filtered traffic.</p>",
                         "smithy.api#required": {}
                     }
@@ -14356,12 +15234,15 @@
                 "Protocol": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The protocol, for example UDP, to assign to the Traffic Mirror rule.</p>\n         <p>For information about the protocol value, see <a href=\"https://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml\">Protocol Numbers</a> on the  Internet Assigned Numbers Authority (IANA) website.</p>"
                     }
                 },
                 "DestinationCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The destination CIDR block to assign to the Traffic Mirror rule.</p>",
                         "smithy.api#required": {}
                     }
@@ -14369,6 +15250,7 @@
                 "SourceCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The source CIDR block to assign to the Traffic Mirror rule.</p>",
                         "smithy.api#required": {}
                     }
@@ -14382,6 +15264,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -14433,6 +15317,7 @@
                 "NetworkInterfaceId": {
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the source network interface.</p>",
                         "smithy.api#required": {}
                     }
@@ -14440,6 +15325,7 @@
                 "TrafficMirrorTargetId": {
                     "target": "com.amazonaws.ec2#TrafficMirrorTargetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Traffic Mirror target.</p>",
                         "smithy.api#required": {}
                     }
@@ -14447,6 +15333,7 @@
                 "TrafficMirrorFilterId": {
                     "target": "com.amazonaws.ec2#TrafficMirrorFilterId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Traffic Mirror filter.</p>",
                         "smithy.api#required": {}
                     }
@@ -14454,12 +15341,16 @@
                 "PacketLength": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of bytes in each packet to mirror. These are bytes after the VXLAN header. Do\n         not specify this parameter when you want to mirror the entire packet. To mirror a subset of\n         the packet, set this to the length (in bytes) that you want to mirror. For example, if you\n         set this value to 100, then the first 100 bytes that meet the filter criteria are copied to\n         the target.</p>\n         <p>If you do not want to mirror the entire packet, use the <code>PacketLength</code> parameter to specify the number of bytes in each packet to mirror.</p>"
                     }
                 },
                 "SessionNumber": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The session number determines the order in which sessions are evaluated when an interface is used by multiple sessions. The first session with a matching filter is the one that mirrors the packets.</p>\n         <p>Valid values are 1-32766.</p>",
                         "smithy.api#required": {}
                     }
@@ -14467,6 +15358,8 @@
                 "VirtualNetworkId": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The VXLAN ID for the Traffic Mirror session. For more information about the VXLAN\n         protocol, see <a href=\"https://tools.ietf.org/html/rfc7348\">RFC 7348</a>. If you do\n         not specify a <code>VirtualNetworkId</code>, an account-wide unique id is chosen at\n         random.</p>"
                     }
                 },
@@ -14486,6 +15379,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -14562,6 +15457,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -14643,6 +15540,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Connect attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -14656,6 +15554,7 @@
                 "PeerAddress": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The peer IP address (GRE outer IP address) on the appliance side of the Connect peer.</p>",
                         "smithy.api#required": {}
                     }
@@ -14669,6 +15568,7 @@
                 "InsideCidrBlocks": {
                     "target": "com.amazonaws.ec2#InsideCidrBlocksStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The range of inside IP addresses that are used for BGP peering. You must specify a\n            size /29 IPv4 CIDR block from the <code>169.254.0.0/16</code> range. The first address\n            from the range must be configured on the appliance as the BGP IP address. You can also\n            optionally specify a size /125 IPv6 CIDR block from the <code>fd00::/8</code>\n            range.</p>",
                         "smithy.api#required": {}
                     }
@@ -14683,6 +15583,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -14707,6 +15609,7 @@
                 "TransportTransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway attachment. You can specify a VPC attachment or Amazon Web Services Direct Connect attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -14714,6 +15617,7 @@
                 "Options": {
                     "target": "com.amazonaws.ec2#CreateTransitGatewayConnectRequestOptions",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Connect attachment options.</p>",
                         "smithy.api#required": {}
                     }
@@ -14728,6 +15632,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -14739,6 +15645,7 @@
                 "Protocol": {
                     "target": "com.amazonaws.ec2#ProtocolValue",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The tunnel protocol.</p>",
                         "smithy.api#required": {}
                     }
@@ -14779,6 +15686,7 @@
                 "TransitGatewayId": {
                     "target": "com.amazonaws.ec2#TransitGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -14799,6 +15707,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -14861,6 +15771,7 @@
                 "TransitGatewayId": {
                     "target": "com.amazonaws.ec2#TransitGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -14868,6 +15779,7 @@
                 "PeerTransitGatewayId": {
                     "target": "com.amazonaws.ec2#TransitAssociationGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the peer transit gateway with which to create the peering attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -14875,6 +15787,7 @@
                 "PeerAccountId": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Amazon Web Services account that owns the peer transit gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -14882,6 +15795,7 @@
                 "PeerRegion": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Region where the peer transit gateway is located.</p>",
                         "smithy.api#required": {}
                     }
@@ -14902,6 +15816,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -14952,6 +15868,7 @@
                 "TransitGatewayId": {
                     "target": "com.amazonaws.ec2#TransitGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway used for the policy table.</p>",
                         "smithy.api#required": {}
                     }
@@ -14965,6 +15882,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -15001,6 +15920,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -15008,6 +15928,7 @@
                 "PrefixListId": {
                     "target": "com.amazonaws.ec2#PrefixListResourceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the prefix list that is used for destination matches.</p>",
                         "smithy.api#required": {}
                     }
@@ -15021,12 +15942,16 @@
                 "Blackhole": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to drop traffic that matches this route.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -15070,6 +15995,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -15106,6 +16033,7 @@
                 "DestinationCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR range used for destination matches. Routing decisions are based on the\n         most specific match.</p>",
                         "smithy.api#required": {}
                     }
@@ -15113,6 +16041,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -15126,12 +16055,16 @@
                 "Blackhole": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to drop traffic that matches this route.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -15180,6 +16113,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -15187,6 +16121,7 @@
                 "PeeringAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the peering attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -15201,6 +16136,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -15225,6 +16162,7 @@
                 "TransitGatewayId": {
                     "target": "com.amazonaws.ec2#TransitGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -15238,6 +16176,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -15274,6 +16214,7 @@
                 "TransitGatewayId": {
                     "target": "com.amazonaws.ec2#TransitGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -15281,6 +16222,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {}
                     }
@@ -15288,6 +16230,7 @@
                 "SubnetIds": {
                     "target": "com.amazonaws.ec2#TransitGatewaySubnetIdList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of one or more subnets. You can specify only one subnet per Availability Zone. \n         You must specify at least one subnet, but we recommend that you specify two subnets for better availability.\n         The transit gateway uses one IP address from each specified subnet.</p>",
                         "smithy.api#required": {}
                     }
@@ -15307,6 +16250,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -15422,6 +16367,7 @@
                 "AvailabilityZone": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Availability Zone in which to create the volume.</p>",
                         "smithy.api#required": {}
                     }
@@ -15430,6 +16376,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the volume should be encrypted. \n      The effect of setting the encryption state to <code>true</code> depends on \nthe volume origin (new or from a snapshot), starting encryption state, ownership, and whether encryption by default is enabled. \n      For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSEncryption.html#encryption-by-default\">Encryption by default</a>\n      in the <i>Amazon Elastic Compute Cloud User Guide</i>.</p>\n         <p>Encrypted Amazon EBS volumes must be attached to instances that support Amazon EBS encryption. \n      For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSEncryption.html#EBSEncryption_supported_instances\">Supported\n        instance types</a>.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -15437,6 +16385,8 @@
                 "Iops": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of I/O operations per second (IOPS). For <code>gp3</code>, <code>io1</code>, and <code>io2</code> volumes, this represents \n      the number of IOPS that are provisioned for the volume. For <code>gp2</code> volumes, this represents the baseline \n      performance of the volume and the rate at which the volume accumulates I/O credits for bursting.</p>\n         <p>The following are the supported values for each volume type:</p>\n         <ul>\n            <li>\n               <p>\n                  <code>gp3</code>: 3,000-16,000 IOPS</p>\n            </li>\n            <li>\n               <p>\n                  <code>io1</code>: 100-64,000 IOPS</p>\n            </li>\n            <li>\n               <p>\n                  <code>io2</code>: 100-64,000 IOPS</p>\n            </li>\n         </ul>\n         <p>\n            <code>io1</code> and <code>io2</code> volumes support up to 64,000 IOPS only on  \n      <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html#ec2-nitro-instances\">Instances built on the Nitro System</a>. Other instance families support performance \n      up to 32,000 IOPS.</p>\n         <p>This parameter is required for <code>io1</code> and <code>io2</code> volumes.\n      The default for <code>gp3</code> volumes is 3,000 IOPS.\n      This parameter is not supported for <code>gp2</code>, <code>st1</code>, <code>sc1</code>, or <code>standard</code> volumes.</p>"
                     }
                 },
@@ -15455,6 +16405,8 @@
                 "Size": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the volume, in GiBs. You must specify either a snapshot ID or a volume size.\n      If you specify a snapshot, the default is the snapshot size. You can specify a volume \n      size that is equal to or larger than the snapshot size.</p>\n         <p>The following are the supported volumes sizes for each volume type:</p>\n         <ul>\n            <li>\n               <p>\n                  <code>gp2</code> and <code>gp3</code>: 1-16,384</p>\n            </li>\n            <li>\n               <p>\n                  <code>io1</code> and <code>io2</code>: 4-16,384</p>\n            </li>\n            <li>\n               <p>\n                  <code>st1</code> and <code>sc1</code>: 125-16,384</p>\n            </li>\n            <li>\n               <p>\n                  <code>standard</code>: 1-1,024</p>\n            </li>\n         </ul>"
                     }
                 },
@@ -15474,6 +16426,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -15488,12 +16442,16 @@
                 "MultiAttachEnabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to enable Amazon EBS Multi-Attach. If you enable Multi-Attach, you can attach the \n    \tvolume to up to 16 <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html#ec2-nitro-instances\">Instances built on the Nitro System</a> in the same Availability Zone. This parameter is \n    \tsupported with <code>io1</code> and <code>io2</code> volumes only. For more information, \n    \tsee <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-volumes-multi.html\">\n    \t\tAmazon EBS Multi-Attach</a> in the <i>Amazon Elastic Compute Cloud User Guide</i>.</p>"
                     }
                 },
                 "Throughput": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The throughput to provision for a volume, with a maximum of 1,000 MiB/s.</p>\n         <p>This parameter is valid only for <code>gp3</code> volumes.</p>\n  \t      <p>Valid Range: Minimum value of 125. Maximum value of 1000.</p>"
                     }
                 },
@@ -15548,6 +16506,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -15566,6 +16526,7 @@
                 "ConnectionNotificationArn": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ARN of the SNS topic for the notifications.</p>",
                         "smithy.api#required": {}
                     }
@@ -15573,6 +16534,7 @@
                 "ConnectionEvents": {
                     "target": "com.amazonaws.ec2#ValueStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>One or more endpoint events for which to receive notifications. Valid values are\n                <code>Accept</code>, <code>Connect</code>, <code>Delete</code>, and\n                <code>Reject</code>.</p>",
                         "smithy.api#required": {}
                     }
@@ -15612,6 +16574,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -15624,6 +16588,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC in which the endpoint will be used.</p>",
                         "smithy.api#required": {}
                     }
@@ -15631,6 +16596,7 @@
                 "ServiceName": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The service name. To get a list of available services, use the <a>DescribeVpcEndpointServices</a> request, or get the name from the service\n            provider.</p>",
                         "smithy.api#required": {}
                     }
@@ -15683,6 +16649,8 @@
                 "PrivateDnsEnabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>(Interface endpoint) Indicates whether to associate a private hosted zone with the\n            specified VPC. The private hosted zone contains a record set for the default public DNS\n            name for the service for the Region (for example,\n                <code>kinesis.us-east-1.amazonaws.com</code>), which resolves to the private IP\n            addresses of the endpoint network interfaces in the VPC. This enables you to make\n            requests to the default public DNS name for the service instead of the public DNS names\n            that are automatically generated by the VPC endpoint service.</p>\n        <p>To use a private hosted zone, you must set the following VPC attributes to\n            <code>true</code>: <code>enableDnsHostnames</code> and\n            <code>enableDnsSupport</code>. Use <a>ModifyVpcAttribute</a> to set the VPC\n            attributes.</p>\n        <p>Default: <code>true</code>\n         </p>"
                     }
                 },
@@ -15740,12 +16708,16 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "AcceptanceRequired": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether requests from service consumers to create an endpoint to your service must\n            be accepted manually.</p>"
                     }
                 },
@@ -15831,6 +16803,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -15900,6 +16874,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AmazonProvidedIpv6CidrBlock",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Requests an Amazon-provided IPv6 CIDR block with a /56 prefix length for the VPC.\n            You cannot specify the range of IP addresses, or the size of the CIDR block.</p>",
                         "smithy.api#xmlName": "amazonProvidedIpv6CidrBlock"
                     }
@@ -15944,6 +16920,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -16002,6 +16980,7 @@
                 "CustomerGatewayId": {
                     "target": "com.amazonaws.ec2#CustomerGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the customer gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -16009,6 +16988,7 @@
                 "Type": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The type of VPN connection (<code>ipsec.1</code>).</p>",
                         "smithy.api#required": {}
                     }
@@ -16029,6 +17009,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -16087,6 +17069,7 @@
                 "DestinationCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR block associated with the local subnet of the customer network.</p>",
                         "smithy.api#required": {}
                     }
@@ -16094,6 +17077,7 @@
                 "VpnConnectionId": {
                     "target": "com.amazonaws.ec2#VpnConnectionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPN connection.</p>",
                         "smithy.api#required": {}
                     }
@@ -16127,6 +17111,7 @@
                 "Type": {
                     "target": "com.amazonaws.ec2#GatewayType",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The type of VPN connection this virtual private gateway supports.</p>",
                         "smithy.api#required": {}
                     }
@@ -16141,6 +17126,8 @@
                 "AmazonSideAsn": {
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>A private Autonomous System Number (ASN) for the Amazon side of a BGP session. If\n            you're using a 16-bit ASN, it must be in the 64512 to 65534 range. If you're using a\n            32-bit ASN, it must be in the 4200000000 to 4294967294 range.</p>\n        <p>Default: 64512</p>"
                     }
                 },
@@ -16148,6 +17135,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -16195,6 +17184,7 @@
                 "CpuCredits": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The credit option for CPU usage of a T instance.</p>\n        <p>Valid values: <code>standard</code> | <code>unlimited</code>\n         </p>",
                         "smithy.api#required": {}
                     }
@@ -16205,21 +17195,18 @@
             }
         },
         "com.amazonaws.ec2#CurrencyCodeValues": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "USD",
-                        "name": "USD"
+            "type": "enum",
+            "members": {
+                "USD": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "USD"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#CurrentGenerationFlag": {
-            "type": "boolean",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "boolean"
         },
         "com.amazonaws.ec2#CustomerGateway": {
             "type": "structure",
@@ -16317,7 +17304,6 @@
         "com.amazonaws.ec2#DITMaxResults": {
             "type": "integer",
             "traits": {
-                "smithy.api#box": {},
                 "smithy.api#range": {
                     "min": 5,
                     "max": 100
@@ -16327,7 +17313,6 @@
         "com.amazonaws.ec2#DITOMaxResults": {
             "type": "integer",
             "traits": {
-                "smithy.api#box": {},
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -16335,28 +17320,27 @@
             }
         },
         "com.amazonaws.ec2#DatafeedSubscriptionState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Active",
-                        "name": "Active"
-                    },
-                    {
-                        "value": "Inactive",
-                        "name": "Inactive"
+            "type": "enum",
+            "members": {
+                "Active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Active"
                     }
-                ]
+                },
+                "Inactive": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Inactive"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DateTime": {
             "type": "timestamp"
         },
         "com.amazonaws.ec2#DedicatedHostFlag": {
-            "type": "boolean",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "boolean"
         },
         "com.amazonaws.ec2#DedicatedHostId": {
             "type": "string"
@@ -16371,54 +17355,57 @@
             }
         },
         "com.amazonaws.ec2#DefaultNetworkCardIndex": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#DefaultRouteTableAssociationValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DefaultRouteTablePropagationValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DefaultTargetCapacityType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "spot",
-                        "name": "SPOT"
-                    },
-                    {
-                        "value": "on-demand",
-                        "name": "ON_DEMAND"
+            "type": "enum",
+            "members": {
+                "SPOT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "spot"
                     }
-                ]
+                },
+                "ON_DEMAND": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "on-demand"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DefaultingDhcpOptionsId": {
@@ -16442,6 +17429,7 @@
                 "CarrierGatewayId": {
                     "target": "com.amazonaws.ec2#CarrierGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the carrier gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -16449,6 +17437,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -16485,6 +17475,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN to be deleted.</p>",
                         "smithy.api#required": {}
                     }
@@ -16492,6 +17483,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -16528,6 +17521,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint from which the route is to be deleted.</p>",
                         "smithy.api#required": {}
                     }
@@ -16541,6 +17535,7 @@
                 "DestinationCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IPv4 address range, in CIDR notation, of the route to be deleted.</p>",
                         "smithy.api#required": {}
                     }
@@ -16548,6 +17543,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -16584,6 +17581,7 @@
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p> A customer-owned IP address range that you want to delete. </p>",
                         "smithy.api#required": {}
                     }
@@ -16591,6 +17589,7 @@
                 "CoipPoolId": {
                     "target": "com.amazonaws.ec2#Ipv4PoolCoipId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>\n        The ID of the customer-owned address pool. \n      </p>",
                         "smithy.api#required": {}
                     }
@@ -16598,6 +17597,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -16634,6 +17635,7 @@
                 "CoipPoolId": {
                     "target": "com.amazonaws.ec2#Ipv4PoolCoipId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the CoIP pool that you want to delete. </p>",
                         "smithy.api#required": {}
                     }
@@ -16641,6 +17643,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -16676,6 +17680,7 @@
                 "CustomerGatewayId": {
                     "target": "com.amazonaws.ec2#CustomerGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the customer gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -16684,6 +17689,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -16711,6 +17718,7 @@
                 "DhcpOptionsId": {
                     "target": "com.amazonaws.ec2#DhcpOptionsId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the DHCP options set.</p>",
                         "smithy.api#required": {}
                     }
@@ -16719,6 +17727,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -16743,12 +17753,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "EgressOnlyInternetGatewayId": {
                     "target": "com.amazonaws.ec2#EgressOnlyInternetGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the egress-only internet gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -16762,6 +17775,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ReturnCode",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "returnCode"
                     }
@@ -16793,26 +17808,32 @@
             }
         },
         "com.amazonaws.ec2#DeleteFleetErrorCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "fleetIdDoesNotExist",
-                        "name": "FLEET_ID_DOES_NOT_EXIST"
-                    },
-                    {
-                        "value": "fleetIdMalformed",
-                        "name": "FLEET_ID_MALFORMED"
-                    },
-                    {
-                        "value": "fleetNotInDeletableState",
-                        "name": "FLEET_NOT_IN_DELETABLE_STATE"
-                    },
-                    {
-                        "value": "unexpectedError",
-                        "name": "UNEXPECTED_ERROR"
+            "type": "enum",
+            "members": {
+                "FLEET_ID_DOES_NOT_EXIST": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fleetIdDoesNotExist"
                     }
-                ]
+                },
+                "FLEET_ID_MALFORMED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fleetIdMalformed"
+                    }
+                },
+                "FLEET_NOT_IN_DELETABLE_STATE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fleetNotInDeletableState"
+                    }
+                },
+                "UNEXPECTED_ERROR": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unexpectedError"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DeleteFleetErrorItem": {
@@ -16907,12 +17928,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "FleetIds": {
                     "target": "com.amazonaws.ec2#FleetIdSet",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the EC2 Fleets.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "FleetId"
@@ -16921,6 +17945,8 @@
                 "TerminateInstances": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to terminate the instances when the EC2 Fleet is deleted. The default is to\n         terminate the instances.</p>\n         <p>To let the instances continue to run after the EC2 Fleet is deleted, specify\n            <code>NoTerminateInstances</code>. Supported only for fleets of type\n            <code>maintain</code> and <code>request</code>.</p>\n         <p>For <code>instant</code> fleets, you cannot specify <code>NoTerminateInstances</code>. A\n         deleted <code>instant</code> fleet with running instances is not supported.</p>",
                         "smithy.api#required": {}
                     }
@@ -16966,12 +17992,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "FlowLogIds": {
                     "target": "com.amazonaws.ec2#FlowLogIdList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>One or more flow log IDs.</p>\n        <p>Constraint: Maximum of 1000 flow log IDs.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "FlowLogId"
@@ -17010,12 +18039,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "FpgaImageId": {
                     "target": "com.amazonaws.ec2#FpgaImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AFI.</p>",
                         "smithy.api#required": {}
                     }
@@ -17029,6 +18061,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Is <code>true</code> if the request succeeds, and an error otherwise.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -17053,18 +18087,23 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ForceDelete": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specify <code>true</code> to force delete the event window. Use the force delete parameter\n         if the event window is currently associated with targets.</p>"
                     }
                 },
                 "InstanceEventWindowId": {
                     "target": "com.amazonaws.ec2#InstanceEventWindowId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the event window.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "InstanceEventWindowId"
@@ -17104,6 +18143,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -17112,6 +18153,7 @@
                     "target": "com.amazonaws.ec2#InternetGatewayId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InternetGatewayId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the internet gateway.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "internetGatewayId"
@@ -17149,12 +18191,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamPoolId": {
                     "target": "com.amazonaws.ec2#IpamPoolId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the pool to delete.</p>",
                         "smithy.api#required": {}
                     }
@@ -17180,12 +18225,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamId": {
                     "target": "com.amazonaws.ec2#IpamId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPAM to delete.</p>",
                         "smithy.api#required": {}
                     }
@@ -17193,6 +18241,8 @@
                 "Cascade": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Enables you to quickly delete an IPAM, private scopes, pools in private scopes, and\n         any allocations in the pools in private scopes. You cannot delete the IPAM with this option if there is a pool in your public scope. If you use this option, IPAM does the following:</p>\n         <ul>\n            <li>\n               <p>Deallocates any CIDRs allocated to VPC resources (such as VPCs) in pools in private scopes.</p>\n               <note>\n                  <p>No VPC resources are deleted as a result of enabling this option. The CIDR associated with the resource will no longer be allocated from an IPAM pool, but the CIDR itself will remain unchanged.</p>\n               </note>\n            </li>\n            <li>\n               <p>Deprovisions all IPv4 CIDRs provisioned to IPAM pools in private scopes.</p>\n            </li>\n            <li>\n               <p>Deletes all IPAM pools in private scopes.</p>\n            </li>\n            <li>\n               <p>Deletes all non-default private scopes in the IPAM.</p>\n            </li>\n            <li>\n               <p>Deletes the default public and private scopes and the IPAM.</p>\n            </li>\n         </ul>"
                     }
                 }
@@ -17229,12 +18279,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamScopeId": {
                     "target": "com.amazonaws.ec2#IpamScopeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the scope to delete.</p>",
                         "smithy.api#required": {}
                     }
@@ -17285,6 +18338,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -17309,6 +18364,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -17357,6 +18414,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -17375,6 +18434,7 @@
                 "Versions": {
                     "target": "com.amazonaws.ec2#VersionStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The version numbers of one or more launch template versions to delete.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "LaunchTemplateVersion"
@@ -17405,6 +18465,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VersionNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The version number of the launch template.</p>",
                         "smithy.api#xmlName": "versionNumber"
                     }
@@ -17454,6 +18516,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VersionNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The version number of the launch template.</p>",
                         "smithy.api#xmlName": "versionNumber"
                     }
@@ -17511,6 +18575,7 @@
                 "DestinationCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR range for the route. This must match the CIDR for the route exactly.</p>",
                         "smithy.api#required": {}
                     }
@@ -17518,6 +18583,7 @@
                 "LocalGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#LocalGatewayRoutetableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the local gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -17525,6 +18591,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -17561,6 +18629,7 @@
                 "LocalGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#LocalGatewayRoutetableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>\n      The ID of the local gateway route table.\n      </p>",
                         "smithy.api#required": {}
                     }
@@ -17568,6 +18637,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -17603,6 +18674,7 @@
                 "LocalGatewayRouteTableVirtualInterfaceGroupAssociationId": {
                     "target": "com.amazonaws.ec2#LocalGatewayRouteTableVirtualInterfaceGroupAssociationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>\n         The ID of the local gateway route table virtual interface group association.\n      </p>",
                         "smithy.api#required": {}
                     }
@@ -17610,6 +18682,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -17645,6 +18719,7 @@
                 "LocalGatewayRouteTableVpcAssociationId": {
                     "target": "com.amazonaws.ec2#LocalGatewayRouteTableVpcAssociationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the association.</p>",
                         "smithy.api#required": {}
                     }
@@ -17652,6 +18727,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -17688,12 +18765,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "PrefixListId": {
                     "target": "com.amazonaws.ec2#PrefixListResourceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the prefix list.</p>",
                         "smithy.api#required": {}
                     }
@@ -17731,12 +18811,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "NatGatewayId": {
                     "target": "com.amazonaws.ec2#NatGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the NAT gateway.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "NatGatewayId"
@@ -17788,6 +18871,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -17796,6 +18881,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Egress",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the rule is an egress rule.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "egress"
@@ -17805,6 +18892,7 @@
                     "target": "com.amazonaws.ec2#NetworkAclId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkAclId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network ACL.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkAclId"
@@ -17814,6 +18902,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RuleNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The rule number of the entry to delete.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ruleNumber"
@@ -17828,6 +18918,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -17836,6 +18928,7 @@
                     "target": "com.amazonaws.ec2#NetworkAclId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkAclId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network ACL.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkAclId"
@@ -17873,6 +18966,7 @@
                 "NetworkInsightsAccessScopeAnalysisId": {
                     "target": "com.amazonaws.ec2#NetworkInsightsAccessScopeAnalysisId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Network Access Scope analysis.</p>",
                         "smithy.api#required": {}
                     }
@@ -17880,6 +18974,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -17904,12 +19000,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "NetworkInsightsAccessScopeId": {
                     "target": "com.amazonaws.ec2#NetworkInsightsAccessScopeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Network Access Scope.</p>",
                         "smithy.api#required": {}
                     }
@@ -17947,12 +19046,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "NetworkInsightsAnalysisId": {
                     "target": "com.amazonaws.ec2#NetworkInsightsAnalysisId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network insights analysis.</p>",
                         "smithy.api#required": {}
                     }
@@ -17990,12 +19092,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "NetworkInsightsPathId": {
                     "target": "com.amazonaws.ec2#NetworkInsightsPathId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the path.</p>",
                         "smithy.api#required": {}
                     }
@@ -18045,6 +19150,7 @@
                 "NetworkInterfacePermissionId": {
                     "target": "com.amazonaws.ec2#NetworkInterfacePermissionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network interface permission.</p>",
                         "smithy.api#required": {}
                     }
@@ -18052,12 +19158,16 @@
                 "Force": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specify <code>true</code> to remove the permission even if the network interface is\n\t\t\tattached to an instance.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n\t\t\tOtherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -18073,6 +19183,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds, otherwise returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -18089,6 +19201,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n            and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n            Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -18097,6 +19211,7 @@
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkInterfaceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network interface.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkInterfaceId"
@@ -18126,6 +19241,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -18134,6 +19251,7 @@
                     "target": "com.amazonaws.ec2#PlacementGroupName",
                     "traits": {
                         "aws.protocols#ec2QueryName": "GroupName",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The name of the placement group.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "groupName"
@@ -18159,12 +19277,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "PoolId": {
                     "target": "com.amazonaws.ec2#Ipv4PoolEc2Id",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the public IPv4 pool you want to delete.</p>",
                         "smithy.api#required": {}
                     }
@@ -18178,6 +19299,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ReturnValue",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Information about the result of deleting the public IPv4 pool.</p>",
                         "smithy.api#xmlName": "returnValue"
                     }
@@ -18221,22 +19344,26 @@
             }
         },
         "com.amazonaws.ec2#DeleteQueuedReservedInstancesErrorCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "reserved-instances-id-invalid",
-                        "name": "RESERVED_INSTANCES_ID_INVALID"
-                    },
-                    {
-                        "value": "reserved-instances-not-in-queued-state",
-                        "name": "RESERVED_INSTANCES_NOT_IN_QUEUED_STATE"
-                    },
-                    {
-                        "value": "unexpected-error",
-                        "name": "UNEXPECTED_ERROR"
+            "type": "enum",
+            "members": {
+                "RESERVED_INSTANCES_ID_INVALID": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "reserved-instances-id-invalid"
                     }
-                ]
+                },
+                "RESERVED_INSTANCES_NOT_IN_QUEUED_STATE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "reserved-instances-not-in-queued-state"
+                    }
+                },
+                "UNEXPECTED_ERROR": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unexpected-error"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DeleteQueuedReservedInstancesIdList": {
@@ -18260,12 +19387,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n      and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n      Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ReservedInstancesIds": {
                     "target": "com.amazonaws.ec2#DeleteQueuedReservedInstancesIdList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the Reserved Instances.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ReservedInstancesId"
@@ -18335,6 +19465,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -18343,6 +19475,7 @@
                     "target": "com.amazonaws.ec2#RouteTableId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RouteTableId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the route table.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "routeTableId"
@@ -18369,6 +19502,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -18377,6 +19512,7 @@
                     "target": "com.amazonaws.ec2#RouteTableId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RouteTableId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the route table.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "routeTableId"
@@ -18415,6 +19551,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -18439,6 +19577,7 @@
                 "SnapshotId": {
                     "target": "com.amazonaws.ec2#SnapshotId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the EBS snapshot.</p>",
                         "smithy.api#required": {}
                     }
@@ -18447,6 +19586,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -18472,6 +19613,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -18511,6 +19654,7 @@
                 "SubnetCidrReservationId": {
                     "target": "com.amazonaws.ec2#SubnetCidrReservationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the subnet CIDR reservation.</p>",
                         "smithy.api#required": {}
                     }
@@ -18518,6 +19662,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -18542,6 +19688,7 @@
                 "SubnetId": {
                     "target": "com.amazonaws.ec2#SubnetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the subnet.</p>",
                         "smithy.api#required": {}
                     }
@@ -18550,6 +19697,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -18575,6 +19724,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -18583,6 +19734,7 @@
                     "target": "com.amazonaws.ec2#ResourceIdList",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ResourceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the resources, separated by spaces.</p>\n   \t     <p>Constraints: Up to 1000 resource IDs. We recommend breaking up this request into smaller batches.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "resourceId"
@@ -18616,6 +19768,7 @@
                 "TrafficMirrorFilterId": {
                     "target": "com.amazonaws.ec2#TrafficMirrorFilterId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Traffic Mirror filter.</p>",
                         "smithy.api#required": {}
                     }
@@ -18623,6 +19776,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -18659,6 +19814,7 @@
                 "TrafficMirrorFilterRuleId": {
                     "target": "com.amazonaws.ec2#TrafficMirrorFilterRuleId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Traffic Mirror rule.</p>",
                         "smithy.api#required": {}
                     }
@@ -18666,6 +19822,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -18702,6 +19860,7 @@
                 "TrafficMirrorSessionId": {
                     "target": "com.amazonaws.ec2#TrafficMirrorSessionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Traffic Mirror session.</p>",
                         "smithy.api#required": {}
                     }
@@ -18709,6 +19868,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -18745,6 +19906,7 @@
                 "TrafficMirrorTargetId": {
                     "target": "com.amazonaws.ec2#TrafficMirrorTargetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Traffic Mirror target.</p>",
                         "smithy.api#required": {}
                     }
@@ -18752,6 +19914,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -18812,6 +19976,7 @@
                 "TransitGatewayConnectPeerId": {
                     "target": "com.amazonaws.ec2#TransitGatewayConnectPeerId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Connect peer.</p>",
                         "smithy.api#required": {}
                     }
@@ -18819,6 +19984,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -18843,6 +20010,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Connect attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -18850,6 +20018,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -18886,6 +20056,7 @@
                 "TransitGatewayMulticastDomainId": {
                     "target": "com.amazonaws.ec2#TransitGatewayMulticastDomainId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway multicast domain.</p>",
                         "smithy.api#required": {}
                     }
@@ -18893,6 +20064,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -18929,6 +20102,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway peering attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -18936,6 +20110,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -18972,6 +20148,7 @@
                 "TransitGatewayPolicyTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayPolicyTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The transit gateway policy table to delete.</p>",
                         "smithy.api#required": {}
                     }
@@ -18979,6 +20156,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -19015,6 +20194,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -19022,6 +20202,7 @@
                 "PrefixListId": {
                     "target": "com.amazonaws.ec2#PrefixListResourceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the prefix list.</p>",
                         "smithy.api#required": {}
                     }
@@ -19029,6 +20210,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -19053,6 +20236,7 @@
                 "TransitGatewayId": {
                     "target": "com.amazonaws.ec2#TransitGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -19060,6 +20244,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -19096,6 +20282,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -19103,6 +20290,7 @@
                 "DestinationCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR range for the route. This must match the CIDR for the route exactly.</p>",
                         "smithy.api#required": {}
                     }
@@ -19110,6 +20298,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -19158,6 +20348,7 @@
                 "TransitGatewayRouteTableAnnouncementId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableAnnouncementId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The transit gateway route table ID that's being deleted. </p>",
                         "smithy.api#required": {}
                     }
@@ -19165,6 +20356,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -19189,6 +20382,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -19196,6 +20390,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -19232,6 +20428,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -19239,6 +20436,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -19275,6 +20474,7 @@
                 "VolumeId": {
                     "target": "com.amazonaws.ec2#VolumeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the volume.</p>",
                         "smithy.api#required": {}
                     }
@@ -19283,6 +20483,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -19319,12 +20521,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ConnectionNotificationIds": {
                     "target": "com.amazonaws.ec2#ConnectionNotificationIdsList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>One or more notification IDs.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ConnectionNotificationId"
@@ -19363,12 +20568,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ServiceIds": {
                     "target": "com.amazonaws.ec2#VpcEndpointServiceIdList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of one or more services.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ServiceId"
@@ -19407,12 +20615,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "VpcEndpointIds": {
                     "target": "com.amazonaws.ec2#VpcEndpointIdList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>One or more VPC endpoint IDs.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "VpcEndpointId"
@@ -19458,6 +20669,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -19466,6 +20679,7 @@
                     "target": "com.amazonaws.ec2#VpcPeeringConnectionId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcPeeringConnectionId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC peering connection.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcPeeringConnectionId"
@@ -19480,6 +20694,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -19492,6 +20708,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {}
                     }
@@ -19500,6 +20717,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -19524,6 +20743,7 @@
                 "VpnConnectionId": {
                     "target": "com.amazonaws.ec2#VpnConnectionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPN connection.</p>",
                         "smithy.api#required": {}
                     }
@@ -19532,6 +20752,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -19559,6 +20781,7 @@
                 "DestinationCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR block associated with the local subnet of the customer network.</p>",
                         "smithy.api#required": {}
                     }
@@ -19566,6 +20789,7 @@
                 "VpnConnectionId": {
                     "target": "com.amazonaws.ec2#VpnConnectionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPN connection.</p>",
                         "smithy.api#required": {}
                     }
@@ -19593,6 +20817,7 @@
                 "VpnGatewayId": {
                     "target": "com.amazonaws.ec2#VpnGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the virtual private gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -19601,6 +20826,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -19628,6 +20855,7 @@
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The address range, in CIDR notation. The prefix must be the same prefix \n         that you specified when you provisioned the address range.</p>",
                         "smithy.api#required": {}
                     }
@@ -19635,6 +20863,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -19671,12 +20901,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamPoolId": {
                     "target": "com.amazonaws.ec2#IpamPoolId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the pool that has the CIDR you want to deprovision.</p>",
                         "smithy.api#required": {}
                     }
@@ -19720,12 +20953,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "PoolId": {
                     "target": "com.amazonaws.ec2#Ipv4PoolEc2Id",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the pool that you want to deprovision the CIDR from.</p>",
                         "smithy.api#required": {}
                     }
@@ -19733,6 +20969,7 @@
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR you want to deprovision from the pool.</p>",
                         "smithy.api#required": {}
                     }
@@ -19787,6 +21024,7 @@
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AMI.</p>",
                         "smithy.api#required": {}
                     }
@@ -19795,6 +21033,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -19822,6 +21062,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -19852,6 +21094,8 @@
                 "IncludeAllTagsOfInstance": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to deregister all tag keys in the current Region. Specify <code>false</code> \n   \t\tto deregister all tag keys.</p>"
                     }
                 },
@@ -19903,6 +21147,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -19957,6 +21203,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -20002,6 +21250,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n           and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n           Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -20076,12 +21326,16 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#AddressMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call. To retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -20136,6 +21390,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -20173,6 +21429,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -20185,6 +21443,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "UseLongIdsAggregated",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether all resource types in the Region are configured to use longer IDs.\n            This value is only <code>true</code> if all users are configured to use longer IDs for\n            all resources types in the Region.</p>",
                         "smithy.api#xmlName": "useLongIdsAggregated"
                     }
@@ -20238,6 +21498,8 @@
                 "AllAvailabilityZones": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Include all Availability Zones, Local Zones, and Wavelength Zones regardless of your\n      opt-in status.</p>\n         <p>If you do not use this parameter, the results include only the zones for the Regions where you have chosen the option to opt in.</p>"
                     }
                 },
@@ -20245,6 +21507,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -20324,6 +21588,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -20364,6 +21630,7 @@
         "com.amazonaws.ec2#DescribeByoipCidrsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 100
@@ -20376,12 +21643,16 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeByoipCidrsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>",
                         "smithy.api#required": {}
                     }
@@ -20436,6 +21707,7 @@
         "com.amazonaws.ec2#DescribeCapacityReservationFleetsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 100
@@ -20461,6 +21733,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeCapacityReservationFleetsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the returned <code>nextToken</code> value. This value can be between 5 and 500. If <code>maxResults</code> is given a larger value than 500, you receive an error.</p>"
                     }
                 },
@@ -20474,6 +21748,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -20521,6 +21797,7 @@
         "com.amazonaws.ec2#DescribeCapacityReservationsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 1000
@@ -20546,6 +21823,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeCapacityReservationsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the returned <code>nextToken</code> value. This value can be between 5 and 500. If <code>maxResults</code> is given a larger value than 500, you receive an error.</p>"
                     }
                 },
@@ -20559,6 +21838,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -20623,6 +21904,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#CarrierGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -20635,6 +21918,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -20682,6 +21967,7 @@
         "com.amazonaws.ec2#DescribeClassicLinkInstancesMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -20702,6 +21988,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -20717,6 +22005,8 @@
                     "target": "com.amazonaws.ec2#DescribeClassicLinkInstancesMaxResults",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>\n\t\t       <p>Constraint: If the value is greater than 1000, we return only 1000 items.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -20773,6 +22063,7 @@
         "com.amazonaws.ec2#DescribeClientVpnAuthorizationRulesMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -20785,6 +22076,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint.</p>",
                         "smithy.api#required": {}
                     }
@@ -20792,6 +22084,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -20811,6 +22105,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeClientVpnAuthorizationRulesMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the nextToken value.</p>"
                     }
                 }
@@ -20858,6 +22154,7 @@
         "com.amazonaws.ec2#DescribeClientVpnConnectionsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -20870,6 +22167,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint.</p>",
                         "smithy.api#required": {}
                     }
@@ -20890,12 +22188,16 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeClientVpnConnectionsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the nextToken value.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -20925,6 +22227,7 @@
         "com.amazonaws.ec2#DescribeClientVpnEndpointMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -20962,6 +22265,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeClientVpnEndpointMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the nextToken value.</p>"
                     }
                 },
@@ -20981,6 +22286,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -21028,6 +22335,7 @@
         "com.amazonaws.ec2#DescribeClientVpnRoutesMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -21040,6 +22348,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint.</p>",
                         "smithy.api#required": {}
                     }
@@ -21054,6 +22363,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeClientVpnRoutesMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the nextToken value.</p>"
                     }
                 },
@@ -21066,6 +22377,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -21113,6 +22426,7 @@
         "com.amazonaws.ec2#DescribeClientVpnTargetNetworksMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -21125,6 +22439,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint.</p>",
                         "smithy.api#required": {}
                     }
@@ -21138,6 +22453,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeClientVpnTargetNetworksMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the nextToken value.</p>"
                     }
                 },
@@ -21157,6 +22474,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -21221,6 +22540,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#CoipPoolMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -21233,6 +22554,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -21362,6 +22685,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -21451,6 +22776,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -21497,6 +22824,7 @@
         "com.amazonaws.ec2#DescribeDhcpOptionsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -21524,6 +22852,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -21537,6 +22867,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeDhcpOptionsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 }
@@ -21584,6 +22916,7 @@
         "com.amazonaws.ec2#DescribeEgressOnlyInternetGatewaysMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 255
@@ -21596,6 +22929,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -21609,6 +22944,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeEgressOnlyInternetGatewaysMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -21663,6 +23000,7 @@
         "com.amazonaws.ec2#DescribeElasticGpusMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 10,
                     "max": 1000
@@ -21682,6 +23020,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -21695,6 +23035,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeElasticGpusMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n            results, make another call with the returned <code>NextToken</code> value. This value\n            can be between 5 and 1000.</p>"
                     }
                 },
@@ -21721,6 +23063,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of items to return. If the total number of items available is more\n            than the value specified in max-items then a Next-Token will be provided in the output\n            that you can use to resume pagination.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -21756,6 +23100,7 @@
         "com.amazonaws.ec2#DescribeExportImageTasksMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 500
@@ -21768,6 +23113,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -21788,6 +23135,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeExportImageTasksMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call.</p>"
                     }
                 },
@@ -21947,6 +23296,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -21955,7 +23306,6 @@
         "com.amazonaws.ec2#DescribeFastLaunchImagesRequestMaxResults": {
             "type": "integer",
             "traits": {
-                "smithy.api#box": {},
                 "smithy.api#range": {
                     "min": 0,
                     "max": 200
@@ -22022,6 +23372,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxParallelLaunches",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of parallel instances that are launched for creating resources.</p>",
                         "smithy.api#xmlName": "maxParallelLaunches"
                     }
@@ -22198,7 +23550,6 @@
         "com.amazonaws.ec2#DescribeFastSnapshotRestoresMaxResults": {
             "type": "integer",
             "traits": {
-                "smithy.api#box": {},
                 "smithy.api#range": {
                     "min": 0,
                     "max": 200
@@ -22230,6 +23581,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -22314,6 +23667,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -22326,6 +23681,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. Specify a value between 1 and\n         1000. The default value is 1000. To retrieve the remaining results, make another call with\n         the returned <code>NextToken</code> value.</p>"
                     }
                 },
@@ -22338,6 +23695,7 @@
                 "FleetId": {
                     "target": "com.amazonaws.ec2#FleetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the EC2 Fleet.</p>",
                         "smithy.api#required": {}
                     }
@@ -22345,6 +23703,7 @@
                 "StartTime": {
                     "target": "com.amazonaws.ec2#DateTime",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The start date and time for the events, in UTC format (for example,\n            <i>YYYY</i>-<i>MM</i>-<i>DD</i>T<i>HH</i>:<i>MM</i>:<i>SS</i>Z).</p>",
                         "smithy.api#required": {}
                     }
@@ -22414,12 +23773,16 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. Specify a value between 1 and\n         1000. The default value is 1000. To retrieve the remaining results, make another call with\n         the returned <code>NextToken</code> value.</p>"
                     }
                 },
@@ -22432,6 +23795,7 @@
                 "FleetId": {
                     "target": "com.amazonaws.ec2#FleetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the EC2 Fleet.</p>",
                         "smithy.api#required": {}
                     }
@@ -22564,12 +23928,16 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. Specify a value between 1 and\n         1000. The default value is 1000. To retrieve the remaining results, make another call with\n         the returned <code>NextToken</code> value.</p>"
                     }
                 },
@@ -22640,6 +24008,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -22659,6 +24029,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -22709,12 +24081,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "FpgaImageId": {
                     "target": "com.amazonaws.ec2#FpgaImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AFI.</p>",
                         "smithy.api#required": {}
                     }
@@ -22722,6 +24097,7 @@
                 "Attribute": {
                     "target": "com.amazonaws.ec2#FpgaImageAttributeName",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The AFI attribute.</p>",
                         "smithy.api#required": {}
                     }
@@ -22762,6 +24138,7 @@
         "com.amazonaws.ec2#DescribeFpgaImagesMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -22774,6 +24151,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -22807,6 +24186,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeFpgaImagesMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call.</p>"
                     }
                 }
@@ -22863,18 +24244,24 @@
                 "MaxDuration": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>This is the maximum duration of the reservation to purchase, specified in seconds.\n            Reservations are available in one-year and three-year terms. The number of seconds\n            specified must be the number of seconds in a year (365x24x60x60) times one of the\n            supported durations (1 or 3). For example, specify 94608000 for three years.</p>"
                     }
                 },
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeHostReservationsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the returned <code>nextToken</code> value. This value can be between 5 and 500. If <code>maxResults</code> is given a larger value than 500, you receive an error.</p>"
                     }
                 },
                 "MinDuration": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>This is the minimum duration of the reservation you'd like to purchase, specified\n            in seconds. Reservations are available in one-year and three-year terms. The number of\n            seconds specified must be the number of seconds in a year (365x24x60x60) times one of\n            the supported durations (1 or 3). For example, specify 31536000 for one year.</p>"
                     }
                 },
@@ -22934,6 +24321,7 @@
         "com.amazonaws.ec2#DescribeHostReservationsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 500
@@ -22958,6 +24346,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the returned <code>nextToken</code> value. This value can be between 5 and 500. If <code>maxResults</code> is given a larger value than 500, you receive an error.</p>"
                     }
                 },
@@ -23031,6 +24421,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the returned <code>nextToken</code> value. This value can be between 5 and 500. If <code>maxResults</code> is given a larger value than 500, you receive an error.</p> \n         <p>You cannot specify this parameter and the host IDs parameter in the same request.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -23087,6 +24479,7 @@
         "com.amazonaws.ec2#DescribeIamInstanceProfileAssociationsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -23113,6 +24506,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeIamInstanceProfileAssociationsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n            results, make another call with the returned <code>NextToken</code> value.</p>"
                     }
                 },
@@ -23200,6 +24595,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PrincipalArn",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ARN of the principal, which can be an IAM role, IAM user, or the root user.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "principalArn"
@@ -23246,6 +24642,7 @@
                 "Attribute": {
                     "target": "com.amazonaws.ec2#ImageAttributeName",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The AMI attribute.</p>\n   \t     <p>\n            <b>Note</b>: The <code>blockDeviceMapping</code> attribute is deprecated. \n   \t    Using this attribute returns the <code>Client.AuthFailure</code> error. To get information about \n   \t    the block device mappings for an AMI, use the <a>DescribeImages</a> action.</p>",
                         "smithy.api#required": {}
                     }
@@ -23253,6 +24650,7 @@
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AMI.</p>",
                         "smithy.api#required": {}
                     }
@@ -23261,6 +24659,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -23367,6 +24767,8 @@
                 "IncludeDeprecated": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If <code>true</code>, all deprecated AMIs are included in the response. If\n        <code>false</code>, no deprecated AMIs are included in the response. If no value is\n      specified, the default value is <code>false</code>.</p>\n         <note>\n            <p>If you are the AMI owner, all deprecated AMIs appear in the response regardless of the value (<code>true</code> or <code>false</code>) that you set for this parameter.</p>\n         </note>"
                     }
                 },
@@ -23374,6 +24776,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -23417,6 +24821,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -23437,6 +24843,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call.</p>"
                     }
                 },
@@ -23493,6 +24901,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -23513,6 +24923,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining results, make another call\n   with the returned <code>NextToken</code> value.</p>"
                     }
                 },
@@ -23564,6 +24976,7 @@
                     "target": "com.amazonaws.ec2#InstanceAttributeName",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Attribute",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The instance attribute.</p>\n        <p>Note: The <code>enaSupport</code> attribute is not supported at this time.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "attribute"
@@ -23573,6 +24986,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -23581,6 +24996,7 @@
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "instanceId"
@@ -23609,6 +25025,7 @@
         "com.amazonaws.ec2#DescribeInstanceCreditSpecificationsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -23621,6 +25038,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -23641,6 +25060,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeInstanceCreditSpecificationsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n            results, make another call with the returned <code>NextToken</code> value. This value\n            can be between 5 and 1000. You cannot specify this parameter and the instance IDs\n            parameter in the same call.</p>"
                     }
                 },
@@ -23691,6 +25112,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -23733,6 +25156,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -23753,6 +25178,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#ResultRange",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n         results, make another call with the returned <code>NextToken</code> value. This value can\n         be between 20 and 500. You cannot specify this parameter and the event window IDs parameter\n         in the same call.</p>"
                     }
                 },
@@ -23867,6 +25294,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n            results, make another call with the returned <code>NextToken</code> value. This value\n            can be between 5 and 1000. You cannot specify this parameter and the instance IDs\n            parameter in the same call.</p>"
                     }
                 },
@@ -23880,6 +25309,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -23888,6 +25319,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "IncludeAllInstances",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>When <code>true</code>, includes the health status for all instances. When\n                <code>false</code>, includes the health status for running instances only.</p>\n        <p>Default: <code>false</code>\n        </p>",
                         "smithy.api#xmlName": "includeAllInstances"
                     }
@@ -23939,6 +25372,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request,\n         and provides an error response. If you have the required permissions, the error response is\n         <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -24014,6 +25449,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request,\n         and provides an error response. If you have the required permissions, the error response is\n         <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -24252,6 +25689,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -24260,6 +25699,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n            results, make another call with the returned <code>NextToken</code> value. This value\n            can be between 5 and 1000. You cannot specify this parameter and the instance IDs\n            parameter in the same call.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -24342,6 +25783,7 @@
         "com.amazonaws.ec2#DescribeInternetGatewaysMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -24362,6 +25804,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -24383,6 +25827,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeInternetGatewaysMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 }
@@ -24433,6 +25879,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -24446,6 +25894,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#IpamMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in the request.</p>"
                     }
                 },
@@ -24509,6 +25959,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -24522,6 +25974,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#IpamMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in the request.</p>"
                     }
                 },
@@ -24585,6 +26039,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -24598,6 +26054,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#IpamMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in the request.</p>"
                     }
                 },
@@ -24674,12 +26132,16 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Ipv6PoolMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -24779,6 +26241,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -24786,6 +26250,8 @@
                 "IncludePublicKey": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If <code>true</code>, the public key material is included in the response.</p>\n        <p>Default: <code>false</code>\n         </p>"
                     }
                 }
@@ -24828,6 +26294,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -24871,6 +26339,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n            results, make another call with the returned <code>NextToken</code> value. This value\n            can be between 1 and 200.</p>"
                     }
                 },
@@ -24925,6 +26395,7 @@
         "com.amazonaws.ec2#DescribeLaunchTemplatesMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 200
@@ -24937,6 +26408,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -24970,6 +26443,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeLaunchTemplatesMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n            results, make another call with the returned <code>NextToken</code> value. This value\n            can be between 1 and 200.</p>"
                     }
                 }
@@ -25034,6 +26509,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#LocalGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -25046,6 +26523,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -25110,6 +26589,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#LocalGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -25122,6 +26603,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -25186,6 +26669,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#LocalGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -25198,6 +26683,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -25262,6 +26749,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#LocalGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -25274,6 +26763,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -25338,6 +26829,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#LocalGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -25350,6 +26843,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -25414,6 +26909,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#LocalGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -25426,6 +26923,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -25476,6 +26975,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -25489,6 +26990,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#PrefixListMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -25549,6 +27052,7 @@
         "com.amazonaws.ec2#DescribeMovingAddressesMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -25570,6 +27074,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -25578,6 +27084,8 @@
                     "target": "com.amazonaws.ec2#DescribeMovingAddressesMaxResults",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining\n      results of the initial request can be seen by sending another request with the returned\n      <code>NextToken</code> value. This value can be between 5 and 1000; if\n      <code>MaxResults</code> is given a value outside of this range, an error is returned.</p>\n         <p>Default: If no value is provided, the default is 1000.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -25719,6 +27227,7 @@
         "com.amazonaws.ec2#DescribeNatGatewaysMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -25731,6 +27240,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -25743,6 +27254,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeNatGatewaysMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -25803,6 +27316,7 @@
         "com.amazonaws.ec2#DescribeNetworkAclsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -25823,6 +27337,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -25843,6 +27359,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeNetworkAclsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 }
@@ -25925,12 +27443,16 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#NetworkInsightsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n   To retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -26001,12 +27523,16 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#NetworkInsightsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n   To retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -26095,12 +27621,16 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#NetworkInsightsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n   To retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -26171,12 +27701,16 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#NetworkInsightsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n   To retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -26236,6 +27770,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n       and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n       Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -26244,6 +27780,7 @@
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkInterfaceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network interface.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkInterfaceId"
@@ -26323,6 +27860,7 @@
         "com.amazonaws.ec2#DescribeNetworkInterfacePermissionsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 255
@@ -26355,6 +27893,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeNetworkInterfacePermissionsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining results,\n\t\t\tmake another call with the returned <code>NextToken</code> value. If this parameter is not specified, up to 50 results are returned by default.</p>"
                     }
                 }
@@ -26434,6 +27974,7 @@
         "com.amazonaws.ec2#DescribeNetworkInterfacesMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -26455,6 +27996,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n       and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n       Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -26475,6 +28018,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeNetworkInterfacesMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of items to return for this request. The request returns a token that you\n            can specify in a subsequent call to get the next set of results. You cannot specify this\n            parameter and the network interface IDs parameter in the same request.</p>"
                     }
                 }
@@ -26533,6 +28078,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -26591,6 +28138,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -26604,6 +28153,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -26664,6 +28215,7 @@
         "com.amazonaws.ec2#DescribePrincipalIdFormatMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 1000
@@ -26676,6 +28228,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -26689,6 +28243,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribePrincipalIdFormatMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n            results, make another call with the returned NextToken value. </p>"
                     }
                 },
@@ -26758,6 +28314,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#PoolMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -26824,6 +28382,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -26831,6 +28391,8 @@
                 "AllRegions": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to display all Regions, including Regions that are disabled for your account.</p>"
                     }
                 }
@@ -26870,6 +28432,7 @@
         "com.amazonaws.ec2#DescribeReplaceRootVolumeTasksMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 50
@@ -26896,6 +28459,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeReplaceRootVolumeTasksMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -26908,6 +28473,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -27113,6 +28680,8 @@
                 "IncludeMarketplace": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Include Reserved Instance Marketplace offerings in the response.</p>"
                     }
                 },
@@ -27125,18 +28694,24 @@
                 "MaxDuration": {
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum duration (in seconds) to filter when searching for offerings.</p>\n\t\t       <p>Default: 94608000 (3 years)</p>"
                     }
                 },
                 "MaxInstanceCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of instances to filter when searching for offerings.</p>\n\t\t       <p>Default: 20</p>"
                     }
                 },
                 "MinDuration": {
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum duration (in seconds) to filter when searching for offerings.</p>\n\t\t       <p>Default: 2592000 (1 month)</p>"
                     }
                 },
@@ -27163,6 +28738,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n       and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n       Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -27179,6 +28756,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining\n\t\t\tresults of the initial request can be seen by sending another request with the returned\n\t\t\t\t<code>NextToken</code> value. The maximum is 100.</p>\n\t\t       <p>Default: 100</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -27255,6 +28834,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n       and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n       Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -27309,6 +28890,7 @@
         "com.amazonaws.ec2#DescribeRouteTablesMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 100
@@ -27329,6 +28911,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -27349,6 +28933,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeRouteTablesMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 }
@@ -27399,6 +28985,7 @@
         "com.amazonaws.ec2#DescribeScheduledInstanceAvailabilityMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 300
@@ -27411,6 +28998,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -27424,6 +29013,7 @@
                 "FirstSlotStartTimeRange": {
                     "target": "com.amazonaws.ec2#SlotDateTimeRangeRequest",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The time period for the first schedule to start.</p>",
                         "smithy.api#required": {}
                     }
@@ -27431,18 +29021,24 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeScheduledInstanceAvailabilityMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. \n         This value can be between 5 and 300. The default value is 300.\n         To retrieve the remaining results, make another call with the returned\n         <code>NextToken</code> value.</p>"
                     }
                 },
                 "MaxSlotDurationInHours": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum available duration, in hours. This value must be greater than <code>MinSlotDurationInHours</code>\n         and less than 1,720.</p>"
                     }
                 },
                 "MinSlotDurationInHours": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum available duration, in hours. The minimum required duration is 1,200 hours per year. For example, the minimum daily schedule is 4 hours, the minimum weekly schedule is 24 hours, and the minimum monthly schedule is 100 hours.</p>"
                     }
                 },
@@ -27455,6 +29051,7 @@
                 "Recurrence": {
                     "target": "com.amazonaws.ec2#ScheduledInstanceRecurrenceRequest",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The schedule recurrence.</p>",
                         "smithy.api#required": {}
                     }
@@ -27512,6 +29109,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -27525,6 +29124,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. \n         This value can be between 5 and 300. The default value is 100.\n         To retrieve the remaining results, make another call with the returned\n         <code>NextToken</code> value.</p>"
                     }
                 },
@@ -27594,12 +29195,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "GroupId": {
                     "target": "com.amazonaws.ec2#GroupIds",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the security groups in your account.</p>",
                         "smithy.api#required": {}
                     }
@@ -27640,6 +29244,7 @@
         "com.amazonaws.ec2#DescribeSecurityGroupRulesMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -27666,6 +29271,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -27678,6 +29285,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeSecurityGroupRulesMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n            results, make another request with the returned <code>NextToken</code> value. This value\n            can be between 5 and 1000. If this parameter is not specified, then all results are\n            returned.</p>"
                     }
                 }
@@ -27751,6 +29360,7 @@
         "com.amazonaws.ec2#DescribeSecurityGroupsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -27785,6 +29395,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -27798,6 +29410,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeSecurityGroupsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n            results, make another request with the returned <code>NextToken</code> value. This value\n            can be between 5 and 1000. If this parameter is not specified, then all results are\n            returned.</p>"
                     }
                 }
@@ -27842,6 +29456,7 @@
                 "Attribute": {
                     "target": "com.amazonaws.ec2#SnapshotAttributeName",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The snapshot attribute you would like to view.</p>",
                         "smithy.api#required": {}
                     }
@@ -27849,6 +29464,7 @@
                 "SnapshotId": {
                     "target": "com.amazonaws.ec2#SnapshotId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the EBS snapshot.</p>",
                         "smithy.api#required": {}
                     }
@@ -27857,6 +29473,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -27911,10 +29529,7 @@
             }
         },
         "com.amazonaws.ec2#DescribeSnapshotTierStatusMaxResults": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#DescribeSnapshotTierStatusRequest": {
             "type": "structure",
@@ -27929,6 +29544,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -28025,6 +29642,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of snapshot results returned by <code>DescribeSnapshots</code> in\n      paginated output. When this parameter is used, <code>DescribeSnapshots</code> only returns\n        <code>MaxResults</code> results in a single page along with a <code>NextToken</code>\n      response element. The remaining results of the initial request can be seen by sending another\n        <code>DescribeSnapshots</code> request with the returned <code>NextToken</code> value. This\n      value can be between 5 and 1,000; if <code>MaxResults</code> is given a value larger than 1,000,\n      only 1,000 results are returned. If this parameter is not used, then\n        <code>DescribeSnapshots</code> returns all results. You cannot specify this parameter and\n      the snapshot IDs parameter in the same request.</p>"
                     }
                 },
@@ -28059,6 +29678,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -28105,6 +29726,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -28145,6 +29768,7 @@
         "com.amazonaws.ec2#DescribeSpotFleetInstancesMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 1000
@@ -28158,6 +29782,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -28166,6 +29792,8 @@
                     "target": "com.amazonaws.ec2#DescribeSpotFleetInstancesMaxResults",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. Specify a value between 1\n            and 1000. The default value is 1000. To retrieve the remaining results, make another\n            call with the returned <code>NextToken</code> value.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -28182,6 +29810,7 @@
                     "target": "com.amazonaws.ec2#SpotFleetRequestId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SpotFleetRequestId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Spot Fleet request.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "spotFleetRequestId"
@@ -28239,6 +29868,7 @@
         "com.amazonaws.ec2#DescribeSpotFleetRequestHistoryMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 1000
@@ -28252,6 +29882,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -28268,6 +29900,8 @@
                     "target": "com.amazonaws.ec2#DescribeSpotFleetRequestHistoryMaxResults",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. Specify a value between 1\n            and 1000. The default value is 1000. To retrieve the remaining results, make another\n            call with the returned <code>NextToken</code> value.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -28284,6 +29918,7 @@
                     "target": "com.amazonaws.ec2#SpotFleetRequestId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SpotFleetRequestId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Spot Fleet request.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "spotFleetRequestId"
@@ -28293,6 +29928,7 @@
                     "target": "com.amazonaws.ec2#DateTime",
                     "traits": {
                         "aws.protocols#ec2QueryName": "StartTime",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The starting date and time for the events, in UTC format (for example,\n                <i>YYYY</i>-<i>MM</i>-<i>DD</i>T<i>HH</i>:<i>MM</i>:<i>SS</i>Z).</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "startTime"
@@ -28376,6 +30012,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -28384,6 +30022,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. Specify a value between 1\n            and 1000. The default value is 1000. To retrieve the remaining results, make another\n            call with the returned <code>NextToken</code> value.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -28541,6 +30181,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -28561,6 +30203,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. Specify a value between 5\n            and 1000. To retrieve the remaining results, make another call with the returned\n                <code>NextToken</code> value.</p>"
                     }
                 }
@@ -28633,6 +30277,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -28656,6 +30302,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. Specify a value between 1\n            and 1000. The default value is 1000. To retrieve the remaining results, make another\n            call with the returned <code>NextToken</code> value.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -28733,6 +30381,7 @@
         "com.amazonaws.ec2#DescribeStaleSecurityGroupsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 255
@@ -28754,12 +30403,16 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeStaleSecurityGroupsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of items to return for this request. The request returns a token that you can specify in a subsequent call to get the next set of results.</p>"
                     }
                 },
@@ -28772,6 +30425,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {}
                     }
@@ -28830,6 +30484,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -28849,6 +30505,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeStoreImageTasksRequestMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n      results, make another call with the returned <code>NextToken</code> value. This value can be\n      between 1 and 200. You cannot specify this parameter and the <code>ImageIDs</code> parameter\n      in the same call.</p>"
                     }
                 }
@@ -28857,6 +30515,7 @@
         "com.amazonaws.ec2#DescribeStoreImageTasksRequestMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 200
@@ -28922,6 +30581,7 @@
         "com.amazonaws.ec2#DescribeSubnetsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -28949,6 +30609,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -28962,6 +30624,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeSubnetsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 }
@@ -29013,6 +30677,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -29028,6 +30694,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call.\n      This value can be between 5 and 1000. \n\t\t\tTo retrieve the remaining results, make another call with the returned <code>NextToken</code> value.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -29094,6 +30762,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -29107,6 +30777,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TrafficMirroringMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29170,6 +30842,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -29183,6 +30857,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TrafficMirroringMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29246,6 +30922,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -29259,6 +30937,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TrafficMirroringMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29328,6 +31008,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29340,6 +31022,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -29403,6 +31087,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29415,6 +31101,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -29478,6 +31166,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29490,6 +31180,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -29553,6 +31245,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29565,6 +31259,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -29628,6 +31324,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29640,6 +31338,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -29703,6 +31403,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29715,6 +31417,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -29778,6 +31482,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29790,6 +31496,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -29853,6 +31561,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29865,6 +31575,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -29928,6 +31640,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -29940,6 +31654,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -30003,6 +31719,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -30015,6 +31733,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -30062,6 +31782,7 @@
         "com.amazonaws.ec2#DescribeTrunkInterfaceAssociationsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 255
@@ -30081,6 +31802,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -30100,6 +31823,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeTrunkInterfaceAssociationsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n            To retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 }
@@ -30144,6 +31869,7 @@
                 "Attribute": {
                     "target": "com.amazonaws.ec2#VolumeAttributeName",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The attribute of the volume. This parameter is required.</p>",
                         "smithy.api#required": {}
                     }
@@ -30151,6 +31877,7 @@
                 "VolumeId": {
                     "target": "com.amazonaws.ec2#VolumeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the volume.</p>",
                         "smithy.api#required": {}
                     }
@@ -30159,6 +31886,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -30225,6 +31954,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of volume results returned by <code>DescribeVolumeStatus</code> in\n      paginated output. When this parameter is used, the request only returns\n        <code>MaxResults</code> results in a single page along with a <code>NextToken</code>\n      response element. The remaining results of the initial request can be seen by sending another\n      request with the returned <code>NextToken</code> value. This value can be between 5 and 1,000;\n      if <code>MaxResults</code> is given a value larger than 1,000, only 1,000 results are returned.\n      If this parameter is not used, then <code>DescribeVolumeStatus</code> returns all results. You\n      cannot specify this parameter and the volume IDs parameter in the same request.</p>"
                     }
                 },
@@ -30245,6 +31976,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -30390,6 +32123,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -30416,6 +32151,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results (up to a limit of 500) to be returned in a paginated\n      request.</p>"
                     }
                 }
@@ -30463,6 +32200,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -30471,6 +32210,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of volume results returned by <code>DescribeVolumes</code> in paginated\n      output. When this parameter is used, <code>DescribeVolumes</code> only returns\n        <code>MaxResults</code> results in a single page along with a <code>NextToken</code>\n      response element. The remaining results of the initial request can be seen by sending another\n        <code>DescribeVolumes</code> request with the returned <code>NextToken</code> value. This\n      value can be between 5 and 500; if <code>MaxResults</code> is given a value larger than 500,\n      only 500 results are returned. If this parameter is not used, then\n        <code>DescribeVolumes</code> returns all results. You cannot specify this parameter and the\n      volume IDs parameter in the same request.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -30524,6 +32265,7 @@
                 "Attribute": {
                     "target": "com.amazonaws.ec2#VpcAttributeName",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The VPC attribute.</p>",
                         "smithy.api#required": {}
                     }
@@ -30531,6 +32273,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {}
                     }
@@ -30539,6 +32282,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -30607,6 +32352,7 @@
         "com.amazonaws.ec2#DescribeVpcClassicLinkDnsSupportMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 255
@@ -30629,6 +32375,8 @@
                     "target": "com.amazonaws.ec2#DescribeVpcClassicLinkDnsSupportMaxResults",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxResults",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>",
                         "smithy.api#xmlName": "maxResults"
                     }
@@ -30685,6 +32433,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -30735,6 +32485,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -30754,6 +32506,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. To retrieve the remaining\n            results, make another request with the returned <code>NextToken</code> value.</p>"
                     }
                 },
@@ -30810,6 +32564,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -30823,6 +32579,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining\n            results of the initial request can be seen by sending another request with the returned\n                <code>NextToken</code> value. This value can be between 5 and 1,000; if\n                <code>MaxResults</code> is given a value larger than 1,000, only 1,000 results are\n            returned.</p>"
                     }
                 },
@@ -30879,6 +32637,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -30899,6 +32659,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining\n            results of the initial request can be seen by sending another request with the returned\n                <code>NextToken</code> value. This value can be between 5 and 1,000; if\n                <code>MaxResults</code> is given a value larger than 1,000, only 1,000 results are\n            returned.</p>"
                     }
                 },
@@ -30955,12 +32717,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ServiceId": {
                     "target": "com.amazonaws.ec2#VpcEndpointServiceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the service.</p>",
                         "smithy.api#required": {}
                     }
@@ -30975,6 +32740,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining\n            results of the initial request can be seen by sending another request with the returned\n                <code>NextToken</code> value. This value can be between 5 and 1,000; if\n                <code>MaxResults</code> is given a value larger than 1,000, only 1,000 results are\n            returned.</p>"
                     }
                 },
@@ -31025,6 +32792,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -31045,6 +32814,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of items to return for this request. The request returns a token that you can specify in a subsequent call to get the next set of results.</p>\n        <p>Constraint: If the value is greater than 1,000, we return only 1,000 items.</p>"
                     }
                 },
@@ -31115,6 +32886,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -31135,6 +32908,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of items to return for this request. The request returns a token that you can specify in a subsequent call to get the next set of results.</p>\n        <p>Constraint: If the value is greater than 1,000, we return only 1,000 items.</p>"
                     }
                 },
@@ -31237,6 +33012,7 @@
         "com.amazonaws.ec2#DescribeVpcPeeringConnectionsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -31257,6 +33033,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -31277,6 +33055,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeVpcPeeringConnectionsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 }
@@ -31361,6 +33141,7 @@
         "com.amazonaws.ec2#DescribeVpcsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -31388,6 +33169,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -31401,6 +33184,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#DescribeVpcsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 }
@@ -31522,6 +33307,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -31580,6 +33367,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -31606,18 +33395,20 @@
             }
         },
         "com.amazonaws.ec2#DestinationFileFormat": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "plain-text",
-                        "name": "plain_text"
-                    },
-                    {
-                        "value": "parquet",
-                        "name": "parquet"
+            "type": "enum",
+            "members": {
+                "plain_text": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "plain-text"
                     }
-                ]
+                },
+                "parquet": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "parquet"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DestinationOptionsRequest": {
@@ -31632,12 +33423,16 @@
                 "HiveCompatiblePartitions": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to use Hive-compatible prefixes for flow logs stored in Amazon S3.\n            The default is <code>false</code>.</p>"
                     }
                 },
                 "PerHourPartition": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to partition the flow log per hour. This reduces the cost and response \n            time for queries. The default is <code>false</code>.</p>"
                     }
                 }
@@ -31661,6 +33456,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "HiveCompatiblePartitions",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to use Hive-compatible prefixes for flow logs stored in Amazon S3.</p>",
                         "smithy.api#xmlName": "hiveCompatiblePartitions"
                     }
@@ -31669,6 +33466,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PerHourPartition",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to partition the flow log per hour.</p>",
                         "smithy.api#xmlName": "perHourPartition"
                     }
@@ -31697,6 +33496,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -31705,6 +33506,7 @@
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance to unlink from the VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "instanceId"
@@ -31714,6 +33516,7 @@
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC to which the instance is linked.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcId"
@@ -31728,6 +33531,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -31753,6 +33558,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -31761,6 +33568,7 @@
                     "target": "com.amazonaws.ec2#InternetGatewayId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InternetGatewayId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the internet gateway.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "internetGatewayId"
@@ -31770,6 +33578,7 @@
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcId"
@@ -31796,6 +33605,7 @@
                     "target": "com.amazonaws.ec2#NetworkInterfaceAttachmentId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AttachmentId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the attachment.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "attachmentId"
@@ -31805,6 +33615,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n            and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n            Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -31813,6 +33625,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Force",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specifies whether to force a detachment.</p>\n        <note>\n            <ul>\n               <li>\n                    <p>Use the <code>Force</code> parameter only as a last resort to detach a network interface from a failed instance. </p>\n                </li>\n               <li>\n                    <p>If you use the <code>Force</code> parameter to detach a network interface, you might not be able to attach a different network interface to the same index on the instance without first stopping and starting the instance.</p>\n                </li>\n               <li>\n                    <p>If you force the detachment of a network interface, the <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html\">instance metadata</a>\n                        might not get updated. This means that the attributes associated\n                        with the detached network interface might still be visible. The\n                        instance metadata will get updated when you stop and start the\n                        instance.</p>\n                </li>\n            </ul>\n        </note>",
                         "smithy.api#xmlName": "force"
                     }
@@ -31846,6 +33660,8 @@
                 "Force": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Forces detachment if the previous detachment attempt did not occur cleanly (for example,\n      logging into an instance, unmounting the volume, and detaching normally). This option can lead\n      to data loss or a corrupted file system. Use this option only as a last resort to detach a\n      volume from a failed instance. The instance won't have an opportunity to flush file system\n      caches or file system metadata. If you use this option, you must perform file system check and\n      repair procedures.</p>"
                     }
                 },
@@ -31858,6 +33674,7 @@
                 "VolumeId": {
                     "target": "com.amazonaws.ec2#VolumeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the volume.</p>",
                         "smithy.api#required": {}
                     }
@@ -31866,6 +33683,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -31890,6 +33709,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {}
                     }
@@ -31897,6 +33717,7 @@
                 "VpnGatewayId": {
                     "target": "com.amazonaws.ec2#VpnGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the virtual private gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -31905,6 +33726,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -31915,18 +33738,20 @@
             }
         },
         "com.amazonaws.ec2#DeviceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ebs",
-                        "name": "ebs"
-                    },
-                    {
-                        "value": "instance-store",
-                        "name": "instance_store"
+            "type": "enum",
+            "members": {
+                "ebs": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ebs"
                     }
-                ]
+                },
+                "instance_store": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instance-store"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DhcpConfiguration": {
@@ -32080,6 +33905,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -32092,6 +33919,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EbsEncryptionByDefault",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>The updated status of encryption by default.</p>",
                         "smithy.api#xmlName": "ebsEncryptionByDefault"
                     }
@@ -32116,6 +33945,7 @@
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the image for which you’re turning off faster launching, and removing pre-provisioned snapshots.</p>",
                         "smithy.api#required": {}
                     }
@@ -32123,12 +33953,16 @@
                 "Force": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Forces the image settings to turn off faster launching for your Windows AMI. This parameter overrides \n\t\t\tany errors that are encountered while cleaning up resources in your account.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -32173,6 +34007,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxParallelLaunches",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of parallel instances to launch for creating resources.</p>",
                         "smithy.api#xmlName": "maxParallelLaunches"
                     }
@@ -32424,6 +34260,7 @@
                 "AvailabilityZones": {
                     "target": "com.amazonaws.ec2#AvailabilityZoneStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>One or more Availability Zones. For example, <code>us-east-2a</code>.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "AvailabilityZone"
@@ -32432,6 +34269,7 @@
                 "SourceSnapshotIds": {
                     "target": "com.amazonaws.ec2#SnapshotIdStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of one or more snapshots. For example, <code>snap-1234567890abcdef0</code>.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "SourceSnapshotId"
@@ -32440,6 +34278,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -32484,6 +34324,7 @@
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AMI.</p>",
                         "smithy.api#required": {}
                     }
@@ -32491,6 +34332,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -32503,6 +34346,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -32527,12 +34372,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "DelegatedAdminAccountId": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Organizations member account ID that you want to disable as IPAM account.</p>",
                         "smithy.api#required": {}
                     }
@@ -32546,6 +34394,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Success",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>The result of disabling the IPAM account.</p>",
                         "smithy.api#xmlName": "success"
                     }
@@ -32570,6 +34420,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -32582,6 +34434,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SerialConsoleAccessEnabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If <code>true</code>, access to the EC2 serial console of all instances is enabled for\n\t\t\tyour account. If <code>false</code>, access to the EC2 serial console of all instances\n\t\t\tis disabled for your account.</p>",
                         "smithy.api#xmlName": "serialConsoleAccessEnabled"
                     }
@@ -32606,6 +34460,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the propagation route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -32619,6 +34474,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -32661,6 +34518,7 @@
                 "GatewayId": {
                     "target": "com.amazonaws.ec2#VpnGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the virtual private gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -32668,6 +34526,7 @@
                 "RouteTableId": {
                     "target": "com.amazonaws.ec2#RouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -32675,6 +34534,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -32726,6 +34587,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -32739,6 +34602,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -32747,6 +34612,7 @@
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcId"
@@ -32761,6 +34627,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -32798,6 +34666,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -32822,6 +34692,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint from which to disassociate the target network.</p>",
                         "smithy.api#required": {}
                     }
@@ -32829,6 +34700,7 @@
                 "AssociationId": {
                     "target": "com.amazonaws.ec2#ClientVpnAssociationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the target network association.</p>",
                         "smithy.api#required": {}
                     }
@@ -32836,6 +34708,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -32892,6 +34766,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -32904,6 +34780,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -32928,6 +34806,7 @@
                 "AssociationId": {
                     "target": "com.amazonaws.ec2#IamInstanceProfileAssociationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IAM instance profile association.</p>",
                         "smithy.api#required": {}
                     }
@@ -32965,12 +34844,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "InstanceEventWindowId": {
                     "target": "com.amazonaws.ec2#InstanceEventWindowId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the event window.</p>",
                         "smithy.api#required": {}
                     }
@@ -32978,6 +34860,7 @@
                 "AssociationTarget": {
                     "target": "com.amazonaws.ec2#InstanceEventWindowDisassociationRequest",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>One or more targets to disassociate from the specified event window.</p>",
                         "smithy.api#required": {}
                     }
@@ -33016,6 +34899,7 @@
                     "target": "com.amazonaws.ec2#RouteTableAssociationId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AssociationId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The association ID representing the current association between the route table and subnet or gateway.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "associationId"
@@ -33025,6 +34909,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -33050,6 +34936,7 @@
                     "target": "com.amazonaws.ec2#SubnetCidrAssociationId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AssociationId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The association ID for the CIDR block.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "associationId"
@@ -33114,6 +35001,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -33150,6 +35039,7 @@
                 "TransitGatewayPolicyTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayPolicyTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the disassociated policy table.</p>",
                         "smithy.api#required": {}
                     }
@@ -33157,6 +35047,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway attachment to disassociate from the policy table.</p>",
                         "smithy.api#required": {}
                     }
@@ -33164,6 +35055,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -33200,6 +35093,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -33207,6 +35101,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -33214,6 +35109,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -33250,6 +35147,7 @@
                 "AssociationId": {
                     "target": "com.amazonaws.ec2#TrunkInterfaceAssociationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the association</p>",
                         "smithy.api#required": {}
                     }
@@ -33264,6 +35162,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -33276,6 +35176,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -33309,6 +35211,7 @@
                     "target": "com.amazonaws.ec2#VpcCidrAssociationId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AssociationId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The association ID for the CIDR block.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "associationId"
@@ -33346,10 +35249,7 @@
             }
         },
         "com.amazonaws.ec2#DiskCount": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#DiskImage": {
             "type": "structure",
@@ -33408,6 +35308,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Size",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the disk image, in GiB.</p>",
                         "smithy.api#xmlName": "size"
                     }
@@ -33424,6 +35326,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Bytes",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the disk image, in GiB.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "bytes"
@@ -33433,6 +35337,7 @@
                     "target": "com.amazonaws.ec2#DiskImageFormat",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Format",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The disk image format.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "format"
@@ -33442,6 +35347,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ImportManifestUrl",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>A presigned URL for the import manifest stored in Amazon S3 and presented here as an Amazon S3 presigned URL.\n   For information about creating a presigned URL for an Amazon S3 object, read the \"Query String Request Authentication\n   Alternative\" section of the <a href=\"https://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html\">Authenticating REST Requests</a> topic in the <i>Amazon Simple Storage Service Developer\n    Guide</i>.</p>\n         <p>For information about the import manifest referenced by this API action, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/manifest.html\">VM Import Manifest</a>.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "importManifestUrl"
@@ -33453,22 +35359,26 @@
             }
         },
         "com.amazonaws.ec2#DiskImageFormat": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "VMDK",
-                        "name": "VMDK"
-                    },
-                    {
-                        "value": "RAW",
-                        "name": "RAW"
-                    },
-                    {
-                        "value": "VHD",
-                        "name": "VHD"
+            "type": "enum",
+            "members": {
+                "VMDK": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "VMDK"
                     }
-                ]
+                },
+                "RAW": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "RAW"
+                    }
+                },
+                "VHD": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "VHD"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DiskImageList": {
@@ -33492,6 +35402,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Size",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the volume, in GiB.</p>",
                         "smithy.api#xmlName": "size"
                     }
@@ -33543,24 +35455,23 @@
             }
         },
         "com.amazonaws.ec2#DiskSize": {
-            "type": "long",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "long"
         },
         "com.amazonaws.ec2#DiskType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "hdd",
-                        "name": "hdd"
-                    },
-                    {
-                        "value": "ssd",
-                        "name": "ssd"
+            "type": "enum",
+            "members": {
+                "hdd": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "hdd"
                     }
-                ]
+                },
+                "ssd": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ssd"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DnsEntry": {
@@ -33597,22 +35508,26 @@
             }
         },
         "com.amazonaws.ec2#DnsNameState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pendingVerification",
-                        "name": "PendingVerification"
-                    },
-                    {
-                        "value": "verified",
-                        "name": "Verified"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "Failed"
+            "type": "enum",
+            "members": {
+                "PendingVerification": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pendingVerification"
                     }
-                ]
+                },
+                "Verified": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "verified"
+                    }
+                },
+                "Failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DnsOptions": {
@@ -33646,26 +35561,32 @@
             }
         },
         "com.amazonaws.ec2#DnsRecordIpType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ipv4",
-                        "name": "ipv4"
-                    },
-                    {
-                        "value": "dualstack",
-                        "name": "dualstack"
-                    },
-                    {
-                        "value": "ipv6",
-                        "name": "ipv6"
-                    },
-                    {
-                        "value": "service-defined",
-                        "name": "service_defined"
+            "type": "enum",
+            "members": {
+                "ipv4": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv4"
                     }
-                ]
+                },
+                "dualstack": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "dualstack"
+                    }
+                },
+                "ipv6": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv6"
+                    }
+                },
+                "service_defined": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "service-defined"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DnsServersOptionsModifyStructure": {
@@ -33680,6 +35601,8 @@
                 "Enabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether DNS servers should be used. Specify <code>False</code> to delete the existing DNS \n\t\t\tservers.</p>"
                     }
                 }
@@ -33689,42 +35612,48 @@
             }
         },
         "com.amazonaws.ec2#DnsSupportValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#DomainType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "vpc",
-                        "name": "vpc"
-                    },
-                    {
-                        "value": "standard",
-                        "name": "standard"
+            "type": "enum",
+            "members": {
+                "vpc": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vpc"
                     }
-                ]
+                },
+                "standard": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "standard"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#Double": {
-            "type": "double"
+            "type": "double",
+            "traits": {
+                "smithy.api#default": 0
+            }
         },
         "com.amazonaws.ec2#DoubleWithConstraints": {
             "type": "double",
             "traits": {
-                "smithy.api#box": {},
                 "smithy.api#range": {
                     "min": 0.001,
                     "max": 99.999
@@ -33732,18 +35661,20 @@
             }
         },
         "com.amazonaws.ec2#DynamicRoutingValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#EbsBlockDevice": {
@@ -33753,6 +35684,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeleteOnTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the EBS volume is deleted on instance termination. For more\n            information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/terminating-instances.html#preserving-volumes-on-termination\">Preserving Amazon EBS volumes on instance termination</a> in the\n                <i>Amazon EC2 User Guide</i>.</p>",
                         "smithy.api#xmlName": "deleteOnTermination"
                     }
@@ -33761,6 +35694,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Iops",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of I/O operations per second (IOPS). For <code>gp3</code>, <code>io1</code>, and <code>io2</code> volumes,\n            this represents the number of IOPS that are provisioned for the volume. For <code>gp2</code>\n            volumes, this represents the baseline performance of the volume and the rate at which\n            the volume accumulates I/O credits for bursting.</p>\n        <p>The following are the supported values for each volume type:</p>\n        <ul>\n            <li>\n                <p>\n                  <code>gp3</code>: 3,000-16,000 IOPS</p>\n            </li>\n            <li>\n                <p>\n                  <code>io1</code>: 100-64,000 IOPS</p>\n            </li>\n            <li>\n                <p>\n                  <code>io2</code>: 100-64,000 IOPS</p>\n            </li>\n         </ul>\n        <p>For <code>io1</code> and <code>io2</code> volumes, we guarantee 64,000 IOPS only for\n                <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html#ec2-nitro-instances\">Instances built on the\n                Nitro System</a>. Other instance families guarantee performance up to\n            32,000 IOPS.</p>\n        <p>This parameter is required for <code>io1</code> and <code>io2</code> volumes. The default for <code>gp3</code> volumes\n            is 3,000 IOPS. This parameter is not supported for <code>gp2</code>, <code>st1</code>, <code>sc1</code>, or <code>standard</code>\n            volumes.</p>",
                         "smithy.api#xmlName": "iops"
                     }
@@ -33777,6 +35712,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VolumeSize",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the volume, in GiBs. You must specify either a snapshot ID or a volume\n            size. If you specify a snapshot, the default is the snapshot size. You can specify a\n            volume size that is equal to or larger than the snapshot size.</p>\n        <p>The following are the supported volumes sizes for each volume type:</p>\n        <ul>\n            <li>\n                <p>\n                  <code>gp2</code> and <code>gp3</code>:1-16,384</p>\n            </li>\n            <li>\n                <p>\n                  <code>io1</code> and <code>io2</code>: 4-16,384</p>\n            </li>\n            <li>\n                <p>\n                  <code>st1</code> and <code>sc1</code>: 125-16,384</p>\n            </li>\n            <li>\n                <p>\n                  <code>standard</code>: 1-1,024</p>\n            </li>\n         </ul>",
                         "smithy.api#xmlName": "volumeSize"
                     }
@@ -33800,6 +35737,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Throughput",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The throughput that the volume supports, in MiB/s.</p>\n        <p>This parameter is valid only for <code>gp3</code> volumes.</p>\n        <p>Valid Range: Minimum value of 125. Maximum value of 1000.</p>",
                         "smithy.api#xmlName": "throughput"
                     }
@@ -33816,6 +35755,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the encryption state of an EBS volume is changed while being\n            restored from a backing snapshot. The effect of setting the encryption state to <code>true</code> depends on \nthe volume origin (new or from a snapshot), starting encryption state, ownership, and whether encryption by default is enabled. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSEncryption.html#encryption-parameters\">Amazon EBS encryption</a> in the <i>Amazon EC2 User Guide</i>.</p>\n        <p>In no case can you remove encryption from an encrypted volume.</p>\n        <p>Encrypted volumes can only be attached to instances that support Amazon EBS encryption. For\n            more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSEncryption.html#EBSEncryption_supported_instances\">Supported instance types</a>.</p>\n        <p>This parameter is not returned by <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeImageAttribute.html\">DescribeImageAttribute</a>.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -33826,18 +35767,20 @@
             }
         },
         "com.amazonaws.ec2#EbsEncryptionSupport": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "unsupported",
-                        "name": "unsupported"
-                    },
-                    {
-                        "value": "supported",
-                        "name": "supported"
+            "type": "enum",
+            "members": {
+                "unsupported": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unsupported"
                     }
-                ]
+                },
+                "supported": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "supported"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#EbsInfo": {
@@ -33895,6 +35838,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeleteOnTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the volume is deleted on instance termination.</p>",
                         "smithy.api#xmlName": "deleteOnTermination"
                     }
@@ -33927,6 +35872,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeleteOnTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the volume is deleted on instance termination.</p>",
                         "smithy.api#xmlName": "deleteOnTermination"
                     }
@@ -33945,22 +35892,26 @@
             }
         },
         "com.amazonaws.ec2#EbsNvmeSupport": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "unsupported",
-                        "name": "UNSUPPORTED"
-                    },
-                    {
-                        "value": "supported",
-                        "name": "SUPPORTED"
-                    },
-                    {
-                        "value": "required",
-                        "name": "REQUIRED"
+            "type": "enum",
+            "members": {
+                "UNSUPPORTED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unsupported"
                     }
-                ]
+                },
+                "SUPPORTED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "supported"
+                    }
+                },
+                "REQUIRED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "required"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#EbsOptimizedInfo": {
@@ -34020,22 +35971,26 @@
             }
         },
         "com.amazonaws.ec2#EbsOptimizedSupport": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "unsupported",
-                        "name": "unsupported"
-                    },
-                    {
-                        "value": "supported",
-                        "name": "supported"
-                    },
-                    {
-                        "value": "default",
-                        "name": "default"
+            "type": "enum",
+            "members": {
+                "unsupported": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unsupported"
                     }
-                ]
+                },
+                "supported": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "supported"
+                    }
+                },
+                "default": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "default"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#EfaInfo": {
@@ -34055,10 +36010,7 @@
             }
         },
         "com.amazonaws.ec2#EfaSupportedFlag": {
-            "type": "boolean",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "boolean"
         },
         "com.amazonaws.ec2#EgressOnlyInternetGateway": {
             "type": "structure",
@@ -34205,6 +36157,7 @@
                 "Type": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The type of Elastic Graphics accelerator. For more information about the values to specify for\n            <code>Type</code>, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/WindowsGuide/elastic-graphics.html#elastic-graphics-basics\">Elastic Graphics Basics</a>, specifically the Elastic Graphics accelerator column, in the \n            <i>Amazon Elastic Compute Cloud User Guide for Windows Instances</i>.</p>",
                         "smithy.api#required": {}
                     }
@@ -34258,29 +36211,31 @@
             }
         },
         "com.amazonaws.ec2#ElasticGpuState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ATTACHED",
-                        "name": "Attached"
+            "type": "enum",
+            "members": {
+                "Attached": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ATTACHED"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#ElasticGpuStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "OK",
-                        "name": "Ok"
-                    },
-                    {
-                        "value": "IMPAIRED",
-                        "name": "Impaired"
+            "type": "enum",
+            "members": {
+                "Ok": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "OK"
                     }
-                ]
+                },
+                "Impaired": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "IMPAIRED"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ElasticGpus": {
@@ -34353,6 +36308,7 @@
                 "Type": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>\n        \tThe type of elastic inference accelerator. The possible values are <code>eia1.medium</code>, <code>eia1.large</code>, <code>eia1.xlarge</code>, <code>eia2.medium</code>, <code>eia2.large</code>, and <code>eia2.xlarge</code>.\n        </p>",
                         "smithy.api#required": {}
                     }
@@ -34360,6 +36316,8 @@
                 "Count": {
                     "target": "com.amazonaws.ec2#ElasticInferenceAcceleratorCount",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>\n            The number of elastic inference accelerators to attach to the instance. \n        </p>\n         <p>Default: 1</p>"
                     }
                 }
@@ -34420,6 +36378,7 @@
         "com.amazonaws.ec2#ElasticInferenceAcceleratorCount": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1
                 }
@@ -34438,22 +36397,26 @@
             "type": "string"
         },
         "com.amazonaws.ec2#EnaSupport": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "unsupported",
-                        "name": "unsupported"
-                    },
-                    {
-                        "value": "supported",
-                        "name": "supported"
-                    },
-                    {
-                        "value": "required",
-                        "name": "required"
+            "type": "enum",
+            "members": {
+                "unsupported": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unsupported"
                     }
-                ]
+                },
+                "supported": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "supported"
+                    }
+                },
+                "required": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "required"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#EnableEbsEncryptionByDefault": {
@@ -34474,6 +36437,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -34486,6 +36451,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EbsEncryptionByDefault",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>The updated status of encryption by default.</p>",
                         "smithy.api#xmlName": "ebsEncryptionByDefault"
                     }
@@ -34510,6 +36477,7 @@
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the image for which you’re enabling faster launching.</p>",
                         "smithy.api#required": {}
                     }
@@ -34535,12 +36503,16 @@
                 "MaxParallelLaunches": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of parallel instances to launch for creating resources. Value must be <code>6</code> or greater. </p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -34585,6 +36557,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxParallelLaunches",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of parallel instances to launch for creating resources.</p>",
                         "smithy.api#xmlName": "maxParallelLaunches"
                     }
@@ -34836,6 +36810,7 @@
                 "AvailabilityZones": {
                     "target": "com.amazonaws.ec2#AvailabilityZoneStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>One or more Availability Zones. For example, <code>us-east-2a</code>.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "AvailabilityZone"
@@ -34844,6 +36819,7 @@
                 "SourceSnapshotIds": {
                     "target": "com.amazonaws.ec2#SnapshotIdStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of one or more snapshots. For example, <code>snap-1234567890abcdef0</code>. You can specify\n      a snapshot that was shared with you from another Amazon Web Services account.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "SourceSnapshotId"
@@ -34852,6 +36828,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -34896,6 +36874,7 @@
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AMI.</p>",
                         "smithy.api#required": {}
                     }
@@ -34903,6 +36882,7 @@
                 "DeprecateAt": {
                     "target": "com.amazonaws.ec2#MillisecondDateTime",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The date and time to deprecate the AMI, in UTC, in the following format:\n        <i>YYYY</i>-<i>MM</i>-<i>DD</i>T<i>HH</i>:<i>MM</i>:<i>SS</i>Z.\n      If you specify a value for seconds, Amazon EC2 rounds the seconds to the\n      nearest minute.</p>\n         <p>You can’t specify a date in the past. The upper limit for <code>DeprecateAt</code> is 10\n      years from now.</p>",
                         "smithy.api#required": {}
                     }
@@ -34910,6 +36890,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -34922,6 +36904,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -34946,12 +36930,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "DelegatedAdminAccountId": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Organizations member account ID that you want to enable as the IPAM account.</p>",
                         "smithy.api#required": {}
                     }
@@ -34965,6 +36952,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Success",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>The result of enabling the IPAM account.</p>",
                         "smithy.api#xmlName": "success"
                     }
@@ -34989,6 +36978,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -35001,6 +36992,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SerialConsoleAccessEnabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If <code>true</code>, access to the EC2 serial console of all instances is enabled for\n\t\t\tyour account. If <code>false</code>, access to the EC2 serial console of all instances\n\t\t\tis disabled for your account.</p>",
                         "smithy.api#xmlName": "serialConsoleAccessEnabled"
                     }
@@ -35025,6 +37018,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the propagation route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -35038,6 +37032,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -35080,6 +37076,7 @@
                 "GatewayId": {
                     "target": "com.amazonaws.ec2#VpnGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the virtual private gateway that is attached to a VPC. The virtual private\n            gateway must be attached to the same VPC that the routing tables are associated with.\n        </p>",
                         "smithy.api#required": {}
                     }
@@ -35087,6 +37084,7 @@
                 "RouteTableId": {
                     "target": "com.amazonaws.ec2#RouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the route table. The routing table must be associated with the same VPC that\n            the virtual private gateway is attached to. </p>",
                         "smithy.api#required": {}
                     }
@@ -35094,6 +37092,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -35121,6 +37121,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -35129,6 +37131,7 @@
                     "target": "com.amazonaws.ec2#VolumeId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VolumeId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the volume.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "volumeId"
@@ -35179,6 +37182,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -35192,6 +37197,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -35200,6 +37207,7 @@
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcId"
@@ -35214,6 +37222,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -35227,6 +37237,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Enabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If this parameter is set to <code>true</code>, the instance is enabled for Amazon Web Services Nitro Enclaves; otherwise, it is not enabled for Amazon Web Services Nitro\n            Enclaves.</p>",
                         "smithy.api#xmlName": "enabled"
                     }
@@ -35242,6 +37254,8 @@
                 "Enabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>To enable the instance for Amazon Web Services Nitro Enclaves, set this parameter to\n                <code>true</code>.</p>"
                     }
                 }
@@ -35251,24 +37265,23 @@
             }
         },
         "com.amazonaws.ec2#EncryptionInTransitSupported": {
-            "type": "boolean",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "boolean"
         },
         "com.amazonaws.ec2#EndDateType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "unlimited",
-                        "name": "unlimited"
-                    },
-                    {
-                        "value": "limited",
-                        "name": "limited"
+            "type": "enum",
+            "members": {
+                "unlimited": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unlimited"
                     }
-                ]
+                },
+                "limited": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "limited"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#EndpointSet": {
@@ -35281,22 +37294,26 @@
             }
         },
         "com.amazonaws.ec2#EphemeralNvmeSupport": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "unsupported",
-                        "name": "UNSUPPORTED"
-                    },
-                    {
-                        "value": "supported",
-                        "name": "SUPPORTED"
-                    },
-                    {
-                        "value": "required",
-                        "name": "REQUIRED"
+            "type": "enum",
+            "members": {
+                "UNSUPPORTED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unsupported"
                     }
-                ]
+                },
+                "SUPPORTED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "supported"
+                    }
+                },
+                "REQUIRED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "required"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ErrorSet": {
@@ -35309,30 +37326,38 @@
             }
         },
         "com.amazonaws.ec2#EventCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "instance-reboot",
-                        "name": "instance_reboot"
-                    },
-                    {
-                        "value": "system-reboot",
-                        "name": "system_reboot"
-                    },
-                    {
-                        "value": "system-maintenance",
-                        "name": "system_maintenance"
-                    },
-                    {
-                        "value": "instance-retirement",
-                        "name": "instance_retirement"
-                    },
-                    {
-                        "value": "instance-stop",
-                        "name": "instance_stop"
+            "type": "enum",
+            "members": {
+                "instance_reboot": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instance-reboot"
                     }
-                ]
+                },
+                "system_reboot": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "system-reboot"
+                    }
+                },
+                "system_maintenance": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "system-maintenance"
+                    }
+                },
+                "instance_retirement": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instance-retirement"
+                    }
+                },
+                "instance_stop": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instance-stop"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#EventInformation": {
@@ -35368,41 +37393,49 @@
             }
         },
         "com.amazonaws.ec2#EventType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "instanceChange",
-                        "name": "INSTANCE_CHANGE"
-                    },
-                    {
-                        "value": "fleetRequestChange",
-                        "name": "BATCH_CHANGE"
-                    },
-                    {
-                        "value": "error",
-                        "name": "ERROR"
-                    },
-                    {
-                        "value": "information",
-                        "name": "INFORMATION"
+            "type": "enum",
+            "members": {
+                "INSTANCE_CHANGE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instanceChange"
                     }
-                ]
+                },
+                "BATCH_CHANGE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fleetRequestChange"
+                    }
+                },
+                "ERROR": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "error"
+                    }
+                },
+                "INFORMATION": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "information"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ExcessCapacityTerminationPolicy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "noTermination",
-                        "name": "NO_TERMINATION"
-                    },
-                    {
-                        "value": "default",
-                        "name": "DEFAULT"
+            "type": "enum",
+            "members": {
+                "NO_TERMINATION": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "noTermination"
                     }
-                ]
+                },
+                "DEFAULT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "default"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ExcludedInstanceType": {
@@ -35582,6 +37615,8 @@
                     "target": "com.amazonaws.ec2#Port",
                     "traits": {
                         "aws.protocols#ec2QueryName": "LoadBalancerListenerPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The listener port of the load balancer.</p>",
                         "smithy.api#xmlName": "loadBalancerListenerPort"
                     }
@@ -35614,6 +37649,8 @@
                     "target": "com.amazonaws.ec2#Port",
                     "traits": {
                         "aws.protocols#ec2QueryName": "LoadBalancerTargetPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The target port.</p>",
                         "smithy.api#xmlName": "loadBalancerTargetPort"
                     }
@@ -35670,6 +37707,8 @@
                     "target": "com.amazonaws.ec2#Port",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Port",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The port.</p>",
                         "smithy.api#xmlName": "port"
                     }
@@ -35866,6 +37905,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint.</p>",
                         "smithy.api#required": {}
                     }
@@ -35873,6 +37913,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -35917,6 +37959,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint.</p>",
                         "smithy.api#required": {}
                     }
@@ -35924,6 +37967,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -35943,22 +37988,26 @@
             }
         },
         "com.amazonaws.ec2#ExportEnvironment": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "citrix",
-                        "name": "citrix"
-                    },
-                    {
-                        "value": "vmware",
-                        "name": "vmware"
-                    },
-                    {
-                        "value": "microsoft",
-                        "name": "microsoft"
+            "type": "enum",
+            "members": {
+                "citrix": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "citrix"
                     }
-                ]
+                },
+                "vmware": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vmware"
+                    }
+                },
+                "microsoft": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "microsoft"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ExportImage": {
@@ -35992,6 +38041,7 @@
                 "DiskImageFormat": {
                     "target": "com.amazonaws.ec2#DiskImageFormat",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The disk image format.</p>",
                         "smithy.api#required": {}
                     }
@@ -35999,12 +38049,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the image.</p>",
                         "smithy.api#required": {}
                     }
@@ -36012,6 +38065,7 @@
                 "S3ExportLocation": {
                     "target": "com.amazonaws.ec2#ExportTaskS3LocationRequest",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Amazon S3 bucket for the destination image. The destination bucket must exist.</p>",
                         "smithy.api#required": {}
                     }
@@ -36324,6 +38378,7 @@
                 "S3Bucket": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The destination Amazon S3 bucket.</p>",
                         "smithy.api#required": {}
                     }
@@ -36340,26 +38395,32 @@
             }
         },
         "com.amazonaws.ec2#ExportTaskState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "cancelling",
-                        "name": "cancelling"
-                    },
-                    {
-                        "value": "cancelled",
-                        "name": "cancelled"
-                    },
-                    {
-                        "value": "completed",
-                        "name": "completed"
+            "type": "enum",
+            "members": {
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
                     }
-                ]
+                },
+                "cancelling": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelling"
+                    }
+                },
+                "cancelled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelled"
+                    }
+                },
+                "completed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "completed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ExportToS3Task": {
@@ -36460,6 +38521,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -36474,6 +38536,7 @@
                 "S3Bucket": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The name of the S3 bucket.</p>",
                         "smithy.api#required": {}
                     }
@@ -36481,6 +38544,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -36595,6 +38660,7 @@
                 "Version": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The version of the launch template to use for faster launching for a Windows AMI.</p>",
                         "smithy.api#required": {}
                     }
@@ -36637,14 +38703,14 @@
             }
         },
         "com.amazonaws.ec2#FastLaunchResourceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "snapshot",
-                        "name": "SNAPSHOT"
+            "type": "enum",
+            "members": {
+                "SNAPSHOT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "snapshot"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#FastLaunchSnapshotConfigurationRequest": {
@@ -36653,6 +38719,8 @@
                 "TargetResourceCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of pre-provisioned snapshots to keep on hand for a fast-launch enabled Windows AMI.</p>"
                     }
                 }
@@ -36668,6 +38736,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TargetResourceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of pre-provisioned snapshots requested to keep on hand for a fast-launch enabled Windows AMI.</p>",
                         "smithy.api#xmlName": "targetResourceCount"
                     }
@@ -36678,61 +38748,79 @@
             }
         },
         "com.amazonaws.ec2#FastLaunchStateCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enabling",
-                        "name": "enabling"
-                    },
-                    {
-                        "value": "enabling-failed",
-                        "name": "enabling_failed"
-                    },
-                    {
-                        "value": "enabled",
-                        "name": "enabled"
-                    },
-                    {
-                        "value": "enabled-failed",
-                        "name": "enabled_failed"
-                    },
-                    {
-                        "value": "disabling",
-                        "name": "disabling"
-                    },
-                    {
-                        "value": "disabling-failed",
-                        "name": "disabling_failed"
+            "type": "enum",
+            "members": {
+                "enabling": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabling"
                     }
-                ]
+                },
+                "enabling_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabling-failed"
+                    }
+                },
+                "enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled"
+                    }
+                },
+                "enabled_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled-failed"
+                    }
+                },
+                "disabling": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabling"
+                    }
+                },
+                "disabling_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabling-failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FastSnapshotRestoreStateCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enabling",
-                        "name": "enabling"
-                    },
-                    {
-                        "value": "optimizing",
-                        "name": "optimizing"
-                    },
-                    {
-                        "value": "enabled",
-                        "name": "enabled"
-                    },
-                    {
-                        "value": "disabling",
-                        "name": "disabling"
-                    },
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
+            "type": "enum",
+            "members": {
+                "enabling": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabling"
                     }
-                ]
+                },
+                "optimizing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "optimizing"
+                    }
+                },
+                "enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled"
+                    }
+                },
+                "disabling": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabling"
+                    }
+                },
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FederatedAuthentication": {
@@ -36810,45 +38898,55 @@
             }
         },
         "com.amazonaws.ec2#FindingsFound": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "true",
-                        "name": "true"
-                    },
-                    {
-                        "value": "false",
-                        "name": "false"
-                    },
-                    {
-                        "value": "unknown",
-                        "name": "unknown"
+            "type": "enum",
+            "members": {
+                "true": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "true"
                     }
-                ]
+                },
+                "false": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "false"
+                    }
+                },
+                "unknown": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unknown"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FleetActivityStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "error",
-                        "name": "ERROR"
-                    },
-                    {
-                        "value": "pending_fulfillment",
-                        "name": "PENDING_FULFILLMENT"
-                    },
-                    {
-                        "value": "pending_termination",
-                        "name": "PENDING_TERMINATION"
-                    },
-                    {
-                        "value": "fulfilled",
-                        "name": "FULFILLED"
+            "type": "enum",
+            "members": {
+                "ERROR": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "error"
                     }
-                ]
+                },
+                "PENDING_FULFILLMENT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending_fulfillment"
+                    }
+                },
+                "PENDING_TERMINATION": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending_termination"
+                    }
+                },
+                "FULFILLED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fulfilled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FleetCapacityReservation": {
@@ -36898,6 +38996,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalInstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of instances for which the Capacity Reservation reserves capacity.</p>",
                         "smithy.api#xmlName": "totalInstanceCount"
                     }
@@ -36906,6 +39006,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FulfilledCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of capacity units fulfilled by the Capacity Reservation. For more information, see \n\t\t\t<a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/crfleet-concepts.html#target-capacity\">\n\t\t\t\tTotal target capacity</a> in the Amazon EC2 User Guide.</p>",
                         "smithy.api#xmlName": "fulfilledCapacity"
                     }
@@ -36914,6 +39016,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EbsOptimized",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the Capacity Reservation reserves capacity for EBS-optimized instance types.</p>",
                         "smithy.api#xmlName": "ebsOptimized"
                     }
@@ -36957,25 +39061,25 @@
             }
         },
         "com.amazonaws.ec2#FleetCapacityReservationTenancy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "default",
-                        "name": "default"
+            "type": "enum",
+            "members": {
+                "default": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "default"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#FleetCapacityReservationUsageStrategy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "use-capacity-reservations-first",
-                        "name": "USE_CAPACITY_RESERVATIONS_FIRST"
+            "type": "enum",
+            "members": {
+                "USE_CAPACITY_RESERVATIONS_FIRST": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "use-capacity-reservations-first"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#FleetData": {
@@ -37033,6 +39137,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FulfilledCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of units fulfilled by this request compared to the set target\n         capacity.</p>",
                         "smithy.api#xmlName": "fulfilledCapacity"
                     }
@@ -37041,6 +39147,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FulfilledOnDemandCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of units fulfilled by this request compared to the set target On-Demand\n         capacity.</p>",
                         "smithy.api#xmlName": "fulfilledOnDemandCapacity"
                     }
@@ -37065,6 +39173,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TerminateInstancesWithExpiration",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether running instances should be terminated when the EC2 Fleet expires. </p>",
                         "smithy.api#xmlName": "terminateInstancesWithExpiration"
                     }
@@ -37097,6 +39207,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ReplaceUnhealthyInstances",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether EC2 Fleet should replace unhealthy Spot Instances. Supported only for\n         fleets of type <code>maintain</code>. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/manage-ec2-fleet.html#ec2-fleet-health-checks\">EC2 Fleet\n            health checks</a> in the <i>Amazon EC2 User Guide</i>.</p>",
                         "smithy.api#xmlName": "replaceUnhealthyInstances"
                     }
@@ -37155,37 +39267,43 @@
             }
         },
         "com.amazonaws.ec2#FleetEventType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "instance-change",
-                        "name": "INSTANCE_CHANGE"
-                    },
-                    {
-                        "value": "fleet-change",
-                        "name": "FLEET_CHANGE"
-                    },
-                    {
-                        "value": "service-error",
-                        "name": "SERVICE_ERROR"
+            "type": "enum",
+            "members": {
+                "INSTANCE_CHANGE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instance-change"
                     }
-                ]
+                },
+                "FLEET_CHANGE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fleet-change"
+                    }
+                },
+                "SERVICE_ERROR": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "service-error"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FleetExcessCapacityTerminationPolicy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "no-termination",
-                        "name": "NO_TERMINATION"
-                    },
-                    {
-                        "value": "termination",
-                        "name": "TERMINATION"
+            "type": "enum",
+            "members": {
+                "NO_TERMINATION": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "no-termination"
                     }
-                ]
+                },
+                "TERMINATION": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "termination"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FleetId": {
@@ -37198,14 +39316,14 @@
             }
         },
         "com.amazonaws.ec2#FleetInstanceMatchCriteria": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "open",
-                        "name": "open"
+            "type": "enum",
+            "members": {
+                "open": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "open"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#FleetLaunchTemplateConfig": {
@@ -37315,6 +39433,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "WeightedCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of units provided by the specified instance type.</p>",
                         "smithy.api#xmlName": "weightedCapacity"
                     }
@@ -37323,6 +39443,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Priority",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The priority for the launch template override. The highest priority is launched\n         first.</p>\n         <p>If the On-Demand <code>AllocationStrategy</code> is set to <code>prioritized</code>,\n         EC2 Fleet uses priority to determine which launch template override to use first in fulfilling\n         On-Demand capacity.</p>\n         <p>If the Spot <code>AllocationStrategy</code> is set to\n            <code>capacity-optimized-prioritized</code>, EC2 Fleet uses priority on a best-effort basis\n         to determine which launch template override to use in fulfilling Spot capacity, but\n         optimizes for capacity first.</p>\n         <p>Valid values are whole numbers starting at <code>0</code>. The lower the number, the\n         higher the priority. If no number is set, the override has the lowest priority. You can set\n         the same priority for different launch template overrides.</p>",
                         "smithy.api#xmlName": "priority"
                     }
@@ -37396,12 +39518,16 @@
                 "WeightedCapacity": {
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of units provided by the specified instance type.</p>"
                     }
                 },
                 "Priority": {
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The priority for the launch template override. The highest priority is launched\n         first.</p>\n         <p>If the On-Demand <code>AllocationStrategy</code> is set to <code>prioritized</code>,\n         EC2 Fleet uses priority to determine which launch template override to use first in fulfilling\n         On-Demand capacity.</p>\n         <p>If the Spot <code>AllocationStrategy</code> is set to\n            <code>capacity-optimized-prioritized</code>, EC2 Fleet uses priority on a best-effort basis\n         to determine which launch template override to use in fulfilling Spot capacity, but\n         optimizes for capacity first.</p>\n         <p>Valid values are whole numbers starting at <code>0</code>. The lower the number, the\n         higher the priority. If no number is set, the launch template override has the lowest\n         priority. You can set the same priority for different launch template overrides.</p>"
                     }
                 },
@@ -37481,33 +39607,37 @@
             }
         },
         "com.amazonaws.ec2#FleetOnDemandAllocationStrategy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "lowest-price",
-                        "name": "LOWEST_PRICE"
-                    },
-                    {
-                        "value": "prioritized",
-                        "name": "PRIORITIZED"
+            "type": "enum",
+            "members": {
+                "LOWEST_PRICE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "lowest-price"
                     }
-                ]
+                },
+                "PRIORITIZED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "prioritized"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FleetReplacementStrategy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "launch",
-                        "name": "LAUNCH"
-                    },
-                    {
-                        "value": "launch-before-terminate",
-                        "name": "LAUNCH_BEFORE_TERMINATE"
+            "type": "enum",
+            "members": {
+                "LAUNCH": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launch"
                     }
-                ]
+                },
+                "LAUNCH_BEFORE_TERMINATE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launch-before-terminate"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FleetSet": {
@@ -37534,6 +39664,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TerminationDelay",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The amount of time (in seconds) that Amazon EC2 waits before terminating the old Spot\n         Instance after launching a new replacement Spot Instance.</p>\n         <p>Required when <code>ReplacementStrategy</code> is set to <code>launch-before-terminate</code>.</p>\n         <p>Not valid when <code>ReplacementStrategy</code> is set to <code>launch</code>.</p>\n         <p>Valid values: Minimum value of <code>120</code> seconds. Maximum value of <code>7200</code> seconds.</p>",
                         "smithy.api#xmlName": "terminationDelay"
                     }
@@ -37555,6 +39687,8 @@
                 "TerminationDelay": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The amount of time (in seconds) that Amazon EC2 waits before terminating the old Spot\n         Instance after launching a new replacement Spot Instance.</p>\n         <p>Required when <code>ReplacementStrategy</code> is set to <code>launch-before-terminate</code>.</p>\n         <p>Not valid when <code>ReplacementStrategy</code> is set to <code>launch</code>.</p>\n         <p>Valid values: Minimum value of <code>120</code> seconds. Maximum value of <code>7200</code> seconds.</p>"
                     }
                 }
@@ -37594,61 +39728,80 @@
             }
         },
         "com.amazonaws.ec2#FleetStateCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "submitted",
-                        "name": "SUBMITTED"
-                    },
-                    {
-                        "value": "active",
-                        "name": "ACTIVE"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "DELETED"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "FAILED"
-                    },
-                    {
-                        "value": "deleted_running",
-                        "name": "DELETED_RUNNING"
-                    },
-                    {
-                        "value": "deleted_terminating",
-                        "name": "DELETED_TERMINATING_INSTANCES"
-                    },
-                    {
-                        "value": "modifying",
-                        "name": "MODIFYING"
+            "type": "enum",
+            "members": {
+                "SUBMITTED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "submitted"
                     }
-                ]
+                },
+                "ACTIVE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "DELETED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                },
+                "FAILED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "DELETED_RUNNING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted_running"
+                    }
+                },
+                "DELETED_TERMINATING_INSTANCES": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted_terminating"
+                    }
+                },
+                "MODIFYING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modifying"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FleetType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "request",
-                        "name": "REQUEST"
-                    },
-                    {
-                        "value": "maintain",
-                        "name": "MAINTAIN"
-                    },
-                    {
-                        "value": "instant",
-                        "name": "INSTANT"
+            "type": "enum",
+            "members": {
+                "REQUEST": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "request"
                     }
-                ]
+                },
+                "MAINTAIN": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "maintain"
+                    }
+                },
+                "INSTANT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instant"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#Float": {
-            "type": "float"
+            "type": "float",
+            "traits": {
+                "smithy.api#default": 0
+            }
         },
         "com.amazonaws.ec2#FlowLog": {
             "type": "structure",
@@ -37769,6 +39922,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxAggregationInterval",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum interval of time, in seconds, during which a flow of packets is captured and aggregated into a flow log record.</p>\n        <p>When a network interface is attached to a <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html#ec2-nitro-instances\">Nitro-based\n                instance</a>, the aggregation interval is always 60 seconds (1 minute) or less,\n            regardless of the specified value.</p>\n        <p>Valid Values: <code>60</code> | <code>600</code>\n         </p>",
                         "smithy.api#xmlName": "maxAggregationInterval"
                     }
@@ -37817,37 +39972,42 @@
             }
         },
         "com.amazonaws.ec2#FlowLogsResourceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "VPC",
-                        "name": "VPC"
-                    },
-                    {
-                        "value": "Subnet",
-                        "name": "Subnet"
-                    },
-                    {
-                        "value": "NetworkInterface",
-                        "name": "NetworkInterface"
-                    },
-                    {
-                        "value": "TransitGateway",
-                        "name": "TransitGateway"
-                    },
-                    {
-                        "value": "TransitGatewayAttachment",
-                        "name": "TransitGatewayAttachment"
+            "type": "enum",
+            "members": {
+                "VPC": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "VPC"
                     }
-                ]
+                },
+                "Subnet": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Subnet"
+                    }
+                },
+                "NetworkInterface": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "NetworkInterface"
+                    }
+                },
+                "TransitGateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "TransitGateway"
+                    }
+                },
+                "TransitGatewayAttachment": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "TransitGatewayAttachment"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FpgaDeviceCount": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#FpgaDeviceInfo": {
             "type": "structure",
@@ -37918,10 +40078,7 @@
             }
         },
         "com.amazonaws.ec2#FpgaDeviceMemorySize": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#FpgaDeviceName": {
             "type": "string"
@@ -38037,6 +40194,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Public",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the AFI is public.</p>",
                         "smithy.api#xmlName": "public"
                     }
@@ -38045,6 +40204,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DataRetentionSupport",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether data retention support is enabled for the AFI.</p>",
                         "smithy.api#xmlName": "dataRetentionSupport"
                     }
@@ -38103,26 +40264,32 @@
             }
         },
         "com.amazonaws.ec2#FpgaImageAttributeName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "description",
-                        "name": "description"
-                    },
-                    {
-                        "value": "name",
-                        "name": "name"
-                    },
-                    {
-                        "value": "loadPermission",
-                        "name": "loadPermission"
-                    },
-                    {
-                        "value": "productCodes",
-                        "name": "productCodes"
+            "type": "enum",
+            "members": {
+                "description": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "description"
                     }
-                ]
+                },
+                "name": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "name"
+                    }
+                },
+                "loadPermission": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "loadPermission"
+                    }
+                },
+                "productCodes": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "productCodes"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FpgaImageId": {
@@ -38171,26 +40338,32 @@
             }
         },
         "com.amazonaws.ec2#FpgaImageStateCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "unavailable",
-                        "name": "unavailable"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "unavailable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unavailable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#FpgaInfo": {
@@ -38218,15 +40391,11 @@
             }
         },
         "com.amazonaws.ec2#FreeTierEligibleFlag": {
-            "type": "boolean",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "boolean"
         },
         "com.amazonaws.ec2#GVCDMaxResults": {
             "type": "integer",
             "traits": {
-                "smithy.api#box": {},
                 "smithy.api#range": {
                     "min": 200,
                     "max": 1000
@@ -38234,37 +40403,43 @@
             }
         },
         "com.amazonaws.ec2#GatewayAssociationState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "associated",
-                        "name": "associated"
-                    },
-                    {
-                        "value": "not-associated",
-                        "name": "not_associated"
-                    },
-                    {
-                        "value": "associating",
-                        "name": "associating"
-                    },
-                    {
-                        "value": "disassociating",
-                        "name": "disassociating"
+            "type": "enum",
+            "members": {
+                "associated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associated"
                     }
-                ]
+                },
+                "not_associated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "not-associated"
+                    }
+                },
+                "associating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associating"
+                    }
+                },
+                "disassociating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociating"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#GatewayType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ipsec.1",
-                        "name": "ipsec_1"
+            "type": "enum",
+            "members": {
+                "ipsec_1": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipsec.1"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#GetAssociatedEnclaveCertificateIamRoles": {
@@ -38291,6 +40466,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -38333,6 +40510,7 @@
                 "PoolId": {
                     "target": "com.amazonaws.ec2#Ipv6PoolEc2Id",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPv6 address pool.</p>",
                         "smithy.api#required": {}
                     }
@@ -38346,12 +40524,16 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Ipv6PoolMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -38396,6 +40578,7 @@
                 "CapacityReservationId": {
                     "target": "com.amazonaws.ec2#CapacityReservationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Capacity Reservation.</p>",
                         "smithy.api#required": {}
                     }
@@ -38409,12 +40592,16 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#GetCapacityReservationUsageRequestMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the returned <code>nextToken</code> value. This value can be between 5 and 500. If <code>maxResults</code> is given a larger value than 500, you receive an error.</p>\n\t\t       <p>Valid range: Minimum value of 1. Maximum value of 1000.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -38423,6 +40610,7 @@
         "com.amazonaws.ec2#GetCapacityReservationUsageRequestMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 1000
@@ -38460,6 +40648,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalInstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of instances for which the Capacity Reservation reserves capacity.</p>",
                         "smithy.api#xmlName": "totalInstanceCount"
                     }
@@ -38468,6 +40658,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AvailableInstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The remaining capacity. Indicates the number of instances that can be launched in the Capacity Reservation.</p>",
                         "smithy.api#xmlName": "availableInstanceCount"
                     }
@@ -38508,6 +40700,7 @@
                 "PoolId": {
                     "target": "com.amazonaws.ec2#Ipv4PoolCoipId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the address pool.</p>",
                         "smithy.api#required": {}
                     }
@@ -38522,6 +40715,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#CoipPoolMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -38534,6 +40729,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -38586,6 +40783,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {}
                     }
@@ -38594,6 +40792,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -38601,6 +40801,8 @@
                 "Latest": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>When enabled, retrieves the latest console output for the instance.</p>\n        <p>Default: disabled (<code>false</code>)</p>"
                     }
                 }
@@ -38653,12 +40855,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {}
                     }
@@ -38666,6 +40871,8 @@
                 "WakeUp": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>When set to <code>true</code>, acts as keystroke input and wakes up an instance that's\n            in standby or \"sleep\" mode.</p>"
                     }
                 }
@@ -38710,12 +40917,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "InstanceFamily": {
                     "target": "com.amazonaws.ec2#UnlimitedSupportedInstanceFamily",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The instance family.</p>",
                         "smithy.api#required": {}
                     }
@@ -38753,6 +40963,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -38789,6 +41001,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -38801,6 +41015,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EbsEncryptionByDefault",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether encryption by default is enabled.</p>",
                         "smithy.api#xmlName": "ebsEncryptionByDefault"
                     }
@@ -38825,12 +41041,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "FlowLogId": {
                     "target": "com.amazonaws.ec2#VpcFlowLogId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the flow log.</p>",
                         "smithy.api#required": {}
                     }
@@ -38838,6 +41057,7 @@
                 "ConfigDeliveryS3DestinationArn": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>To store the CloudFormation template in Amazon S3, specify the location in Amazon S3.</p>",
                         "smithy.api#required": {}
                     }
@@ -38845,6 +41065,7 @@
                 "IntegrateServices": {
                     "target": "com.amazonaws.ec2#IntegrateServices",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Information about the service integration.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "IntegrateService"
@@ -38889,6 +41110,7 @@
                 "CapacityReservationId": {
                     "target": "com.amazonaws.ec2#CapacityReservationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Capacity Reservation.</p>",
                         "smithy.api#required": {}
                     }
@@ -38902,12 +41124,16 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#GetGroupsForCapacityReservationRequestMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return for the request in a single page. The remaining results can be seen by sending another request with the returned <code>nextToken</code> value. This value can be between 5 and 500. If <code>maxResults</code> is given a larger value than 500, you receive an error.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -38916,6 +41142,7 @@
         "com.amazonaws.ec2#GetGroupsForCapacityReservationRequestMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 1000
@@ -38961,6 +41188,7 @@
                 "HostIdSet": {
                     "target": "com.amazonaws.ec2#RequestHostIdSet",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the Dedicated Hosts with which the reservation is associated.</p>",
                         "smithy.api#required": {}
                     }
@@ -38968,6 +41196,7 @@
                 "OfferingId": {
                     "target": "com.amazonaws.ec2#OfferingId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The offering ID of the reservation.</p>",
                         "smithy.api#required": {}
                     }
@@ -39035,12 +41264,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ArchitectureTypes": {
                     "target": "com.amazonaws.ec2#ArchitectureTypeSet",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The processor architecture type.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ArchitectureType"
@@ -39049,6 +41281,7 @@
                 "VirtualizationTypes": {
                     "target": "com.amazonaws.ec2#VirtualizationTypeSet",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The virtualization type.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "VirtualizationType"
@@ -39057,6 +41290,7 @@
                 "InstanceRequirements": {
                     "target": "com.amazonaws.ec2#InstanceRequirementsRequest",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The attributes required for the instance types.</p>",
                         "smithy.api#required": {}
                     }
@@ -39064,6 +41298,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. Specify a value between 1 and\u2028 \n         1000. The default value is 1000. To retrieve the remaining results, make another call with\u2028 \n         the returned <code>NextToken</code> value.</p>"
                     }
                 },
@@ -39114,6 +41350,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance from which to retrieve the UEFI data.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "InstanceId"
@@ -39122,6 +41359,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -39172,12 +41411,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR you want the history of. The CIDR can be an IPv4 or IPv6 IP address range. \n         If you enter a /16 IPv4 CIDR, you will get records that match it exactly. You will not get records for any subnets within the /16 CIDR.</p>",
                         "smithy.api#required": {}
                     }
@@ -39185,6 +41427,7 @@
                 "IpamScopeId": {
                     "target": "com.amazonaws.ec2#IpamScopeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPAM scope that the CIDR is in.</p>",
                         "smithy.api#required": {}
                     }
@@ -39210,6 +41453,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#IpamAddressHistoryMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of historical results you would like returned per page. Defaults to 100.</p>"
                     }
                 },
@@ -39263,6 +41508,7 @@
         "com.amazonaws.ec2#GetIpamPoolAllocationsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1000,
                     "max": 100000
@@ -39275,12 +41521,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamPoolId": {
                     "target": "com.amazonaws.ec2#IpamPoolId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPAM pool you want to see the allocations for.</p>",
                         "smithy.api#required": {}
                     }
@@ -39301,6 +41550,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#GetIpamPoolAllocationsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results you would like returned per page.</p>"
                     }
                 },
@@ -39357,12 +41608,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamPoolId": {
                     "target": "com.amazonaws.ec2#IpamPoolId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPAM pool you want the CIDR for.</p>",
                         "smithy.api#required": {}
                     }
@@ -39377,6 +41631,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#IpamMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in the request.</p>"
                     }
                 },
@@ -39433,6 +41689,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -39446,6 +41704,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#IpamMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in the request.</p>"
                     }
                 },
@@ -39458,6 +41718,7 @@
                 "IpamScopeId": {
                     "target": "com.amazonaws.ec2#IpamScopeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the scope that the resource is in.</p>",
                         "smithy.api#required": {}
                     }
@@ -39530,12 +41791,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {}
                     }
@@ -39576,6 +41840,7 @@
         "com.amazonaws.ec2#GetManagedPrefixListAssociationsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 255
@@ -39588,12 +41853,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "PrefixListId": {
                     "target": "com.amazonaws.ec2#PrefixListResourceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the prefix list.</p>",
                         "smithy.api#required": {}
                     }
@@ -39601,6 +41869,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#GetManagedPrefixListAssociationsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -39657,12 +41927,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "PrefixListId": {
                     "target": "com.amazonaws.ec2#PrefixListResourceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the prefix list.</p>",
                         "smithy.api#required": {}
                     }
@@ -39670,12 +41943,16 @@
                 "TargetVersion": {
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The version of the prefix list for which to return the entries. The default is the current version.</p>"
                     }
                 },
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#PrefixListMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -39726,6 +42003,7 @@
                 "NetworkInsightsAccessScopeAnalysisId": {
                     "target": "com.amazonaws.ec2#NetworkInsightsAccessScopeAnalysisId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Network Access Scope analysis.</p>",
                         "smithy.api#required": {}
                     }
@@ -39733,6 +42011,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#NetworkInsightsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n   To retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -39745,6 +42025,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -39805,6 +42087,7 @@
                 "NetworkInsightsAccessScopeId": {
                     "target": "com.amazonaws.ec2#NetworkInsightsAccessScopeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Network Access Scope.</p>",
                         "smithy.api#required": {}
                     }
@@ -39812,6 +42095,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -39865,6 +42150,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Windows instance.</p>",
                         "smithy.api#required": {}
                     }
@@ -39873,6 +42159,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -39926,12 +42214,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n      and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n      Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ReservedInstanceIds": {
                     "target": "com.amazonaws.ec2#ReservedInstanceIdSet",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the Convertible Reserved Instances to exchange.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ReservedInstanceId"
@@ -39964,6 +42255,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "IsValidExchange",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If <code>true</code>, the exchange is valid. If <code>false</code>, the exchange cannot be completed.</p>",
                         "smithy.api#xmlName": "isValidExchange"
                     }
@@ -40047,6 +42340,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -40059,6 +42354,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SerialConsoleAccessEnabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If <code>true</code>, access to the EC2 serial console of all instances is enabled for\n\t\t\tyour account. If <code>false</code>, access to the EC2 serial console of all instances\n\t\t\tis disabled for your account.</p>",
                         "smithy.api#xmlName": "serialConsoleAccessEnabled"
                     }
@@ -40096,6 +42393,8 @@
                 "TargetCapacity": {
                     "target": "com.amazonaws.ec2#SpotPlacementScoresTargetCapacity",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The target capacity.</p>",
                         "smithy.api#required": {}
                     }
@@ -40109,6 +42408,8 @@
                 "SingleAvailabilityZone": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specify <code>true</code> so that the response returns a list of scored Availability Zones.\n         Otherwise, the response returns a list of scored Regions.</p>\n         <p>A list of scored Availability Zones is useful if you want to launch all of your Spot\n         capacity into a single Availability Zone.</p>"
                     }
                 },
@@ -40128,12 +42429,16 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#SpotPlacementScoresMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return in a single call. Specify a value between 1 and\u2028      \n      1000. The default value is 1000. To retrieve the remaining results, make another call with\u2028      \n      the returned <code>NextToken</code> value.</p>"
                     }
                 },
@@ -40181,6 +42486,7 @@
         "com.amazonaws.ec2#GetSubnetCidrReservationsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -40200,6 +42506,7 @@
                 "SubnetId": {
                     "target": "com.amazonaws.ec2#SubnetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the subnet.</p>",
                         "smithy.api#required": {}
                     }
@@ -40207,6 +42514,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -40219,6 +42528,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#GetSubnetCidrReservationsMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 }
@@ -40277,6 +42588,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -40291,6 +42603,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -40303,6 +42617,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -40366,6 +42682,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -40378,6 +42696,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -40428,6 +42748,7 @@
                 "TransitGatewayPolicyTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayPolicyTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway policy table.</p>",
                         "smithy.api#required": {}
                     }
@@ -40442,6 +42763,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -40454,6 +42777,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -40498,6 +42823,7 @@
                 "TransitGatewayPolicyTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayPolicyTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway policy table.</p>",
                         "smithy.api#required": {}
                     }
@@ -40512,6 +42838,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -40524,6 +42852,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -40566,6 +42896,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -40580,6 +42911,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -40592,6 +42925,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -40642,6 +42977,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -40656,6 +42992,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -40668,6 +43006,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -40718,6 +43058,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -40732,6 +43073,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -40744,6 +43087,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -40788,6 +43133,7 @@
                 "VpnConnectionId": {
                     "target": "com.amazonaws.ec2#VpnConnectionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The <code>VpnConnectionId</code> specifies the Site-to-Site VPN connection used for the sample\n            configuration.</p>",
                         "smithy.api#required": {}
                     }
@@ -40795,6 +43141,7 @@
                 "VpnConnectionDeviceTypeId": {
                     "target": "com.amazonaws.ec2#VpnConnectionDeviceTypeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Device identifier provided by the <code>GetVpnConnectionDeviceTypes</code> API.</p>",
                         "smithy.api#required": {}
                     }
@@ -40808,6 +43155,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -40862,6 +43211,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -40889,10 +43240,7 @@
             }
         },
         "com.amazonaws.ec2#GpuDeviceCount": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#GpuDeviceInfo": {
             "type": "structure",
@@ -40963,10 +43311,7 @@
             }
         },
         "com.amazonaws.ec2#GpuDeviceMemorySize": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#GpuDeviceName": {
             "type": "string"
@@ -41065,10 +43410,7 @@
             }
         },
         "com.amazonaws.ec2#HibernationFlag": {
-            "type": "boolean",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "boolean"
         },
         "com.amazonaws.ec2#HibernationOptions": {
             "type": "structure",
@@ -41077,6 +43419,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Configured",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If this parameter is set to <code>true</code>, your instance is enabled for\n            hibernation; otherwise, it is not enabled for hibernation.</p>",
                         "smithy.api#xmlName": "configured"
                     }
@@ -41092,6 +43436,8 @@
                 "Configured": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If you set this parameter to <code>true</code>, your instance is enabled for\n            hibernation.</p>\n        <p>Default: <code>false</code>\n         </p>"
                     }
                 }
@@ -41317,6 +43663,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MemberOfServiceLinkedResourceGroup",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the Dedicated Host is in a host resource group. If \n\t\t\t<b>memberOfServiceLinkedResourceGroup</b> is \n\t\t\t<code>true</code>, the host is in a host resource group; otherwise, it is not.</p>",
                         "smithy.api#xmlName": "memberOfServiceLinkedResourceGroup"
                     }
@@ -41399,6 +43747,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Duration",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The duration of the offering (in seconds).</p>",
                         "smithy.api#xmlName": "duration"
                     }
@@ -41464,6 +43814,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Cores",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of cores on the Dedicated Host.</p>",
                         "smithy.api#xmlName": "cores"
                     }
@@ -41488,6 +43840,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Sockets",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of sockets on the Dedicated Host.</p>",
                         "smithy.api#xmlName": "sockets"
                     }
@@ -41496,6 +43850,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalVCpus",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of vCPUs on the Dedicated Host.</p>",
                         "smithy.api#xmlName": "totalVCpus"
                     }
@@ -41506,18 +43862,20 @@
             }
         },
         "com.amazonaws.ec2#HostRecovery": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "on",
-                        "name": "on"
-                    },
-                    {
-                        "value": "off",
-                        "name": "off"
+            "type": "enum",
+            "members": {
+                "on": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "on"
                     }
-                ]
+                },
+                "off": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "off"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#HostReservation": {
@@ -41527,6 +43885,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Count",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of Dedicated Hosts the reservation is associated with.</p>",
                         "smithy.api#xmlName": "count"
                     }
@@ -41543,6 +43903,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Duration",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The length of the reservation's term, specified in seconds. Can be <code>31536000\n                (1 year)</code> | <code>94608000 (3 years)</code>.</p>",
                         "smithy.api#xmlName": "duration"
                     }
@@ -41662,38 +44024,43 @@
             }
         },
         "com.amazonaws.ec2#HostTenancy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "dedicated",
-                        "name": "dedicated"
-                    },
-                    {
-                        "value": "host",
-                        "name": "host"
+            "type": "enum",
+            "members": {
+                "dedicated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "dedicated"
                     }
-                ]
+                },
+                "host": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "host"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#HostnameType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ip-name",
-                        "name": "ip_name"
-                    },
-                    {
-                        "value": "resource-name",
-                        "name": "resource_name"
+            "type": "enum",
+            "members": {
+                "ip_name": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ip-name"
                     }
-                ]
+                },
+                "resource_name": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "resource-name"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#Hour": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 0,
                     "max": 23
@@ -41701,33 +44068,37 @@
             }
         },
         "com.amazonaws.ec2#HttpTokensState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "optional",
-                        "name": "optional"
-                    },
-                    {
-                        "value": "required",
-                        "name": "required"
+            "type": "enum",
+            "members": {
+                "optional": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "optional"
                     }
-                ]
+                },
+                "required": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "required"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#HypervisorType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ovm",
-                        "name": "ovm"
-                    },
-                    {
-                        "value": "xen",
-                        "name": "xen"
+            "type": "enum",
+            "members": {
+                "ovm": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ovm"
                     }
-                ]
+                },
+                "xen": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "xen"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IKEVersionsList": {
@@ -41863,26 +44234,32 @@
             }
         },
         "com.amazonaws.ec2#IamInstanceProfileAssociationState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "associating",
-                        "name": "ASSOCIATING"
-                    },
-                    {
-                        "value": "associated",
-                        "name": "ASSOCIATED"
-                    },
-                    {
-                        "value": "disassociating",
-                        "name": "DISASSOCIATING"
-                    },
-                    {
-                        "value": "disassociated",
-                        "name": "DISASSOCIATED"
+            "type": "enum",
+            "members": {
+                "ASSOCIATING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associating"
                     }
-                ]
+                },
+                "ASSOCIATED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associated"
+                    }
+                },
+                "DISASSOCIATING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociating"
+                    }
+                },
+                "DISASSOCIATED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociated"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IamInstanceProfileSpecification": {
@@ -41916,6 +44293,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Code",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The ICMP code. A value of -1 means all codes for the specified ICMP type.</p>",
                         "smithy.api#xmlName": "code"
                     }
@@ -41924,6 +44303,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Type",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The ICMP type. A value of -1 means all types.</p>",
                         "smithy.api#xmlName": "type"
                     }
@@ -41956,6 +44337,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "UseLongIds",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether longer IDs (17-character IDs) are enabled for the resource.</p>",
                         "smithy.api#xmlName": "useLongIds"
                     }
@@ -41975,18 +44358,20 @@
             }
         },
         "com.amazonaws.ec2#Igmpv2SupportValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#Image": {
@@ -42036,6 +44421,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "IsPublic",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the image has public launch permissions. The value is <code>true</code> if\n\t\t\t\tthis image has public launch permissions or <code>false</code>\n\t\t\t\tif it has only implicit and explicit launch permissions.</p>",
                         "smithy.api#xmlName": "isPublic"
                     }
@@ -42124,6 +44511,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnaSupport",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specifies whether enhanced networking with ENA is enabled.</p>",
                         "smithy.api#xmlName": "enaSupport"
                     }
@@ -42334,54 +44723,74 @@
             }
         },
         "com.amazonaws.ec2#ImageAttributeName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "description",
-                        "name": "description"
-                    },
-                    {
-                        "value": "kernel",
-                        "name": "kernel"
-                    },
-                    {
-                        "value": "ramdisk",
-                        "name": "ramdisk"
-                    },
-                    {
-                        "value": "launchPermission",
-                        "name": "launchPermission"
-                    },
-                    {
-                        "value": "productCodes",
-                        "name": "productCodes"
-                    },
-                    {
-                        "value": "blockDeviceMapping",
-                        "name": "blockDeviceMapping"
-                    },
-                    {
-                        "value": "sriovNetSupport",
-                        "name": "sriovNetSupport"
-                    },
-                    {
-                        "value": "bootMode",
-                        "name": "bootMode"
-                    },
-                    {
-                        "value": "tpmSupport",
-                        "name": "tpmSupport"
-                    },
-                    {
-                        "value": "uefiData",
-                        "name": "uefiData"
-                    },
-                    {
-                        "value": "lastLaunchedTime",
-                        "name": "lastLaunchedTime"
+            "type": "enum",
+            "members": {
+                "description": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "description"
                     }
-                ]
+                },
+                "kernel": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "kernel"
+                    }
+                },
+                "ramdisk": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ramdisk"
+                    }
+                },
+                "launchPermission": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launchPermission"
+                    }
+                },
+                "productCodes": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "productCodes"
+                    }
+                },
+                "blockDeviceMapping": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "blockDeviceMapping"
+                    }
+                },
+                "sriovNetSupport": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "sriovNetSupport"
+                    }
+                },
+                "bootMode": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "bootMode"
+                    }
+                },
+                "tpmSupport": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "tpmSupport"
+                    }
+                },
+                "uefiData": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "uefiData"
+                    }
+                },
+                "lastLaunchedTime": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "lastLaunchedTime"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ImageDiskContainer": {
@@ -42525,57 +44934,73 @@
             }
         },
         "com.amazonaws.ec2#ImageState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "invalid",
-                        "name": "invalid"
-                    },
-                    {
-                        "value": "deregistered",
-                        "name": "deregistered"
-                    },
-                    {
-                        "value": "transient",
-                        "name": "transient"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
-                    },
-                    {
-                        "value": "error",
-                        "name": "error"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "invalid": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "invalid"
+                    }
+                },
+                "deregistered": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deregistered"
+                    }
+                },
+                "transient": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "transient"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "error": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "error"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ImageTypeValues": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "machine",
-                        "name": "machine"
-                    },
-                    {
-                        "value": "kernel",
-                        "name": "kernel"
-                    },
-                    {
-                        "value": "ramdisk",
-                        "name": "ramdisk"
+            "type": "enum",
+            "members": {
+                "machine": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "machine"
                     }
-                ]
+                },
+                "kernel": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "kernel"
+                    }
+                },
+                "ramdisk": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ramdisk"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ImportClientVpnClientCertificateRevocationList": {
@@ -42596,6 +45021,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint to which the client certificate revocation list applies.</p>",
                         "smithy.api#required": {}
                     }
@@ -42603,6 +45029,7 @@
                 "CertificateRevocationList": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The client certificate revocation list file. For more information, see <a href=\"https://docs.aws.amazon.com/vpn/latest/clientvpn-admin/cvpn-working-certificates.html#cvpn-working-certificates-generate\">Generate a Client Certificate Revocation List</a> in the\n\t\t\t\t<i>Client VPN Administrator Guide</i>.</p>",
                         "smithy.api#required": {}
                     }
@@ -42610,6 +45037,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -42622,6 +45051,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -42725,12 +45156,16 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "Encrypted": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specifies whether the destination AMI of the imported image should be encrypted. The default KMS key for EBS is used\n   unless you specify a non-default KMS key using <code>KmsKeyId</code>. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSEncryption.html\">Amazon EBS Encryption</a> in the\n    <i>Amazon Elastic Compute Cloud User Guide</i>.</p>"
                     }
                 },
@@ -42814,6 +45249,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the AMI is encrypted.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -42947,6 +45384,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the image is encrypted.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -43145,6 +45584,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Monitoring",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether monitoring is enabled.</p>",
                         "smithy.api#xmlName": "monitoring"
                     }
@@ -43209,6 +45650,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -43225,6 +45668,7 @@
                     "target": "com.amazonaws.ec2#PlatformValues",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Platform",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The instance operating system.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "platform"
@@ -43300,6 +45744,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "BytesConverted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of bytes converted so far.</p>",
                         "smithy.api#xmlName": "bytesConverted"
                     }
@@ -43377,6 +45823,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -43385,6 +45833,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "KeyName",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>A unique name for the key pair.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "keyName"
@@ -43394,6 +45843,7 @@
                     "target": "com.amazonaws.ec2#Blob",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PublicKeyMaterial",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The public key. For API calls, the text must be base64-encoded. For command line tools, base64 encoding is performed for you.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "publicKeyMaterial"
@@ -43487,12 +45937,16 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "Encrypted": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specifies whether the destination snapshot of the imported image should be encrypted. The default KMS key for EBS is\n   used unless you specify a non-default KMS key using <code>KmsKeyId</code>. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSEncryption.html\">Amazon EBS Encryption</a> in the\n    <i>Amazon Elastic Compute Cloud User Guide</i>.</p>"
                     }
                 },
@@ -43646,6 +46100,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AvailabilityZone",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Availability Zone for the resulting EBS volume.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "availabilityZone"
@@ -43663,6 +46118,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -43671,6 +46128,7 @@
                     "target": "com.amazonaws.ec2#DiskImageDetail",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Image",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The disk image.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "image"
@@ -43680,6 +46138,7 @@
                     "target": "com.amazonaws.ec2#VolumeDetail",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Volume",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The volume size.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "volume"
@@ -43715,6 +46174,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "BytesConverted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of bytes converted so far.</p>",
                         "smithy.api#xmlName": "bytesConverted"
                     }
@@ -43765,10 +46226,7 @@
             }
         },
         "com.amazonaws.ec2#InferenceDeviceCount": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#InferenceDeviceInfo": {
             "type": "structure",
@@ -43830,6 +46288,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AmiLaunchIndex",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The AMI launch index, which can be used to find this instance in the launch\n            group.</p>",
                         "smithy.api#xmlName": "amiLaunchIndex"
                     }
@@ -44014,6 +46474,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EbsOptimized",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the instance is optimized for Amazon EBS I/O. This optimization\n            provides dedicated throughput to Amazon EBS and an optimized configuration stack to\n            provide optimal I/O performance. This optimization isn't available with all instance\n            types. Additional usage charges apply when using an EBS Optimized instance.</p>",
                         "smithy.api#xmlName": "ebsOptimized"
                     }
@@ -44022,6 +46484,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnaSupport",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specifies whether enhanced networking with ENA is enabled.</p>",
                         "smithy.api#xmlName": "enaSupport"
                     }
@@ -44110,6 +46574,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SourceDestCheck",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether source/destination checking is enabled.</p>",
                         "smithy.api#xmlName": "sourceDestCheck"
                     }
@@ -44424,89 +46890,121 @@
             }
         },
         "com.amazonaws.ec2#InstanceAttributeName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "instanceType",
-                        "name": "instanceType"
-                    },
-                    {
-                        "value": "kernel",
-                        "name": "kernel"
-                    },
-                    {
-                        "value": "ramdisk",
-                        "name": "ramdisk"
-                    },
-                    {
-                        "value": "userData",
-                        "name": "userData"
-                    },
-                    {
-                        "value": "disableApiTermination",
-                        "name": "disableApiTermination"
-                    },
-                    {
-                        "value": "instanceInitiatedShutdownBehavior",
-                        "name": "instanceInitiatedShutdownBehavior"
-                    },
-                    {
-                        "value": "rootDeviceName",
-                        "name": "rootDeviceName"
-                    },
-                    {
-                        "value": "blockDeviceMapping",
-                        "name": "blockDeviceMapping"
-                    },
-                    {
-                        "value": "productCodes",
-                        "name": "productCodes"
-                    },
-                    {
-                        "value": "sourceDestCheck",
-                        "name": "sourceDestCheck"
-                    },
-                    {
-                        "value": "groupSet",
-                        "name": "groupSet"
-                    },
-                    {
-                        "value": "ebsOptimized",
-                        "name": "ebsOptimized"
-                    },
-                    {
-                        "value": "sriovNetSupport",
-                        "name": "sriovNetSupport"
-                    },
-                    {
-                        "value": "enaSupport",
-                        "name": "enaSupport"
-                    },
-                    {
-                        "value": "enclaveOptions",
-                        "name": "enclaveOptions"
-                    },
-                    {
-                        "value": "disableApiStop",
-                        "name": "disableApiStop"
+            "type": "enum",
+            "members": {
+                "instanceType": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instanceType"
                     }
-                ]
+                },
+                "kernel": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "kernel"
+                    }
+                },
+                "ramdisk": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ramdisk"
+                    }
+                },
+                "userData": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "userData"
+                    }
+                },
+                "disableApiTermination": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disableApiTermination"
+                    }
+                },
+                "instanceInitiatedShutdownBehavior": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instanceInitiatedShutdownBehavior"
+                    }
+                },
+                "rootDeviceName": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "rootDeviceName"
+                    }
+                },
+                "blockDeviceMapping": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "blockDeviceMapping"
+                    }
+                },
+                "productCodes": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "productCodes"
+                    }
+                },
+                "sourceDestCheck": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "sourceDestCheck"
+                    }
+                },
+                "groupSet": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "groupSet"
+                    }
+                },
+                "ebsOptimized": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ebsOptimized"
+                    }
+                },
+                "sriovNetSupport": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "sriovNetSupport"
+                    }
+                },
+                "enaSupport": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enaSupport"
+                    }
+                },
+                "enclaveOptions": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enclaveOptions"
+                    }
+                },
+                "disableApiStop": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disableApiStop"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceAutoRecoveryState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
-                    },
-                    {
-                        "value": "default",
-                        "name": "default"
+            "type": "enum",
+            "members": {
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
                     }
-                ]
+                },
+                "default": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "default"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceBlockDeviceMapping": {
@@ -44598,6 +47096,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AvailableCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of instances that can be launched onto the Dedicated Host based on the \n    \t\thost's available capacity.</p>",
                         "smithy.api#xmlName": "availableCapacity"
                     }
@@ -44614,6 +47114,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of instances that can be launched onto the Dedicated Host if there \n    \t\tare no instances running on it.</p>",
                         "smithy.api#xmlName": "totalCapacity"
                     }
@@ -44630,6 +47132,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of listed Reserved Instances in the state specified by the <code>state</code>.</p>",
                         "smithy.api#xmlName": "instanceCount"
                     }
@@ -44900,26 +47404,32 @@
             }
         },
         "com.amazonaws.ec2#InstanceEventWindowState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "creating",
-                        "name": "creating"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "creating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "creating"
                     }
-                ]
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceEventWindowStateChange": {
@@ -44961,6 +47471,8 @@
                     "target": "com.amazonaws.ec2#Hour",
                     "traits": {
                         "aws.protocols#ec2QueryName": "StartHour",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The hour when the time range begins.</p>",
                         "smithy.api#xmlName": "startHour"
                     }
@@ -44977,6 +47489,8 @@
                     "target": "com.amazonaws.ec2#Hour",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EndHour",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The hour when the time range ends.</p>",
                         "smithy.api#xmlName": "endHour"
                     }
@@ -45007,6 +47521,8 @@
                 "StartHour": {
                     "target": "com.amazonaws.ec2#Hour",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The hour when the time range begins.</p>"
                     }
                 },
@@ -45019,6 +47535,8 @@
                 "EndHour": {
                     "target": "com.amazonaws.ec2#Hour",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The hour when the time range ends.</p>"
                     }
                 }
@@ -45082,18 +47600,20 @@
             }
         },
         "com.amazonaws.ec2#InstanceGeneration": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "current",
-                        "name": "CURRENT"
-                    },
-                    {
-                        "value": "previous",
-                        "name": "PREVIOUS"
+            "type": "enum",
+            "members": {
+                "CURRENT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "current"
                     }
-                ]
+                },
+                "PREVIOUS": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "previous"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceGenerationSet": {
@@ -45106,18 +47626,20 @@
             }
         },
         "com.amazonaws.ec2#InstanceHealthStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "healthy",
-                        "name": "HEALTHY_STATUS"
-                    },
-                    {
-                        "value": "unhealthy",
-                        "name": "UNHEALTHY_STATUS"
+            "type": "enum",
+            "members": {
+                "HEALTHY_STATUS": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "healthy"
                     }
-                ]
+                },
+                "UNHEALTHY_STATUS": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unhealthy"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceId": {
@@ -45160,22 +47682,26 @@
             }
         },
         "com.amazonaws.ec2#InstanceInterruptionBehavior": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "hibernate",
-                        "name": "hibernate"
-                    },
-                    {
-                        "value": "stop",
-                        "name": "stop"
-                    },
-                    {
-                        "value": "terminate",
-                        "name": "terminate"
+            "type": "enum",
+            "members": {
+                "hibernate": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "hibernate"
                     }
-                ]
+                },
+                "stop": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "stop"
+                    }
+                },
+                "terminate": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "terminate"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceIpv4Prefix": {
@@ -45277,33 +47803,37 @@
             }
         },
         "com.amazonaws.ec2#InstanceLifecycle": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "spot",
-                        "name": "SPOT"
-                    },
-                    {
-                        "value": "on-demand",
-                        "name": "ON_DEMAND"
+            "type": "enum",
+            "members": {
+                "SPOT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "spot"
                     }
-                ]
+                },
+                "ON_DEMAND": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "on-demand"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceLifecycleType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "spot",
-                        "name": "spot"
-                    },
-                    {
-                        "value": "scheduled",
-                        "name": "scheduled"
+            "type": "enum",
+            "members": {
+                "spot": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "spot"
                     }
-                ]
+                },
+                "scheduled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "scheduled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceList": {
@@ -45366,33 +47896,37 @@
             }
         },
         "com.amazonaws.ec2#InstanceMatchCriteria": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "open",
-                        "name": "open"
-                    },
-                    {
-                        "value": "targeted",
-                        "name": "targeted"
+            "type": "enum",
+            "members": {
+                "open": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "open"
                     }
-                ]
+                },
+                "targeted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "targeted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceMetadataEndpointState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
-                    },
-                    {
-                        "value": "enabled",
-                        "name": "enabled"
+            "type": "enum",
+            "members": {
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
                     }
-                ]
+                },
+                "enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceMetadataOptionsRequest": {
@@ -45407,6 +47941,8 @@
                 "HttpPutResponseHopLimit": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The desired HTTP PUT response hop limit for instance metadata requests. The larger the\n            number, the further instance metadata requests can travel.</p>\n        <p>Default: 1</p>\n        <p>Possible values: Integers from 1 to 64</p>"
                     }
                 },
@@ -45456,6 +47992,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "HttpPutResponseHopLimit",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The desired HTTP PUT response hop limit for instance metadata requests. The larger the\n            number, the further instance metadata requests can travel.</p>\n        <p>Default: 1</p>\n        <p>Possible values: Integers from 1 to 64</p>",
                         "smithy.api#xmlName": "httpPutResponseHopLimit"
                     }
@@ -45490,48 +48028,54 @@
             }
         },
         "com.amazonaws.ec2#InstanceMetadataOptionsState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "applied",
-                        "name": "applied"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "applied": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "applied"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceMetadataProtocolState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
-                    },
-                    {
-                        "value": "enabled",
-                        "name": "enabled"
+            "type": "enum",
+            "members": {
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
                     }
-                ]
+                },
+                "enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceMetadataTagsState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
-                    },
-                    {
-                        "value": "enabled",
-                        "name": "enabled"
+            "type": "enum",
+            "members": {
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
                     }
-                ]
+                },
+                "enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceMonitoring": {
@@ -45662,6 +48206,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SourceDestCheck",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether source/destination checking is enabled.</p>",
                         "smithy.api#xmlName": "sourceDestCheck"
                     }
@@ -45790,6 +48336,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeleteOnTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the network interface is deleted when the instance is terminated.</p>",
                         "smithy.api#xmlName": "deleteOnTermination"
                     }
@@ -45798,6 +48346,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeviceIndex",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The index of the device on the instance for the network interface attachment.</p>",
                         "smithy.api#xmlName": "deviceIndex"
                     }
@@ -45814,6 +48364,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkCardIndex",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The index of the network card.</p>",
                         "smithy.api#xmlName": "networkCardIndex"
                     }
@@ -45839,6 +48391,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AssociatePublicIpAddress",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to assign a public IPv4 address to an instance you launch in a VPC. The\n            public IP address can only be assigned to a network interface for eth0, and can only be\n            assigned to a new network interface, not an existing one. You cannot specify more than one\n            network interface in the request. If launching into a default subnet, the default value is\n            <code>true</code>.</p>",
                         "smithy.api#xmlName": "associatePublicIpAddress"
                     }
@@ -45847,6 +48401,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeleteOnTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If set to <code>true</code>, the interface is deleted when the instance is terminated. You can\n            specify <code>true</code> only if creating a new network interface when launching an\n            instance.</p>",
                         "smithy.api#xmlName": "deleteOnTermination"
                     }
@@ -45863,6 +48419,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeviceIndex",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The position of the network interface in the attachment order. \n          A primary network interface has a device index of 0.</p> \n        <p>If you specify a network interface when launching an instance, \n          you must specify the device index.</p>",
                         "smithy.api#xmlName": "deviceIndex"
                     }
@@ -45878,6 +48436,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Ipv6AddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>A number of IPv6 addresses to assign to the network interface. Amazon EC2 chooses\n            the IPv6 addresses from the range of the subnet. You cannot specify this option and the\n            option to assign specific IPv6 addresses in the same request. You can specify this\n            option if you've specified a minimum number of instances to launch.</p>",
                         "smithy.api#xmlName": "ipv6AddressCount"
                     }
@@ -45918,6 +48478,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SecondaryPrivateIpAddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of secondary private IPv4 addresses. You can't specify this option and specify more than one private IP address using the private IP addresses option. You cannot specify this option if you're\n        \tlaunching more than one instance in a <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_RunInstances.html\">RunInstances</a> request.</p>",
                         "smithy.api#xmlName": "secondaryPrivateIpAddressCount"
                     }
@@ -45933,6 +48495,8 @@
                 "AssociateCarrierIpAddress": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to assign a carrier IP address to the network interface.</p>\n        <p>You can only assign a carrier IP address to a network interface that is in a subnet in\n            a Wavelength Zone. For more information about carrier IP addresses, see <a href=\"https://docs.aws.amazon.com/wavelength/latest/developerguide/how-wavelengths-work.html#provider-owned-ip\">Carrier IP address</a> in the <i>Amazon Web Services Wavelength Developer\n                Guide</i>.</p>"
                     }
                 },
@@ -45945,6 +48509,8 @@
                 "NetworkCardIndex": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The index of the network card. Some instance types support multiple network cards. \n            The primary network interface must be assigned to network card index 0. \n            The default is network card index 0.</p>\n        <p>If you are using <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_RequestSpotInstances.html\">RequestSpotInstances</a> to create Spot Instances, omit this parameter because\n            you can’t specify the network card index when using this API. To specify the network\n            card index, use <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_RunInstances.html\">RunInstances</a>.</p>"
                     }
                 },
@@ -45958,6 +48524,8 @@
                 "Ipv4PrefixCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv4 delegated prefixes to be automatically assigned to the network interface. \n            You cannot use this option if you use the <code>Ipv4Prefix</code> option.</p>"
                     }
                 },
@@ -45971,6 +48539,8 @@
                 "Ipv6PrefixCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv6 delegated prefixes to be automatically assigned to the network interface. \n            You cannot use this option if you use the <code>Ipv6Prefix</code> option.</p>"
                     }
                 }
@@ -46003,6 +48573,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Primary",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether this IPv4 address is the primary private IP address of the network interface.</p>",
                         "smithy.api#xmlName": "primary"
                     }
@@ -46092,6 +48664,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SpotMaxPricePercentageOverLowestPrice",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The price protection threshold for Spot Instances. This is the maximum you’ll pay for a Spot Instance,\n         expressed as a percentage above the least expensive current generation M, C, or R instance type with your specified\n         attributes. When Amazon EC2 selects instance types with your attributes, it excludes instance\n         types priced above your threshold.</p>\n         <p>The parameter accepts an integer, which Amazon EC2 interprets as a percentage.</p>\n         <p>To turn off price protection, specify a high value, such as <code>999999</code>.</p>\n         <p>This parameter is not supported for <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetSpotPlacementScores.html\">GetSpotPlacementScores</a> and <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetInstanceTypesFromInstanceRequirements.html\">GetInstanceTypesFromInstanceRequirements</a>.</p>\n         <note>\n            <p>If you set <code>TargetCapacityUnitType</code> to <code>vcpu</code> or\n               <code>memory-mib</code>, the price protection threshold is applied based on the\n            per-vCPU or per-memory price instead of the per-instance price.</p>\n         </note>\n         <p>Default: <code>100</code>\n         </p>",
                         "smithy.api#xmlName": "spotMaxPricePercentageOverLowestPrice"
                     }
@@ -46100,6 +48674,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "OnDemandMaxPricePercentageOverLowestPrice",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The price protection threshold for On-Demand Instances. This is the maximum you’ll pay for an On-Demand Instance,\n         expressed as a percentage above the least expensive current generation M, C, or R instance type with your specified\n         attributes. When Amazon EC2 selects instance types with your attributes, it excludes instance\n         types priced above your threshold.</p>\n         <p>The parameter accepts an integer, which Amazon EC2 interprets as a percentage.</p>\n         <p>To turn off price protection, specify a high value, such as <code>999999</code>.</p>\n         <p>This parameter is not supported for <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetSpotPlacementScores.html\">GetSpotPlacementScores</a> and <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetInstanceTypesFromInstanceRequirements.html\">GetInstanceTypesFromInstanceRequirements</a>.</p>\n         <note>\n            <p>If you set <code>TargetCapacityUnitType</code> to <code>vcpu</code> or\n         <code>memory-mib</code>, the price protection threshold is applied based on the\n         per-vCPU or per-memory price instead of the per-instance price.</p>\n         </note>\n         <p>Default: <code>20</code>\n         </p>",
                         "smithy.api#xmlName": "onDemandMaxPricePercentageOverLowestPrice"
                     }
@@ -46124,6 +48700,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RequireHibernateSupport",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether instance types must support hibernation for On-Demand\n         Instances.</p>\n         <p>This parameter is not supported for <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetSpotPlacementScores.html\">GetSpotPlacementScores</a>.</p>\n         <p>Default: <code>false</code>\n         </p>",
                         "smithy.api#xmlName": "requireHibernateSupport"
                     }
@@ -46219,6 +48797,7 @@
                 "VCpuCount": {
                     "target": "com.amazonaws.ec2#VCpuCountRangeRequest",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The minimum and maximum number of vCPUs.</p>",
                         "smithy.api#required": {}
                     }
@@ -46226,6 +48805,7 @@
                 "MemoryMiB": {
                     "target": "com.amazonaws.ec2#MemoryMiBRequest",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The minimum and maximum amount of memory, in MiB.</p>",
                         "smithy.api#required": {}
                     }
@@ -46260,12 +48840,16 @@
                 "SpotMaxPricePercentageOverLowestPrice": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The price protection threshold for Spot Instance. This is the maximum you’ll pay for an Spot Instance,\n         expressed as a percentage above the least expensive current generation M, C, or R instance type with your specified\n         attributes. When Amazon EC2 selects instance types with your attributes, it excludes instance\n         types priced above your threshold.</p>\n         <p>The parameter accepts an integer, which Amazon EC2 interprets as a percentage.</p>\n         <p>To turn off price protection, specify a high value, such as <code>999999</code>.</p>\n         <p>This parameter is not supported for <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetSpotPlacementScores.html\">GetSpotPlacementScores</a> and <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetInstanceTypesFromInstanceRequirements.html\">GetInstanceTypesFromInstanceRequirements</a>.</p>\n         <note>\n            <p>If you set <code>TargetCapacityUnitType</code> to <code>vcpu</code> or\n         <code>memory-mib</code>, the price protection threshold is applied based on the\n         per-vCPU or per-memory price instead of the per-instance price.</p>\n         </note>\n         <p>Default: <code>100</code>\n         </p>"
                     }
                 },
                 "OnDemandMaxPricePercentageOverLowestPrice": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The price protection threshold for On-Demand Instances. This is the maximum you’ll pay for an On-Demand Instance,\n         expressed as a percentage above the least expensive current generation M, C, or R instance type with your specified\n         attributes. When Amazon EC2 selects instance types with your attributes, it excludes instance\n         types priced above your threshold.</p>\n         <p>The parameter accepts an integer, which Amazon EC2 interprets as a percentage.</p>\n         <p>To turn off price protection, specify a high value, such as <code>999999</code>.</p>\n         <p>This parameter is not supported for <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetSpotPlacementScores.html\">GetSpotPlacementScores</a> and <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetInstanceTypesFromInstanceRequirements.html\">GetInstanceTypesFromInstanceRequirements</a>.</p>\n         <note>\n            <p>If you set <code>TargetCapacityUnitType</code> to <code>vcpu</code> or\n         <code>memory-mib</code>, the price protection threshold is applied based on the\n         per-vCPU or per-memory price instead of the per-instance price.</p>\n         </note>\n         <p>Default: <code>20</code>\n         </p>"
                     }
                 },
@@ -46284,6 +48868,8 @@
                 "RequireHibernateSupport": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether instance types must support hibernation for On-Demand Instances.</p>\n         <p>This parameter is not supported for <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetSpotPlacementScores.html\">GetSpotPlacementScores</a>.</p>\n         <p>Default: <code>false</code>\n         </p>"
                     }
                 },
@@ -46396,6 +48982,8 @@
                 "ExcludeBootVolume": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Excludes the root volume from being snapshotted.</p>"
                     }
                 },
@@ -46417,6 +49005,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Code",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The state of the instance as a 16-bit unsigned integer. </p>\n        <p>The high byte is all of the bits between 2^8 and (2^16)-1, which equals decimal values\n            between 256 and 65,535. These numerical values are used for internal purposes and should\n            be ignored.</p>\n        <p>The low byte is all of the bits between 2^0 and (2^8)-1, which equals decimal values\n            between 0 and 255. </p>\n        <p>The valid values for instance-state-code will all be in the range of the low byte and\n            they are:</p>\n        <ul>\n            <li>\n                <p>\n                    <code>0</code> : <code>pending</code>\n                </p>\n            </li>\n            <li>\n                <p>\n                    <code>16</code> : <code>running</code>\n                </p>\n            </li>\n            <li>\n                <p>\n                    <code>32</code> : <code>shutting-down</code>\n                </p>\n            </li>\n            <li>\n                <p>\n                    <code>48</code> : <code>terminated</code>\n                </p>\n            </li>\n            <li>\n                <p>\n                    <code>64</code> : <code>stopping</code>\n                </p>\n            </li>\n            <li>\n                <p>\n                    <code>80</code> : <code>stopped</code>\n                </p>\n            </li>\n         </ul>\n        <p>You can ignore the high byte value by zeroing out all of the bits above 2^8 or 256 in\n            decimal.</p>",
                         "smithy.api#xmlName": "code"
                     }
@@ -46476,34 +49066,44 @@
             }
         },
         "com.amazonaws.ec2#InstanceStateName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "running",
-                        "name": "running"
-                    },
-                    {
-                        "value": "shutting-down",
-                        "name": "shutting_down"
-                    },
-                    {
-                        "value": "terminated",
-                        "name": "terminated"
-                    },
-                    {
-                        "value": "stopping",
-                        "name": "stopping"
-                    },
-                    {
-                        "value": "stopped",
-                        "name": "stopped"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "running": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "running"
+                    }
+                },
+                "shutting_down": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "shutting-down"
+                    }
+                },
+                "terminated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "terminated"
+                    }
+                },
+                "stopping": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "stopping"
+                    }
+                },
+                "stopped": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "stopped"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceStatus": {
@@ -46710,25 +49310,24 @@
             }
         },
         "com.amazonaws.ec2#InstanceStorageEncryptionSupport": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "unsupported",
-                        "name": "unsupported"
-                    },
-                    {
-                        "value": "required",
-                        "name": "required"
+            "type": "enum",
+            "members": {
+                "unsupported": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unsupported"
                     }
-                ]
+                },
+                "required": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "required"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceStorageFlag": {
-            "type": "boolean",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "boolean"
         },
         "com.amazonaws.ec2#InstanceStorageInfo": {
             "type": "structure",
@@ -46794,6 +49393,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "IncludeAllTagsOfInstance",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates wheter all tag keys in the current Region are registered to appear in scheduled event notifications. \n      \t<code>true</code> indicates that all tag keys in the current Region are registered.</p>",
                         "smithy.api#xmlName": "includeAllTagsOfInstance"
                     }
@@ -46804,2297 +49405,3433 @@
             }
         },
         "com.amazonaws.ec2#InstanceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "a1.medium",
-                        "name": "a1_medium"
-                    },
-                    {
-                        "value": "a1.large",
-                        "name": "a1_large"
-                    },
-                    {
-                        "value": "a1.xlarge",
-                        "name": "a1_xlarge"
-                    },
-                    {
-                        "value": "a1.2xlarge",
-                        "name": "a1_2xlarge"
-                    },
-                    {
-                        "value": "a1.4xlarge",
-                        "name": "a1_4xlarge"
-                    },
-                    {
-                        "value": "a1.metal",
-                        "name": "a1_metal"
-                    },
-                    {
-                        "value": "c1.medium",
-                        "name": "c1_medium"
-                    },
-                    {
-                        "value": "c1.xlarge",
-                        "name": "c1_xlarge"
-                    },
-                    {
-                        "value": "c3.large",
-                        "name": "c3_large"
-                    },
-                    {
-                        "value": "c3.xlarge",
-                        "name": "c3_xlarge"
-                    },
-                    {
-                        "value": "c3.2xlarge",
-                        "name": "c3_2xlarge"
-                    },
-                    {
-                        "value": "c3.4xlarge",
-                        "name": "c3_4xlarge"
-                    },
-                    {
-                        "value": "c3.8xlarge",
-                        "name": "c3_8xlarge"
-                    },
-                    {
-                        "value": "c4.large",
-                        "name": "c4_large"
-                    },
-                    {
-                        "value": "c4.xlarge",
-                        "name": "c4_xlarge"
-                    },
-                    {
-                        "value": "c4.2xlarge",
-                        "name": "c4_2xlarge"
-                    },
-                    {
-                        "value": "c4.4xlarge",
-                        "name": "c4_4xlarge"
-                    },
-                    {
-                        "value": "c4.8xlarge",
-                        "name": "c4_8xlarge"
-                    },
-                    {
-                        "value": "c5.large",
-                        "name": "c5_large"
-                    },
-                    {
-                        "value": "c5.xlarge",
-                        "name": "c5_xlarge"
-                    },
-                    {
-                        "value": "c5.2xlarge",
-                        "name": "c5_2xlarge"
-                    },
-                    {
-                        "value": "c5.4xlarge",
-                        "name": "c5_4xlarge"
-                    },
-                    {
-                        "value": "c5.9xlarge",
-                        "name": "c5_9xlarge"
-                    },
-                    {
-                        "value": "c5.12xlarge",
-                        "name": "c5_12xlarge"
-                    },
-                    {
-                        "value": "c5.18xlarge",
-                        "name": "c5_18xlarge"
-                    },
-                    {
-                        "value": "c5.24xlarge",
-                        "name": "c5_24xlarge"
-                    },
-                    {
-                        "value": "c5.metal",
-                        "name": "c5_metal"
-                    },
-                    {
-                        "value": "c5a.large",
-                        "name": "c5a_large"
-                    },
-                    {
-                        "value": "c5a.xlarge",
-                        "name": "c5a_xlarge"
-                    },
-                    {
-                        "value": "c5a.2xlarge",
-                        "name": "c5a_2xlarge"
-                    },
-                    {
-                        "value": "c5a.4xlarge",
-                        "name": "c5a_4xlarge"
-                    },
-                    {
-                        "value": "c5a.8xlarge",
-                        "name": "c5a_8xlarge"
-                    },
-                    {
-                        "value": "c5a.12xlarge",
-                        "name": "c5a_12xlarge"
-                    },
-                    {
-                        "value": "c5a.16xlarge",
-                        "name": "c5a_16xlarge"
-                    },
-                    {
-                        "value": "c5a.24xlarge",
-                        "name": "c5a_24xlarge"
-                    },
-                    {
-                        "value": "c5ad.large",
-                        "name": "c5ad_large"
-                    },
-                    {
-                        "value": "c5ad.xlarge",
-                        "name": "c5ad_xlarge"
-                    },
-                    {
-                        "value": "c5ad.2xlarge",
-                        "name": "c5ad_2xlarge"
-                    },
-                    {
-                        "value": "c5ad.4xlarge",
-                        "name": "c5ad_4xlarge"
-                    },
-                    {
-                        "value": "c5ad.8xlarge",
-                        "name": "c5ad_8xlarge"
-                    },
-                    {
-                        "value": "c5ad.12xlarge",
-                        "name": "c5ad_12xlarge"
-                    },
-                    {
-                        "value": "c5ad.16xlarge",
-                        "name": "c5ad_16xlarge"
-                    },
-                    {
-                        "value": "c5ad.24xlarge",
-                        "name": "c5ad_24xlarge"
-                    },
-                    {
-                        "value": "c5d.large",
-                        "name": "c5d_large"
-                    },
-                    {
-                        "value": "c5d.xlarge",
-                        "name": "c5d_xlarge"
-                    },
-                    {
-                        "value": "c5d.2xlarge",
-                        "name": "c5d_2xlarge"
-                    },
-                    {
-                        "value": "c5d.4xlarge",
-                        "name": "c5d_4xlarge"
-                    },
-                    {
-                        "value": "c5d.9xlarge",
-                        "name": "c5d_9xlarge"
-                    },
-                    {
-                        "value": "c5d.12xlarge",
-                        "name": "c5d_12xlarge"
-                    },
-                    {
-                        "value": "c5d.18xlarge",
-                        "name": "c5d_18xlarge"
-                    },
-                    {
-                        "value": "c5d.24xlarge",
-                        "name": "c5d_24xlarge"
-                    },
-                    {
-                        "value": "c5d.metal",
-                        "name": "c5d_metal"
-                    },
-                    {
-                        "value": "c5n.large",
-                        "name": "c5n_large"
-                    },
-                    {
-                        "value": "c5n.xlarge",
-                        "name": "c5n_xlarge"
-                    },
-                    {
-                        "value": "c5n.2xlarge",
-                        "name": "c5n_2xlarge"
-                    },
-                    {
-                        "value": "c5n.4xlarge",
-                        "name": "c5n_4xlarge"
-                    },
-                    {
-                        "value": "c5n.9xlarge",
-                        "name": "c5n_9xlarge"
-                    },
-                    {
-                        "value": "c5n.18xlarge",
-                        "name": "c5n_18xlarge"
-                    },
-                    {
-                        "value": "c5n.metal",
-                        "name": "c5n_metal"
-                    },
-                    {
-                        "value": "c6g.medium",
-                        "name": "c6g_medium"
-                    },
-                    {
-                        "value": "c6g.large",
-                        "name": "c6g_large"
-                    },
-                    {
-                        "value": "c6g.xlarge",
-                        "name": "c6g_xlarge"
-                    },
-                    {
-                        "value": "c6g.2xlarge",
-                        "name": "c6g_2xlarge"
-                    },
-                    {
-                        "value": "c6g.4xlarge",
-                        "name": "c6g_4xlarge"
-                    },
-                    {
-                        "value": "c6g.8xlarge",
-                        "name": "c6g_8xlarge"
-                    },
-                    {
-                        "value": "c6g.12xlarge",
-                        "name": "c6g_12xlarge"
-                    },
-                    {
-                        "value": "c6g.16xlarge",
-                        "name": "c6g_16xlarge"
-                    },
-                    {
-                        "value": "c6g.metal",
-                        "name": "c6g_metal"
-                    },
-                    {
-                        "value": "c6gd.medium",
-                        "name": "c6gd_medium"
-                    },
-                    {
-                        "value": "c6gd.large",
-                        "name": "c6gd_large"
-                    },
-                    {
-                        "value": "c6gd.xlarge",
-                        "name": "c6gd_xlarge"
-                    },
-                    {
-                        "value": "c6gd.2xlarge",
-                        "name": "c6gd_2xlarge"
-                    },
-                    {
-                        "value": "c6gd.4xlarge",
-                        "name": "c6gd_4xlarge"
-                    },
-                    {
-                        "value": "c6gd.8xlarge",
-                        "name": "c6gd_8xlarge"
-                    },
-                    {
-                        "value": "c6gd.12xlarge",
-                        "name": "c6gd_12xlarge"
-                    },
-                    {
-                        "value": "c6gd.16xlarge",
-                        "name": "c6gd_16xlarge"
-                    },
-                    {
-                        "value": "c6gd.metal",
-                        "name": "c6gd_metal"
-                    },
-                    {
-                        "value": "c6gn.medium",
-                        "name": "c6gn_medium"
-                    },
-                    {
-                        "value": "c6gn.large",
-                        "name": "c6gn_large"
-                    },
-                    {
-                        "value": "c6gn.xlarge",
-                        "name": "c6gn_xlarge"
-                    },
-                    {
-                        "value": "c6gn.2xlarge",
-                        "name": "c6gn_2xlarge"
-                    },
-                    {
-                        "value": "c6gn.4xlarge",
-                        "name": "c6gn_4xlarge"
-                    },
-                    {
-                        "value": "c6gn.8xlarge",
-                        "name": "c6gn_8xlarge"
-                    },
-                    {
-                        "value": "c6gn.12xlarge",
-                        "name": "c6gn_12xlarge"
-                    },
-                    {
-                        "value": "c6gn.16xlarge",
-                        "name": "c6gn_16xlarge"
-                    },
-                    {
-                        "value": "c6i.large",
-                        "name": "c6i_large"
-                    },
-                    {
-                        "value": "c6i.xlarge",
-                        "name": "c6i_xlarge"
-                    },
-                    {
-                        "value": "c6i.2xlarge",
-                        "name": "c6i_2xlarge"
-                    },
-                    {
-                        "value": "c6i.4xlarge",
-                        "name": "c6i_4xlarge"
-                    },
-                    {
-                        "value": "c6i.8xlarge",
-                        "name": "c6i_8xlarge"
-                    },
-                    {
-                        "value": "c6i.12xlarge",
-                        "name": "c6i_12xlarge"
-                    },
-                    {
-                        "value": "c6i.16xlarge",
-                        "name": "c6i_16xlarge"
-                    },
-                    {
-                        "value": "c6i.24xlarge",
-                        "name": "c6i_24xlarge"
-                    },
-                    {
-                        "value": "c6i.32xlarge",
-                        "name": "c6i_32xlarge"
-                    },
-                    {
-                        "value": "c6i.metal",
-                        "name": "c6i_metal"
-                    },
-                    {
-                        "value": "cc1.4xlarge",
-                        "name": "cc1_4xlarge"
-                    },
-                    {
-                        "value": "cc2.8xlarge",
-                        "name": "cc2_8xlarge"
-                    },
-                    {
-                        "value": "cg1.4xlarge",
-                        "name": "cg1_4xlarge"
-                    },
-                    {
-                        "value": "cr1.8xlarge",
-                        "name": "cr1_8xlarge"
-                    },
-                    {
-                        "value": "d2.xlarge",
-                        "name": "d2_xlarge"
-                    },
-                    {
-                        "value": "d2.2xlarge",
-                        "name": "d2_2xlarge"
-                    },
-                    {
-                        "value": "d2.4xlarge",
-                        "name": "d2_4xlarge"
-                    },
-                    {
-                        "value": "d2.8xlarge",
-                        "name": "d2_8xlarge"
-                    },
-                    {
-                        "value": "d3.xlarge",
-                        "name": "d3_xlarge"
-                    },
-                    {
-                        "value": "d3.2xlarge",
-                        "name": "d3_2xlarge"
-                    },
-                    {
-                        "value": "d3.4xlarge",
-                        "name": "d3_4xlarge"
-                    },
-                    {
-                        "value": "d3.8xlarge",
-                        "name": "d3_8xlarge"
-                    },
-                    {
-                        "value": "d3en.xlarge",
-                        "name": "d3en_xlarge"
-                    },
-                    {
-                        "value": "d3en.2xlarge",
-                        "name": "d3en_2xlarge"
-                    },
-                    {
-                        "value": "d3en.4xlarge",
-                        "name": "d3en_4xlarge"
-                    },
-                    {
-                        "value": "d3en.6xlarge",
-                        "name": "d3en_6xlarge"
-                    },
-                    {
-                        "value": "d3en.8xlarge",
-                        "name": "d3en_8xlarge"
-                    },
-                    {
-                        "value": "d3en.12xlarge",
-                        "name": "d3en_12xlarge"
-                    },
-                    {
-                        "value": "dl1.24xlarge",
-                        "name": "dl1_24xlarge"
-                    },
-                    {
-                        "value": "f1.2xlarge",
-                        "name": "f1_2xlarge"
-                    },
-                    {
-                        "value": "f1.4xlarge",
-                        "name": "f1_4xlarge"
-                    },
-                    {
-                        "value": "f1.16xlarge",
-                        "name": "f1_16xlarge"
-                    },
-                    {
-                        "value": "g2.2xlarge",
-                        "name": "g2_2xlarge"
-                    },
-                    {
-                        "value": "g2.8xlarge",
-                        "name": "g2_8xlarge"
-                    },
-                    {
-                        "value": "g3.4xlarge",
-                        "name": "g3_4xlarge"
-                    },
-                    {
-                        "value": "g3.8xlarge",
-                        "name": "g3_8xlarge"
-                    },
-                    {
-                        "value": "g3.16xlarge",
-                        "name": "g3_16xlarge"
-                    },
-                    {
-                        "value": "g3s.xlarge",
-                        "name": "g3s_xlarge"
-                    },
-                    {
-                        "value": "g4ad.xlarge",
-                        "name": "g4ad_xlarge"
-                    },
-                    {
-                        "value": "g4ad.2xlarge",
-                        "name": "g4ad_2xlarge"
-                    },
-                    {
-                        "value": "g4ad.4xlarge",
-                        "name": "g4ad_4xlarge"
-                    },
-                    {
-                        "value": "g4ad.8xlarge",
-                        "name": "g4ad_8xlarge"
-                    },
-                    {
-                        "value": "g4ad.16xlarge",
-                        "name": "g4ad_16xlarge"
-                    },
-                    {
-                        "value": "g4dn.xlarge",
-                        "name": "g4dn_xlarge"
-                    },
-                    {
-                        "value": "g4dn.2xlarge",
-                        "name": "g4dn_2xlarge"
-                    },
-                    {
-                        "value": "g4dn.4xlarge",
-                        "name": "g4dn_4xlarge"
-                    },
-                    {
-                        "value": "g4dn.8xlarge",
-                        "name": "g4dn_8xlarge"
-                    },
-                    {
-                        "value": "g4dn.12xlarge",
-                        "name": "g4dn_12xlarge"
-                    },
-                    {
-                        "value": "g4dn.16xlarge",
-                        "name": "g4dn_16xlarge"
-                    },
-                    {
-                        "value": "g4dn.metal",
-                        "name": "g4dn_metal"
-                    },
-                    {
-                        "value": "g5.xlarge",
-                        "name": "g5_xlarge"
-                    },
-                    {
-                        "value": "g5.2xlarge",
-                        "name": "g5_2xlarge"
-                    },
-                    {
-                        "value": "g5.4xlarge",
-                        "name": "g5_4xlarge"
-                    },
-                    {
-                        "value": "g5.8xlarge",
-                        "name": "g5_8xlarge"
-                    },
-                    {
-                        "value": "g5.12xlarge",
-                        "name": "g5_12xlarge"
-                    },
-                    {
-                        "value": "g5.16xlarge",
-                        "name": "g5_16xlarge"
-                    },
-                    {
-                        "value": "g5.24xlarge",
-                        "name": "g5_24xlarge"
-                    },
-                    {
-                        "value": "g5.48xlarge",
-                        "name": "g5_48xlarge"
-                    },
-                    {
-                        "value": "g5g.xlarge",
-                        "name": "g5g_xlarge"
-                    },
-                    {
-                        "value": "g5g.2xlarge",
-                        "name": "g5g_2xlarge"
-                    },
-                    {
-                        "value": "g5g.4xlarge",
-                        "name": "g5g_4xlarge"
-                    },
-                    {
-                        "value": "g5g.8xlarge",
-                        "name": "g5g_8xlarge"
-                    },
-                    {
-                        "value": "g5g.16xlarge",
-                        "name": "g5g_16xlarge"
-                    },
-                    {
-                        "value": "g5g.metal",
-                        "name": "g5g_metal"
-                    },
-                    {
-                        "value": "hi1.4xlarge",
-                        "name": "hi1_4xlarge"
-                    },
-                    {
-                        "value": "hpc6a.48xlarge",
-                        "name": "hpc6a_48xlarge"
-                    },
-                    {
-                        "value": "hs1.8xlarge",
-                        "name": "hs1_8xlarge"
-                    },
-                    {
-                        "value": "h1.2xlarge",
-                        "name": "h1_2xlarge"
-                    },
-                    {
-                        "value": "h1.4xlarge",
-                        "name": "h1_4xlarge"
-                    },
-                    {
-                        "value": "h1.8xlarge",
-                        "name": "h1_8xlarge"
-                    },
-                    {
-                        "value": "h1.16xlarge",
-                        "name": "h1_16xlarge"
-                    },
-                    {
-                        "value": "i2.xlarge",
-                        "name": "i2_xlarge"
-                    },
-                    {
-                        "value": "i2.2xlarge",
-                        "name": "i2_2xlarge"
-                    },
-                    {
-                        "value": "i2.4xlarge",
-                        "name": "i2_4xlarge"
-                    },
-                    {
-                        "value": "i2.8xlarge",
-                        "name": "i2_8xlarge"
-                    },
-                    {
-                        "value": "i3.large",
-                        "name": "i3_large"
-                    },
-                    {
-                        "value": "i3.xlarge",
-                        "name": "i3_xlarge"
-                    },
-                    {
-                        "value": "i3.2xlarge",
-                        "name": "i3_2xlarge"
-                    },
-                    {
-                        "value": "i3.4xlarge",
-                        "name": "i3_4xlarge"
-                    },
-                    {
-                        "value": "i3.8xlarge",
-                        "name": "i3_8xlarge"
-                    },
-                    {
-                        "value": "i3.16xlarge",
-                        "name": "i3_16xlarge"
-                    },
-                    {
-                        "value": "i3.metal",
-                        "name": "i3_metal"
-                    },
-                    {
-                        "value": "i3en.large",
-                        "name": "i3en_large"
-                    },
-                    {
-                        "value": "i3en.xlarge",
-                        "name": "i3en_xlarge"
-                    },
-                    {
-                        "value": "i3en.2xlarge",
-                        "name": "i3en_2xlarge"
-                    },
-                    {
-                        "value": "i3en.3xlarge",
-                        "name": "i3en_3xlarge"
-                    },
-                    {
-                        "value": "i3en.6xlarge",
-                        "name": "i3en_6xlarge"
-                    },
-                    {
-                        "value": "i3en.12xlarge",
-                        "name": "i3en_12xlarge"
-                    },
-                    {
-                        "value": "i3en.24xlarge",
-                        "name": "i3en_24xlarge"
-                    },
-                    {
-                        "value": "i3en.metal",
-                        "name": "i3en_metal"
-                    },
-                    {
-                        "value": "im4gn.large",
-                        "name": "im4gn_large"
-                    },
-                    {
-                        "value": "im4gn.xlarge",
-                        "name": "im4gn_xlarge"
-                    },
-                    {
-                        "value": "im4gn.2xlarge",
-                        "name": "im4gn_2xlarge"
-                    },
-                    {
-                        "value": "im4gn.4xlarge",
-                        "name": "im4gn_4xlarge"
-                    },
-                    {
-                        "value": "im4gn.8xlarge",
-                        "name": "im4gn_8xlarge"
-                    },
-                    {
-                        "value": "im4gn.16xlarge",
-                        "name": "im4gn_16xlarge"
-                    },
-                    {
-                        "value": "inf1.xlarge",
-                        "name": "inf1_xlarge"
-                    },
-                    {
-                        "value": "inf1.2xlarge",
-                        "name": "inf1_2xlarge"
-                    },
-                    {
-                        "value": "inf1.6xlarge",
-                        "name": "inf1_6xlarge"
-                    },
-                    {
-                        "value": "inf1.24xlarge",
-                        "name": "inf1_24xlarge"
-                    },
-                    {
-                        "value": "is4gen.medium",
-                        "name": "is4gen_medium"
-                    },
-                    {
-                        "value": "is4gen.large",
-                        "name": "is4gen_large"
-                    },
-                    {
-                        "value": "is4gen.xlarge",
-                        "name": "is4gen_xlarge"
-                    },
-                    {
-                        "value": "is4gen.2xlarge",
-                        "name": "is4gen_2xlarge"
-                    },
-                    {
-                        "value": "is4gen.4xlarge",
-                        "name": "is4gen_4xlarge"
-                    },
-                    {
-                        "value": "is4gen.8xlarge",
-                        "name": "is4gen_8xlarge"
-                    },
-                    {
-                        "value": "m1.small",
-                        "name": "m1_small"
-                    },
-                    {
-                        "value": "m1.medium",
-                        "name": "m1_medium"
-                    },
-                    {
-                        "value": "m1.large",
-                        "name": "m1_large"
-                    },
-                    {
-                        "value": "m1.xlarge",
-                        "name": "m1_xlarge"
-                    },
-                    {
-                        "value": "m2.xlarge",
-                        "name": "m2_xlarge"
-                    },
-                    {
-                        "value": "m2.2xlarge",
-                        "name": "m2_2xlarge"
-                    },
-                    {
-                        "value": "m2.4xlarge",
-                        "name": "m2_4xlarge"
-                    },
-                    {
-                        "value": "m3.medium",
-                        "name": "m3_medium"
-                    },
-                    {
-                        "value": "m3.large",
-                        "name": "m3_large"
-                    },
-                    {
-                        "value": "m3.xlarge",
-                        "name": "m3_xlarge"
-                    },
-                    {
-                        "value": "m3.2xlarge",
-                        "name": "m3_2xlarge"
-                    },
-                    {
-                        "value": "m4.large",
-                        "name": "m4_large"
-                    },
-                    {
-                        "value": "m4.xlarge",
-                        "name": "m4_xlarge"
-                    },
-                    {
-                        "value": "m4.2xlarge",
-                        "name": "m4_2xlarge"
-                    },
-                    {
-                        "value": "m4.4xlarge",
-                        "name": "m4_4xlarge"
-                    },
-                    {
-                        "value": "m4.10xlarge",
-                        "name": "m4_10xlarge"
-                    },
-                    {
-                        "value": "m4.16xlarge",
-                        "name": "m4_16xlarge"
-                    },
-                    {
-                        "value": "m5.large",
-                        "name": "m5_large"
-                    },
-                    {
-                        "value": "m5.xlarge",
-                        "name": "m5_xlarge"
-                    },
-                    {
-                        "value": "m5.2xlarge",
-                        "name": "m5_2xlarge"
-                    },
-                    {
-                        "value": "m5.4xlarge",
-                        "name": "m5_4xlarge"
-                    },
-                    {
-                        "value": "m5.8xlarge",
-                        "name": "m5_8xlarge"
-                    },
-                    {
-                        "value": "m5.12xlarge",
-                        "name": "m5_12xlarge"
-                    },
-                    {
-                        "value": "m5.16xlarge",
-                        "name": "m5_16xlarge"
-                    },
-                    {
-                        "value": "m5.24xlarge",
-                        "name": "m5_24xlarge"
-                    },
-                    {
-                        "value": "m5.metal",
-                        "name": "m5_metal"
-                    },
-                    {
-                        "value": "m5a.large",
-                        "name": "m5a_large"
-                    },
-                    {
-                        "value": "m5a.xlarge",
-                        "name": "m5a_xlarge"
-                    },
-                    {
-                        "value": "m5a.2xlarge",
-                        "name": "m5a_2xlarge"
-                    },
-                    {
-                        "value": "m5a.4xlarge",
-                        "name": "m5a_4xlarge"
-                    },
-                    {
-                        "value": "m5a.8xlarge",
-                        "name": "m5a_8xlarge"
-                    },
-                    {
-                        "value": "m5a.12xlarge",
-                        "name": "m5a_12xlarge"
-                    },
-                    {
-                        "value": "m5a.16xlarge",
-                        "name": "m5a_16xlarge"
-                    },
-                    {
-                        "value": "m5a.24xlarge",
-                        "name": "m5a_24xlarge"
-                    },
-                    {
-                        "value": "m5ad.large",
-                        "name": "m5ad_large"
-                    },
-                    {
-                        "value": "m5ad.xlarge",
-                        "name": "m5ad_xlarge"
-                    },
-                    {
-                        "value": "m5ad.2xlarge",
-                        "name": "m5ad_2xlarge"
-                    },
-                    {
-                        "value": "m5ad.4xlarge",
-                        "name": "m5ad_4xlarge"
-                    },
-                    {
-                        "value": "m5ad.8xlarge",
-                        "name": "m5ad_8xlarge"
-                    },
-                    {
-                        "value": "m5ad.12xlarge",
-                        "name": "m5ad_12xlarge"
-                    },
-                    {
-                        "value": "m5ad.16xlarge",
-                        "name": "m5ad_16xlarge"
-                    },
-                    {
-                        "value": "m5ad.24xlarge",
-                        "name": "m5ad_24xlarge"
-                    },
-                    {
-                        "value": "m5d.large",
-                        "name": "m5d_large"
-                    },
-                    {
-                        "value": "m5d.xlarge",
-                        "name": "m5d_xlarge"
-                    },
-                    {
-                        "value": "m5d.2xlarge",
-                        "name": "m5d_2xlarge"
-                    },
-                    {
-                        "value": "m5d.4xlarge",
-                        "name": "m5d_4xlarge"
-                    },
-                    {
-                        "value": "m5d.8xlarge",
-                        "name": "m5d_8xlarge"
-                    },
-                    {
-                        "value": "m5d.12xlarge",
-                        "name": "m5d_12xlarge"
-                    },
-                    {
-                        "value": "m5d.16xlarge",
-                        "name": "m5d_16xlarge"
-                    },
-                    {
-                        "value": "m5d.24xlarge",
-                        "name": "m5d_24xlarge"
-                    },
-                    {
-                        "value": "m5d.metal",
-                        "name": "m5d_metal"
-                    },
-                    {
-                        "value": "m5dn.large",
-                        "name": "m5dn_large"
-                    },
-                    {
-                        "value": "m5dn.xlarge",
-                        "name": "m5dn_xlarge"
-                    },
-                    {
-                        "value": "m5dn.2xlarge",
-                        "name": "m5dn_2xlarge"
-                    },
-                    {
-                        "value": "m5dn.4xlarge",
-                        "name": "m5dn_4xlarge"
-                    },
-                    {
-                        "value": "m5dn.8xlarge",
-                        "name": "m5dn_8xlarge"
-                    },
-                    {
-                        "value": "m5dn.12xlarge",
-                        "name": "m5dn_12xlarge"
-                    },
-                    {
-                        "value": "m5dn.16xlarge",
-                        "name": "m5dn_16xlarge"
-                    },
-                    {
-                        "value": "m5dn.24xlarge",
-                        "name": "m5dn_24xlarge"
-                    },
-                    {
-                        "value": "m5dn.metal",
-                        "name": "m5dn_metal"
-                    },
-                    {
-                        "value": "m5n.large",
-                        "name": "m5n_large"
-                    },
-                    {
-                        "value": "m5n.xlarge",
-                        "name": "m5n_xlarge"
-                    },
-                    {
-                        "value": "m5n.2xlarge",
-                        "name": "m5n_2xlarge"
-                    },
-                    {
-                        "value": "m5n.4xlarge",
-                        "name": "m5n_4xlarge"
-                    },
-                    {
-                        "value": "m5n.8xlarge",
-                        "name": "m5n_8xlarge"
-                    },
-                    {
-                        "value": "m5n.12xlarge",
-                        "name": "m5n_12xlarge"
-                    },
-                    {
-                        "value": "m5n.16xlarge",
-                        "name": "m5n_16xlarge"
-                    },
-                    {
-                        "value": "m5n.24xlarge",
-                        "name": "m5n_24xlarge"
-                    },
-                    {
-                        "value": "m5n.metal",
-                        "name": "m5n_metal"
-                    },
-                    {
-                        "value": "m5zn.large",
-                        "name": "m5zn_large"
-                    },
-                    {
-                        "value": "m5zn.xlarge",
-                        "name": "m5zn_xlarge"
-                    },
-                    {
-                        "value": "m5zn.2xlarge",
-                        "name": "m5zn_2xlarge"
-                    },
-                    {
-                        "value": "m5zn.3xlarge",
-                        "name": "m5zn_3xlarge"
-                    },
-                    {
-                        "value": "m5zn.6xlarge",
-                        "name": "m5zn_6xlarge"
-                    },
-                    {
-                        "value": "m5zn.12xlarge",
-                        "name": "m5zn_12xlarge"
-                    },
-                    {
-                        "value": "m5zn.metal",
-                        "name": "m5zn_metal"
-                    },
-                    {
-                        "value": "m6a.large",
-                        "name": "m6a_large"
-                    },
-                    {
-                        "value": "m6a.xlarge",
-                        "name": "m6a_xlarge"
-                    },
-                    {
-                        "value": "m6a.2xlarge",
-                        "name": "m6a_2xlarge"
-                    },
-                    {
-                        "value": "m6a.4xlarge",
-                        "name": "m6a_4xlarge"
-                    },
-                    {
-                        "value": "m6a.8xlarge",
-                        "name": "m6a_8xlarge"
-                    },
-                    {
-                        "value": "m6a.12xlarge",
-                        "name": "m6a_12xlarge"
-                    },
-                    {
-                        "value": "m6a.16xlarge",
-                        "name": "m6a_16xlarge"
-                    },
-                    {
-                        "value": "m6a.24xlarge",
-                        "name": "m6a_24xlarge"
-                    },
-                    {
-                        "value": "m6a.32xlarge",
-                        "name": "m6a_32xlarge"
-                    },
-                    {
-                        "value": "m6a.48xlarge",
-                        "name": "m6a_48xlarge"
-                    },
-                    {
-                        "value": "m6g.metal",
-                        "name": "m6g_metal"
-                    },
-                    {
-                        "value": "m6g.medium",
-                        "name": "m6g_medium"
-                    },
-                    {
-                        "value": "m6g.large",
-                        "name": "m6g_large"
-                    },
-                    {
-                        "value": "m6g.xlarge",
-                        "name": "m6g_xlarge"
-                    },
-                    {
-                        "value": "m6g.2xlarge",
-                        "name": "m6g_2xlarge"
-                    },
-                    {
-                        "value": "m6g.4xlarge",
-                        "name": "m6g_4xlarge"
-                    },
-                    {
-                        "value": "m6g.8xlarge",
-                        "name": "m6g_8xlarge"
-                    },
-                    {
-                        "value": "m6g.12xlarge",
-                        "name": "m6g_12xlarge"
-                    },
-                    {
-                        "value": "m6g.16xlarge",
-                        "name": "m6g_16xlarge"
-                    },
-                    {
-                        "value": "m6gd.metal",
-                        "name": "m6gd_metal"
-                    },
-                    {
-                        "value": "m6gd.medium",
-                        "name": "m6gd_medium"
-                    },
-                    {
-                        "value": "m6gd.large",
-                        "name": "m6gd_large"
-                    },
-                    {
-                        "value": "m6gd.xlarge",
-                        "name": "m6gd_xlarge"
-                    },
-                    {
-                        "value": "m6gd.2xlarge",
-                        "name": "m6gd_2xlarge"
-                    },
-                    {
-                        "value": "m6gd.4xlarge",
-                        "name": "m6gd_4xlarge"
-                    },
-                    {
-                        "value": "m6gd.8xlarge",
-                        "name": "m6gd_8xlarge"
-                    },
-                    {
-                        "value": "m6gd.12xlarge",
-                        "name": "m6gd_12xlarge"
-                    },
-                    {
-                        "value": "m6gd.16xlarge",
-                        "name": "m6gd_16xlarge"
-                    },
-                    {
-                        "value": "m6i.large",
-                        "name": "m6i_large"
-                    },
-                    {
-                        "value": "m6i.xlarge",
-                        "name": "m6i_xlarge"
-                    },
-                    {
-                        "value": "m6i.2xlarge",
-                        "name": "m6i_2xlarge"
-                    },
-                    {
-                        "value": "m6i.4xlarge",
-                        "name": "m6i_4xlarge"
-                    },
-                    {
-                        "value": "m6i.8xlarge",
-                        "name": "m6i_8xlarge"
-                    },
-                    {
-                        "value": "m6i.12xlarge",
-                        "name": "m6i_12xlarge"
-                    },
-                    {
-                        "value": "m6i.16xlarge",
-                        "name": "m6i_16xlarge"
-                    },
-                    {
-                        "value": "m6i.24xlarge",
-                        "name": "m6i_24xlarge"
-                    },
-                    {
-                        "value": "m6i.32xlarge",
-                        "name": "m6i_32xlarge"
-                    },
-                    {
-                        "value": "m6i.metal",
-                        "name": "m6i_metal"
-                    },
-                    {
-                        "value": "mac1.metal",
-                        "name": "mac1_metal"
-                    },
-                    {
-                        "value": "p2.xlarge",
-                        "name": "p2_xlarge"
-                    },
-                    {
-                        "value": "p2.8xlarge",
-                        "name": "p2_8xlarge"
-                    },
-                    {
-                        "value": "p2.16xlarge",
-                        "name": "p2_16xlarge"
-                    },
-                    {
-                        "value": "p3.2xlarge",
-                        "name": "p3_2xlarge"
-                    },
-                    {
-                        "value": "p3.8xlarge",
-                        "name": "p3_8xlarge"
-                    },
-                    {
-                        "value": "p3.16xlarge",
-                        "name": "p3_16xlarge"
-                    },
-                    {
-                        "value": "p3dn.24xlarge",
-                        "name": "p3dn_24xlarge"
-                    },
-                    {
-                        "value": "p4d.24xlarge",
-                        "name": "p4d_24xlarge"
-                    },
-                    {
-                        "value": "r3.large",
-                        "name": "r3_large"
-                    },
-                    {
-                        "value": "r3.xlarge",
-                        "name": "r3_xlarge"
-                    },
-                    {
-                        "value": "r3.2xlarge",
-                        "name": "r3_2xlarge"
-                    },
-                    {
-                        "value": "r3.4xlarge",
-                        "name": "r3_4xlarge"
-                    },
-                    {
-                        "value": "r3.8xlarge",
-                        "name": "r3_8xlarge"
-                    },
-                    {
-                        "value": "r4.large",
-                        "name": "r4_large"
-                    },
-                    {
-                        "value": "r4.xlarge",
-                        "name": "r4_xlarge"
-                    },
-                    {
-                        "value": "r4.2xlarge",
-                        "name": "r4_2xlarge"
-                    },
-                    {
-                        "value": "r4.4xlarge",
-                        "name": "r4_4xlarge"
-                    },
-                    {
-                        "value": "r4.8xlarge",
-                        "name": "r4_8xlarge"
-                    },
-                    {
-                        "value": "r4.16xlarge",
-                        "name": "r4_16xlarge"
-                    },
-                    {
-                        "value": "r5.large",
-                        "name": "r5_large"
-                    },
-                    {
-                        "value": "r5.xlarge",
-                        "name": "r5_xlarge"
-                    },
-                    {
-                        "value": "r5.2xlarge",
-                        "name": "r5_2xlarge"
-                    },
-                    {
-                        "value": "r5.4xlarge",
-                        "name": "r5_4xlarge"
-                    },
-                    {
-                        "value": "r5.8xlarge",
-                        "name": "r5_8xlarge"
-                    },
-                    {
-                        "value": "r5.12xlarge",
-                        "name": "r5_12xlarge"
-                    },
-                    {
-                        "value": "r5.16xlarge",
-                        "name": "r5_16xlarge"
-                    },
-                    {
-                        "value": "r5.24xlarge",
-                        "name": "r5_24xlarge"
-                    },
-                    {
-                        "value": "r5.metal",
-                        "name": "r5_metal"
-                    },
-                    {
-                        "value": "r5a.large",
-                        "name": "r5a_large"
-                    },
-                    {
-                        "value": "r5a.xlarge",
-                        "name": "r5a_xlarge"
-                    },
-                    {
-                        "value": "r5a.2xlarge",
-                        "name": "r5a_2xlarge"
-                    },
-                    {
-                        "value": "r5a.4xlarge",
-                        "name": "r5a_4xlarge"
-                    },
-                    {
-                        "value": "r5a.8xlarge",
-                        "name": "r5a_8xlarge"
-                    },
-                    {
-                        "value": "r5a.12xlarge",
-                        "name": "r5a_12xlarge"
-                    },
-                    {
-                        "value": "r5a.16xlarge",
-                        "name": "r5a_16xlarge"
-                    },
-                    {
-                        "value": "r5a.24xlarge",
-                        "name": "r5a_24xlarge"
-                    },
-                    {
-                        "value": "r5ad.large",
-                        "name": "r5ad_large"
-                    },
-                    {
-                        "value": "r5ad.xlarge",
-                        "name": "r5ad_xlarge"
-                    },
-                    {
-                        "value": "r5ad.2xlarge",
-                        "name": "r5ad_2xlarge"
-                    },
-                    {
-                        "value": "r5ad.4xlarge",
-                        "name": "r5ad_4xlarge"
-                    },
-                    {
-                        "value": "r5ad.8xlarge",
-                        "name": "r5ad_8xlarge"
-                    },
-                    {
-                        "value": "r5ad.12xlarge",
-                        "name": "r5ad_12xlarge"
-                    },
-                    {
-                        "value": "r5ad.16xlarge",
-                        "name": "r5ad_16xlarge"
-                    },
-                    {
-                        "value": "r5ad.24xlarge",
-                        "name": "r5ad_24xlarge"
-                    },
-                    {
-                        "value": "r5b.large",
-                        "name": "r5b_large"
-                    },
-                    {
-                        "value": "r5b.xlarge",
-                        "name": "r5b_xlarge"
-                    },
-                    {
-                        "value": "r5b.2xlarge",
-                        "name": "r5b_2xlarge"
-                    },
-                    {
-                        "value": "r5b.4xlarge",
-                        "name": "r5b_4xlarge"
-                    },
-                    {
-                        "value": "r5b.8xlarge",
-                        "name": "r5b_8xlarge"
-                    },
-                    {
-                        "value": "r5b.12xlarge",
-                        "name": "r5b_12xlarge"
-                    },
-                    {
-                        "value": "r5b.16xlarge",
-                        "name": "r5b_16xlarge"
-                    },
-                    {
-                        "value": "r5b.24xlarge",
-                        "name": "r5b_24xlarge"
-                    },
-                    {
-                        "value": "r5b.metal",
-                        "name": "r5b_metal"
-                    },
-                    {
-                        "value": "r5d.large",
-                        "name": "r5d_large"
-                    },
-                    {
-                        "value": "r5d.xlarge",
-                        "name": "r5d_xlarge"
-                    },
-                    {
-                        "value": "r5d.2xlarge",
-                        "name": "r5d_2xlarge"
-                    },
-                    {
-                        "value": "r5d.4xlarge",
-                        "name": "r5d_4xlarge"
-                    },
-                    {
-                        "value": "r5d.8xlarge",
-                        "name": "r5d_8xlarge"
-                    },
-                    {
-                        "value": "r5d.12xlarge",
-                        "name": "r5d_12xlarge"
-                    },
-                    {
-                        "value": "r5d.16xlarge",
-                        "name": "r5d_16xlarge"
-                    },
-                    {
-                        "value": "r5d.24xlarge",
-                        "name": "r5d_24xlarge"
-                    },
-                    {
-                        "value": "r5d.metal",
-                        "name": "r5d_metal"
-                    },
-                    {
-                        "value": "r5dn.large",
-                        "name": "r5dn_large"
-                    },
-                    {
-                        "value": "r5dn.xlarge",
-                        "name": "r5dn_xlarge"
-                    },
-                    {
-                        "value": "r5dn.2xlarge",
-                        "name": "r5dn_2xlarge"
-                    },
-                    {
-                        "value": "r5dn.4xlarge",
-                        "name": "r5dn_4xlarge"
-                    },
-                    {
-                        "value": "r5dn.8xlarge",
-                        "name": "r5dn_8xlarge"
-                    },
-                    {
-                        "value": "r5dn.12xlarge",
-                        "name": "r5dn_12xlarge"
-                    },
-                    {
-                        "value": "r5dn.16xlarge",
-                        "name": "r5dn_16xlarge"
-                    },
-                    {
-                        "value": "r5dn.24xlarge",
-                        "name": "r5dn_24xlarge"
-                    },
-                    {
-                        "value": "r5dn.metal",
-                        "name": "r5dn_metal"
-                    },
-                    {
-                        "value": "r5n.large",
-                        "name": "r5n_large"
-                    },
-                    {
-                        "value": "r5n.xlarge",
-                        "name": "r5n_xlarge"
-                    },
-                    {
-                        "value": "r5n.2xlarge",
-                        "name": "r5n_2xlarge"
-                    },
-                    {
-                        "value": "r5n.4xlarge",
-                        "name": "r5n_4xlarge"
-                    },
-                    {
-                        "value": "r5n.8xlarge",
-                        "name": "r5n_8xlarge"
-                    },
-                    {
-                        "value": "r5n.12xlarge",
-                        "name": "r5n_12xlarge"
-                    },
-                    {
-                        "value": "r5n.16xlarge",
-                        "name": "r5n_16xlarge"
-                    },
-                    {
-                        "value": "r5n.24xlarge",
-                        "name": "r5n_24xlarge"
-                    },
-                    {
-                        "value": "r5n.metal",
-                        "name": "r5n_metal"
-                    },
-                    {
-                        "value": "r6g.medium",
-                        "name": "r6g_medium"
-                    },
-                    {
-                        "value": "r6g.large",
-                        "name": "r6g_large"
-                    },
-                    {
-                        "value": "r6g.xlarge",
-                        "name": "r6g_xlarge"
-                    },
-                    {
-                        "value": "r6g.2xlarge",
-                        "name": "r6g_2xlarge"
-                    },
-                    {
-                        "value": "r6g.4xlarge",
-                        "name": "r6g_4xlarge"
-                    },
-                    {
-                        "value": "r6g.8xlarge",
-                        "name": "r6g_8xlarge"
-                    },
-                    {
-                        "value": "r6g.12xlarge",
-                        "name": "r6g_12xlarge"
-                    },
-                    {
-                        "value": "r6g.16xlarge",
-                        "name": "r6g_16xlarge"
-                    },
-                    {
-                        "value": "r6g.metal",
-                        "name": "r6g_metal"
-                    },
-                    {
-                        "value": "r6gd.medium",
-                        "name": "r6gd_medium"
-                    },
-                    {
-                        "value": "r6gd.large",
-                        "name": "r6gd_large"
-                    },
-                    {
-                        "value": "r6gd.xlarge",
-                        "name": "r6gd_xlarge"
-                    },
-                    {
-                        "value": "r6gd.2xlarge",
-                        "name": "r6gd_2xlarge"
-                    },
-                    {
-                        "value": "r6gd.4xlarge",
-                        "name": "r6gd_4xlarge"
-                    },
-                    {
-                        "value": "r6gd.8xlarge",
-                        "name": "r6gd_8xlarge"
-                    },
-                    {
-                        "value": "r6gd.12xlarge",
-                        "name": "r6gd_12xlarge"
-                    },
-                    {
-                        "value": "r6gd.16xlarge",
-                        "name": "r6gd_16xlarge"
-                    },
-                    {
-                        "value": "r6gd.metal",
-                        "name": "r6gd_metal"
-                    },
-                    {
-                        "value": "r6i.large",
-                        "name": "r6i_large"
-                    },
-                    {
-                        "value": "r6i.xlarge",
-                        "name": "r6i_xlarge"
-                    },
-                    {
-                        "value": "r6i.2xlarge",
-                        "name": "r6i_2xlarge"
-                    },
-                    {
-                        "value": "r6i.4xlarge",
-                        "name": "r6i_4xlarge"
-                    },
-                    {
-                        "value": "r6i.8xlarge",
-                        "name": "r6i_8xlarge"
-                    },
-                    {
-                        "value": "r6i.12xlarge",
-                        "name": "r6i_12xlarge"
-                    },
-                    {
-                        "value": "r6i.16xlarge",
-                        "name": "r6i_16xlarge"
-                    },
-                    {
-                        "value": "r6i.24xlarge",
-                        "name": "r6i_24xlarge"
-                    },
-                    {
-                        "value": "r6i.32xlarge",
-                        "name": "r6i_32xlarge"
-                    },
-                    {
-                        "value": "r6i.metal",
-                        "name": "r6i_metal"
-                    },
-                    {
-                        "value": "t1.micro",
-                        "name": "t1_micro"
-                    },
-                    {
-                        "value": "t2.nano",
-                        "name": "t2_nano"
-                    },
-                    {
-                        "value": "t2.micro",
-                        "name": "t2_micro"
-                    },
-                    {
-                        "value": "t2.small",
-                        "name": "t2_small"
-                    },
-                    {
-                        "value": "t2.medium",
-                        "name": "t2_medium"
-                    },
-                    {
-                        "value": "t2.large",
-                        "name": "t2_large"
-                    },
-                    {
-                        "value": "t2.xlarge",
-                        "name": "t2_xlarge"
-                    },
-                    {
-                        "value": "t2.2xlarge",
-                        "name": "t2_2xlarge"
-                    },
-                    {
-                        "value": "t3.nano",
-                        "name": "t3_nano"
-                    },
-                    {
-                        "value": "t3.micro",
-                        "name": "t3_micro"
-                    },
-                    {
-                        "value": "t3.small",
-                        "name": "t3_small"
-                    },
-                    {
-                        "value": "t3.medium",
-                        "name": "t3_medium"
-                    },
-                    {
-                        "value": "t3.large",
-                        "name": "t3_large"
-                    },
-                    {
-                        "value": "t3.xlarge",
-                        "name": "t3_xlarge"
-                    },
-                    {
-                        "value": "t3.2xlarge",
-                        "name": "t3_2xlarge"
-                    },
-                    {
-                        "value": "t3a.nano",
-                        "name": "t3a_nano"
-                    },
-                    {
-                        "value": "t3a.micro",
-                        "name": "t3a_micro"
-                    },
-                    {
-                        "value": "t3a.small",
-                        "name": "t3a_small"
-                    },
-                    {
-                        "value": "t3a.medium",
-                        "name": "t3a_medium"
-                    },
-                    {
-                        "value": "t3a.large",
-                        "name": "t3a_large"
-                    },
-                    {
-                        "value": "t3a.xlarge",
-                        "name": "t3a_xlarge"
-                    },
-                    {
-                        "value": "t3a.2xlarge",
-                        "name": "t3a_2xlarge"
-                    },
-                    {
-                        "value": "t4g.nano",
-                        "name": "t4g_nano"
-                    },
-                    {
-                        "value": "t4g.micro",
-                        "name": "t4g_micro"
-                    },
-                    {
-                        "value": "t4g.small",
-                        "name": "t4g_small"
-                    },
-                    {
-                        "value": "t4g.medium",
-                        "name": "t4g_medium"
-                    },
-                    {
-                        "value": "t4g.large",
-                        "name": "t4g_large"
-                    },
-                    {
-                        "value": "t4g.xlarge",
-                        "name": "t4g_xlarge"
-                    },
-                    {
-                        "value": "t4g.2xlarge",
-                        "name": "t4g_2xlarge"
-                    },
-                    {
-                        "value": "u-6tb1.56xlarge",
-                        "name": "u_6tb1_56xlarge"
-                    },
-                    {
-                        "value": "u-6tb1.112xlarge",
-                        "name": "u_6tb1_112xlarge"
-                    },
-                    {
-                        "value": "u-9tb1.112xlarge",
-                        "name": "u_9tb1_112xlarge"
-                    },
-                    {
-                        "value": "u-12tb1.112xlarge",
-                        "name": "u_12tb1_112xlarge"
-                    },
-                    {
-                        "value": "u-6tb1.metal",
-                        "name": "u_6tb1_metal"
-                    },
-                    {
-                        "value": "u-9tb1.metal",
-                        "name": "u_9tb1_metal"
-                    },
-                    {
-                        "value": "u-12tb1.metal",
-                        "name": "u_12tb1_metal"
-                    },
-                    {
-                        "value": "u-18tb1.metal",
-                        "name": "u_18tb1_metal"
-                    },
-                    {
-                        "value": "u-24tb1.metal",
-                        "name": "u_24tb1_metal"
-                    },
-                    {
-                        "value": "vt1.3xlarge",
-                        "name": "vt1_3xlarge"
-                    },
-                    {
-                        "value": "vt1.6xlarge",
-                        "name": "vt1_6xlarge"
-                    },
-                    {
-                        "value": "vt1.24xlarge",
-                        "name": "vt1_24xlarge"
-                    },
-                    {
-                        "value": "x1.16xlarge",
-                        "name": "x1_16xlarge"
-                    },
-                    {
-                        "value": "x1.32xlarge",
-                        "name": "x1_32xlarge"
-                    },
-                    {
-                        "value": "x1e.xlarge",
-                        "name": "x1e_xlarge"
-                    },
-                    {
-                        "value": "x1e.2xlarge",
-                        "name": "x1e_2xlarge"
-                    },
-                    {
-                        "value": "x1e.4xlarge",
-                        "name": "x1e_4xlarge"
-                    },
-                    {
-                        "value": "x1e.8xlarge",
-                        "name": "x1e_8xlarge"
-                    },
-                    {
-                        "value": "x1e.16xlarge",
-                        "name": "x1e_16xlarge"
-                    },
-                    {
-                        "value": "x1e.32xlarge",
-                        "name": "x1e_32xlarge"
-                    },
-                    {
-                        "value": "x2iezn.2xlarge",
-                        "name": "x2iezn_2xlarge"
-                    },
-                    {
-                        "value": "x2iezn.4xlarge",
-                        "name": "x2iezn_4xlarge"
-                    },
-                    {
-                        "value": "x2iezn.6xlarge",
-                        "name": "x2iezn_6xlarge"
-                    },
-                    {
-                        "value": "x2iezn.8xlarge",
-                        "name": "x2iezn_8xlarge"
-                    },
-                    {
-                        "value": "x2iezn.12xlarge",
-                        "name": "x2iezn_12xlarge"
-                    },
-                    {
-                        "value": "x2iezn.metal",
-                        "name": "x2iezn_metal"
-                    },
-                    {
-                        "value": "x2gd.medium",
-                        "name": "x2gd_medium"
-                    },
-                    {
-                        "value": "x2gd.large",
-                        "name": "x2gd_large"
-                    },
-                    {
-                        "value": "x2gd.xlarge",
-                        "name": "x2gd_xlarge"
-                    },
-                    {
-                        "value": "x2gd.2xlarge",
-                        "name": "x2gd_2xlarge"
-                    },
-                    {
-                        "value": "x2gd.4xlarge",
-                        "name": "x2gd_4xlarge"
-                    },
-                    {
-                        "value": "x2gd.8xlarge",
-                        "name": "x2gd_8xlarge"
-                    },
-                    {
-                        "value": "x2gd.12xlarge",
-                        "name": "x2gd_12xlarge"
-                    },
-                    {
-                        "value": "x2gd.16xlarge",
-                        "name": "x2gd_16xlarge"
-                    },
-                    {
-                        "value": "x2gd.metal",
-                        "name": "x2gd_metal"
-                    },
-                    {
-                        "value": "z1d.large",
-                        "name": "z1d_large"
-                    },
-                    {
-                        "value": "z1d.xlarge",
-                        "name": "z1d_xlarge"
-                    },
-                    {
-                        "value": "z1d.2xlarge",
-                        "name": "z1d_2xlarge"
-                    },
-                    {
-                        "value": "z1d.3xlarge",
-                        "name": "z1d_3xlarge"
-                    },
-                    {
-                        "value": "z1d.6xlarge",
-                        "name": "z1d_6xlarge"
-                    },
-                    {
-                        "value": "z1d.12xlarge",
-                        "name": "z1d_12xlarge"
-                    },
-                    {
-                        "value": "z1d.metal",
-                        "name": "z1d_metal"
-                    },
-                    {
-                        "value": "x2idn.16xlarge",
-                        "name": "x2idn_16xlarge"
-                    },
-                    {
-                        "value": "x2idn.24xlarge",
-                        "name": "x2idn_24xlarge"
-                    },
-                    {
-                        "value": "x2idn.32xlarge",
-                        "name": "x2idn_32xlarge"
-                    },
-                    {
-                        "value": "x2iedn.xlarge",
-                        "name": "x2iedn_xlarge"
-                    },
-                    {
-                        "value": "x2iedn.2xlarge",
-                        "name": "x2iedn_2xlarge"
-                    },
-                    {
-                        "value": "x2iedn.4xlarge",
-                        "name": "x2iedn_4xlarge"
-                    },
-                    {
-                        "value": "x2iedn.8xlarge",
-                        "name": "x2iedn_8xlarge"
-                    },
-                    {
-                        "value": "x2iedn.16xlarge",
-                        "name": "x2iedn_16xlarge"
-                    },
-                    {
-                        "value": "x2iedn.24xlarge",
-                        "name": "x2iedn_24xlarge"
-                    },
-                    {
-                        "value": "x2iedn.32xlarge",
-                        "name": "x2iedn_32xlarge"
-                    },
-                    {
-                        "value": "c6a.large",
-                        "name": "c6a_large"
-                    },
-                    {
-                        "value": "c6a.xlarge",
-                        "name": "c6a_xlarge"
-                    },
-                    {
-                        "value": "c6a.2xlarge",
-                        "name": "c6a_2xlarge"
-                    },
-                    {
-                        "value": "c6a.4xlarge",
-                        "name": "c6a_4xlarge"
-                    },
-                    {
-                        "value": "c6a.8xlarge",
-                        "name": "c6a_8xlarge"
-                    },
-                    {
-                        "value": "c6a.12xlarge",
-                        "name": "c6a_12xlarge"
-                    },
-                    {
-                        "value": "c6a.16xlarge",
-                        "name": "c6a_16xlarge"
-                    },
-                    {
-                        "value": "c6a.24xlarge",
-                        "name": "c6a_24xlarge"
-                    },
-                    {
-                        "value": "c6a.32xlarge",
-                        "name": "c6a_32xlarge"
-                    },
-                    {
-                        "value": "c6a.48xlarge",
-                        "name": "c6a_48xlarge"
-                    },
-                    {
-                        "value": "c6a.metal",
-                        "name": "c6a_metal"
-                    },
-                    {
-                        "value": "m6a.metal",
-                        "name": "m6a_metal"
-                    },
-                    {
-                        "value": "i4i.large",
-                        "name": "i4i_large"
-                    },
-                    {
-                        "value": "i4i.xlarge",
-                        "name": "i4i_xlarge"
-                    },
-                    {
-                        "value": "i4i.2xlarge",
-                        "name": "i4i_2xlarge"
-                    },
-                    {
-                        "value": "i4i.4xlarge",
-                        "name": "i4i_4xlarge"
-                    },
-                    {
-                        "value": "i4i.8xlarge",
-                        "name": "i4i_8xlarge"
-                    },
-                    {
-                        "value": "i4i.16xlarge",
-                        "name": "i4i_16xlarge"
-                    },
-                    {
-                        "value": "i4i.32xlarge",
-                        "name": "i4i_32xlarge"
-                    },
-                    {
-                        "value": "i4i.metal",
-                        "name": "i4i_metal"
-                    },
-                    {
-                        "value": "x2idn.metal",
-                        "name": "x2idn_metal"
-                    },
-                    {
-                        "value": "x2iedn.metal",
-                        "name": "x2iedn_metal"
-                    },
-                    {
-                        "value": "c7g.medium",
-                        "name": "c7g_medium"
-                    },
-                    {
-                        "value": "c7g.large",
-                        "name": "c7g_large"
-                    },
-                    {
-                        "value": "c7g.xlarge",
-                        "name": "c7g_xlarge"
-                    },
-                    {
-                        "value": "c7g.2xlarge",
-                        "name": "c7g_2xlarge"
-                    },
-                    {
-                        "value": "c7g.4xlarge",
-                        "name": "c7g_4xlarge"
-                    },
-                    {
-                        "value": "c7g.8xlarge",
-                        "name": "c7g_8xlarge"
-                    },
-                    {
-                        "value": "c7g.12xlarge",
-                        "name": "c7g_12xlarge"
-                    },
-                    {
-                        "value": "c7g.16xlarge",
-                        "name": "c7g_16xlarge"
-                    },
-                    {
-                        "value": "mac2.metal",
-                        "name": "mac2_metal"
-                    },
-                    {
-                        "value": "c6id.large",
-                        "name": "c6id_large"
-                    },
-                    {
-                        "value": "c6id.xlarge",
-                        "name": "c6id_xlarge"
-                    },
-                    {
-                        "value": "c6id.2xlarge",
-                        "name": "c6id_2xlarge"
-                    },
-                    {
-                        "value": "c6id.4xlarge",
-                        "name": "c6id_4xlarge"
-                    },
-                    {
-                        "value": "c6id.8xlarge",
-                        "name": "c6id_8xlarge"
-                    },
-                    {
-                        "value": "c6id.12xlarge",
-                        "name": "c6id_12xlarge"
-                    },
-                    {
-                        "value": "c6id.16xlarge",
-                        "name": "c6id_16xlarge"
-                    },
-                    {
-                        "value": "c6id.24xlarge",
-                        "name": "c6id_24xlarge"
-                    },
-                    {
-                        "value": "c6id.32xlarge",
-                        "name": "c6id_32xlarge"
-                    },
-                    {
-                        "value": "c6id.metal",
-                        "name": "c6id_metal"
-                    },
-                    {
-                        "value": "m6id.large",
-                        "name": "m6id_large"
-                    },
-                    {
-                        "value": "m6id.xlarge",
-                        "name": "m6id_xlarge"
-                    },
-                    {
-                        "value": "m6id.2xlarge",
-                        "name": "m6id_2xlarge"
-                    },
-                    {
-                        "value": "m6id.4xlarge",
-                        "name": "m6id_4xlarge"
-                    },
-                    {
-                        "value": "m6id.8xlarge",
-                        "name": "m6id_8xlarge"
-                    },
-                    {
-                        "value": "m6id.12xlarge",
-                        "name": "m6id_12xlarge"
-                    },
-                    {
-                        "value": "m6id.16xlarge",
-                        "name": "m6id_16xlarge"
-                    },
-                    {
-                        "value": "m6id.24xlarge",
-                        "name": "m6id_24xlarge"
-                    },
-                    {
-                        "value": "m6id.32xlarge",
-                        "name": "m6id_32xlarge"
-                    },
-                    {
-                        "value": "m6id.metal",
-                        "name": "m6id_metal"
-                    },
-                    {
-                        "value": "r6id.large",
-                        "name": "r6id_large"
-                    },
-                    {
-                        "value": "r6id.xlarge",
-                        "name": "r6id_xlarge"
-                    },
-                    {
-                        "value": "r6id.2xlarge",
-                        "name": "r6id_2xlarge"
-                    },
-                    {
-                        "value": "r6id.4xlarge",
-                        "name": "r6id_4xlarge"
-                    },
-                    {
-                        "value": "r6id.8xlarge",
-                        "name": "r6id_8xlarge"
-                    },
-                    {
-                        "value": "r6id.12xlarge",
-                        "name": "r6id_12xlarge"
-                    },
-                    {
-                        "value": "r6id.16xlarge",
-                        "name": "r6id_16xlarge"
-                    },
-                    {
-                        "value": "r6id.24xlarge",
-                        "name": "r6id_24xlarge"
-                    },
-                    {
-                        "value": "r6id.32xlarge",
-                        "name": "r6id_32xlarge"
-                    },
-                    {
-                        "value": "r6id.metal",
-                        "name": "r6id_metal"
-                    },
-                    {
-                        "value": "r6a.large",
-                        "name": "r6a_large"
-                    },
-                    {
-                        "value": "r6a.xlarge",
-                        "name": "r6a_xlarge"
-                    },
-                    {
-                        "value": "r6a.2xlarge",
-                        "name": "r6a_2xlarge"
-                    },
-                    {
-                        "value": "r6a.4xlarge",
-                        "name": "r6a_4xlarge"
-                    },
-                    {
-                        "value": "r6a.8xlarge",
-                        "name": "r6a_8xlarge"
-                    },
-                    {
-                        "value": "r6a.12xlarge",
-                        "name": "r6a_12xlarge"
-                    },
-                    {
-                        "value": "r6a.16xlarge",
-                        "name": "r6a_16xlarge"
-                    },
-                    {
-                        "value": "r6a.24xlarge",
-                        "name": "r6a_24xlarge"
-                    },
-                    {
-                        "value": "r6a.32xlarge",
-                        "name": "r6a_32xlarge"
-                    },
-                    {
-                        "value": "r6a.48xlarge",
-                        "name": "r6a_48xlarge"
-                    },
-                    {
-                        "value": "r6a.metal",
-                        "name": "r6a_metal"
-                    },
-                    {
-                        "value": "p4de.24xlarge",
-                        "name": "p4de_24xlarge"
+            "type": "enum",
+            "members": {
+                "a1_medium": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "a1.medium"
+                    }
+                },
+                "a1_large": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "a1.large"
+                    }
+                },
+                "a1_xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "a1.xlarge"
+                    }
+                },
+                "a1_2xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "a1.2xlarge"
+                    }
+                },
+                "a1_4xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "a1.4xlarge"
+                    }
+                },
+                "a1_metal": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "a1.metal"
+                    }
+                },
+                "c1_medium": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c1.medium"
+                    }
+                },
+                "c1_xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c1.xlarge"
+                    }
+                },
+                "c3_large": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c3.large"
+                    }
+                },
+                "c3_xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c3.xlarge"
+                    }
+                },
+                "c3_2xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c3.2xlarge"
+                    }
+                },
+                "c3_4xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c3.4xlarge"
+                    }
+                },
+                "c3_8xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c3.8xlarge"
+                    }
+                },
+                "c4_large": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c4.large"
+                    }
+                },
+                "c4_xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c4.xlarge"
+                    }
+                },
+                "c4_2xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c4.2xlarge"
+                    }
+                },
+                "c4_4xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c4.4xlarge"
+                    }
+                },
+                "c4_8xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c4.8xlarge"
+                    }
+                },
+                "c5_large": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c5.large"
+                    }
+                },
+                "c5_xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c5.xlarge"
+                    }
+                },
+                "c5_2xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c5.2xlarge"
+                    }
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+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6a.48xlarge"
+                    }
+                },
+                "c6a_metal": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6a.metal"
+                    }
+                },
+                "m6a_metal": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m6a.metal"
+                    }
+                },
+                "i4i_large": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "i4i.large"
+                    }
+                },
+                "i4i_xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "i4i.xlarge"
+                    }
+                },
+                "i4i_2xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "i4i.2xlarge"
+                    }
+                },
+                "i4i_4xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "i4i.4xlarge"
+                    }
+                },
+                "i4i_8xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "i4i.8xlarge"
+                    }
+                },
+                "i4i_16xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "i4i.16xlarge"
+                    }
+                },
+                "i4i_32xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "i4i.32xlarge"
+                    }
+                },
+                "i4i_metal": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "i4i.metal"
+                    }
+                },
+                "x2idn_metal": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "x2idn.metal"
+                    }
+                },
+                "x2iedn_metal": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "x2iedn.metal"
+                    }
+                },
+                "c7g_medium": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c7g.medium"
+                    }
+                },
+                "c7g_large": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c7g.large"
+                    }
+                },
+                "c7g_xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c7g.xlarge"
+                    }
+                },
+                "c7g_2xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c7g.2xlarge"
+                    }
+                },
+                "c7g_4xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c7g.4xlarge"
+                    }
+                },
+                "c7g_8xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c7g.8xlarge"
+                    }
+                },
+                "c7g_12xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c7g.12xlarge"
+                    }
+                },
+                "c7g_16xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c7g.16xlarge"
+                    }
+                },
+                "mac2_metal": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "mac2.metal"
+                    }
+                },
+                "c6id_large": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6id.large"
+                    }
+                },
+                "c6id_xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6id.xlarge"
+                    }
+                },
+                "c6id_2xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6id.2xlarge"
+                    }
+                },
+                "c6id_4xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6id.4xlarge"
+                    }
+                },
+                "c6id_8xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6id.8xlarge"
+                    }
+                },
+                "c6id_12xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6id.12xlarge"
+                    }
+                },
+                "c6id_16xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6id.16xlarge"
+                    }
+                },
+                "c6id_24xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6id.24xlarge"
+                    }
+                },
+                "c6id_32xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6id.32xlarge"
+                    }
+                },
+                "c6id_metal": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "c6id.metal"
+                    }
+                },
+                "m6id_large": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m6id.large"
+                    }
+                },
+                "m6id_xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m6id.xlarge"
+                    }
+                },
+                "m6id_2xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m6id.2xlarge"
+                    }
+                },
+                "m6id_4xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m6id.4xlarge"
+                    }
+                },
+                "m6id_8xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m6id.8xlarge"
+                    }
+                },
+                "m6id_12xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m6id.12xlarge"
+                    }
+                },
+                "m6id_16xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m6id.16xlarge"
+                    }
+                },
+                "m6id_24xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m6id.24xlarge"
+                    }
+                },
+                "m6id_32xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m6id.32xlarge"
+                    }
+                },
+                "m6id_metal": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "m6id.metal"
+                    }
+                },
+                "r6id_large": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6id.large"
+                    }
+                },
+                "r6id_xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6id.xlarge"
+                    }
+                },
+                "r6id_2xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6id.2xlarge"
+                    }
+                },
+                "r6id_4xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6id.4xlarge"
+                    }
+                },
+                "r6id_8xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6id.8xlarge"
+                    }
+                },
+                "r6id_12xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6id.12xlarge"
+                    }
+                },
+                "r6id_16xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6id.16xlarge"
+                    }
+                },
+                "r6id_24xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6id.24xlarge"
+                    }
+                },
+                "r6id_32xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6id.32xlarge"
+                    }
+                },
+                "r6id_metal": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6id.metal"
+                    }
+                },
+                "r6a_large": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6a.large"
+                    }
+                },
+                "r6a_xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6a.xlarge"
+                    }
+                },
+                "r6a_2xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6a.2xlarge"
+                    }
+                },
+                "r6a_4xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6a.4xlarge"
+                    }
+                },
+                "r6a_8xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6a.8xlarge"
+                    }
+                },
+                "r6a_12xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6a.12xlarge"
+                    }
+                },
+                "r6a_16xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6a.16xlarge"
+                    }
+                },
+                "r6a_24xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6a.24xlarge"
+                    }
+                },
+                "r6a_32xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6a.32xlarge"
+                    }
+                },
+                "r6a_48xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6a.48xlarge"
+                    }
+                },
+                "r6a_metal": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "r6a.metal"
+                    }
+                },
+                "p4de_24xlarge": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "p4de.24xlarge"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceTypeHypervisor": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "nitro",
-                        "name": "NITRO"
-                    },
-                    {
-                        "value": "xen",
-                        "name": "XEN"
+            "type": "enum",
+            "members": {
+                "NITRO": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "nitro"
                     }
-                ]
+                },
+                "XEN": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "xen"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InstanceTypeInfo": {
@@ -49405,6 +53142,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "UsedInstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of instances the Amazon Web Services account currently has in the Capacity Reservation.</p>",
                         "smithy.api#xmlName": "usedInstanceCount"
                     }
@@ -49424,12 +53163,14 @@
             }
         },
         "com.amazonaws.ec2#Integer": {
-            "type": "integer"
+            "type": "integer",
+            "traits": {
+                "smithy.api#default": 0
+            }
         },
         "com.amazonaws.ec2#IntegerWithConstraints": {
             "type": "integer",
             "traits": {
-                "smithy.api#box": {},
                 "smithy.api#range": {
                     "min": 0
                 }
@@ -49451,33 +53192,37 @@
             }
         },
         "com.amazonaws.ec2#InterfacePermissionType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "INSTANCE-ATTACH",
-                        "name": "INSTANCE_ATTACH"
-                    },
-                    {
-                        "value": "EIP-ASSOCIATE",
-                        "name": "EIP_ASSOCIATE"
+            "type": "enum",
+            "members": {
+                "INSTANCE_ATTACH": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "INSTANCE-ATTACH"
                     }
-                ]
+                },
+                "EIP_ASSOCIATE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "EIP-ASSOCIATE"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InterfaceProtocolType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "VLAN",
-                        "name": "VLAN"
-                    },
-                    {
-                        "value": "GRE",
-                        "name": "GRE"
+            "type": "enum",
+            "members": {
+                "VLAN": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "VLAN"
                     }
-                ]
+                },
+                "GRE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "GRE"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#InternetGateway": {
@@ -49594,22 +53339,26 @@
             }
         },
         "com.amazonaws.ec2#IpAddressType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ipv4",
-                        "name": "ipv4"
-                    },
-                    {
-                        "value": "dualstack",
-                        "name": "dualstack"
-                    },
-                    {
-                        "value": "ipv6",
-                        "name": "ipv6"
+            "type": "enum",
+            "members": {
+                "ipv4": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv4"
                     }
-                ]
+                },
+                "dualstack": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "dualstack"
+                    }
+                },
+                "ipv6": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv6"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IpPermission": {
@@ -49619,6 +53368,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FromPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The start of port range for the TCP and UDP protocols, or an ICMP/ICMPv6 type number.\n        A value of <code>-1</code> indicates all ICMP/ICMPv6 types. If you specify all\n\t\tICMP/ICMPv6 types, you must specify all codes.</p>",
                         "smithy.api#xmlName": "fromPort"
                     }
@@ -49659,6 +53410,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ToPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The end of port range for the TCP and UDP protocols, or an ICMP/ICMPv6 code. A value\n\t\tof <code>-1</code> indicates all ICMP/ICMPv6 codes. If you specify all ICMP/ICMPv6 types, \n        you must specify all codes.</p>",
                         "smithy.api#xmlName": "toPort"
                     }
@@ -49791,6 +53544,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ScopeCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of scopes in the IPAM. The scope quota is 5. For more information on quotas, see <a href=\"https://docs.aws.amazon.com/vpc/latest/ipam/quotas-ipam.html\">Quotas in IPAM</a> in the <i>Amazon VPC IPAM User Guide</i>.\n      </p>",
                         "smithy.api#xmlName": "scopeCount"
                     }
@@ -49835,6 +53590,7 @@
         "com.amazonaws.ec2#IpamAddressHistoryMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 1000
@@ -49947,30 +53703,38 @@
             }
         },
         "com.amazonaws.ec2#IpamAddressHistoryResourceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "eip",
-                        "name": "eip"
-                    },
-                    {
-                        "value": "vpc",
-                        "name": "vpc"
-                    },
-                    {
-                        "value": "subnet",
-                        "name": "subnet"
-                    },
-                    {
-                        "value": "network-interface",
-                        "name": "network_interface"
-                    },
-                    {
-                        "value": "instance",
-                        "name": "instance"
+            "type": "enum",
+            "members": {
+                "eip": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "eip"
                     }
-                ]
+                },
+                "vpc": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vpc"
+                    }
+                },
+                "subnet": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "subnet"
+                    }
+                },
+                "network_interface": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "network-interface"
+                    }
+                },
+                "instance": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instance"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IpamCidrAuthorizationContext": {
@@ -49994,53 +53758,64 @@
             }
         },
         "com.amazonaws.ec2#IpamComplianceStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "compliant",
-                        "name": "compliant"
-                    },
-                    {
-                        "value": "noncompliant",
-                        "name": "noncompliant"
-                    },
-                    {
-                        "value": "unmanaged",
-                        "name": "unmanaged"
-                    },
-                    {
-                        "value": "ignored",
-                        "name": "ignored"
+            "type": "enum",
+            "members": {
+                "compliant": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "compliant"
                     }
-                ]
+                },
+                "noncompliant": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "noncompliant"
+                    }
+                },
+                "unmanaged": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unmanaged"
+                    }
+                },
+                "ignored": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ignored"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IpamId": {
             "type": "string"
         },
         "com.amazonaws.ec2#IpamManagementState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "managed",
-                        "name": "managed"
-                    },
-                    {
-                        "value": "unmanaged",
-                        "name": "unmanaged"
-                    },
-                    {
-                        "value": "ignored",
-                        "name": "ignored"
+            "type": "enum",
+            "members": {
+                "managed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "managed"
                     }
-                ]
+                },
+                "unmanaged": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unmanaged"
+                    }
+                },
+                "ignored": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ignored"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IpamMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -50050,6 +53825,7 @@
         "com.amazonaws.ec2#IpamNetmaskLength": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 0,
                     "max": 128
@@ -50082,22 +53858,26 @@
             }
         },
         "com.amazonaws.ec2#IpamOverlapStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "overlapping",
-                        "name": "overlapping"
-                    },
-                    {
-                        "value": "nonoverlapping",
-                        "name": "nonoverlapping"
-                    },
-                    {
-                        "value": "ignored",
-                        "name": "ignored"
+            "type": "enum",
+            "members": {
+                "overlapping": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "overlapping"
                     }
-                ]
+                },
+                "nonoverlapping": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "nonoverlapping"
+                    }
+                },
+                "ignored": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ignored"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IpamPool": {
@@ -50179,6 +53959,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PoolDepth",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The depth of pools in your IPAM pool. The pool depth quota is 10. For more information, see <a href=\"https://docs.aws.amazon.com/vpc/latest/ipam/quotas-ipam.html\">Quotas in IPAM</a> in the <i>Amazon VPC IPAM User Guide</i>.\n      </p>",
                         "smithy.api#xmlName": "poolDepth"
                     }
@@ -50211,6 +53993,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AutoImport",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If selected, IPAM will continuously look for resources within the CIDR range of this pool \n         and automatically import them as allocations into your IPAM. The CIDRs that will be allocated for\n         these resources must not already be allocated to other resources in order for the import to succeed. IPAM will import \n         a CIDR regardless of its compliance with the pool's allocation rules, so a resource might be imported and subsequently \n         marked as noncompliant. If IPAM discovers multiple CIDRs that overlap, IPAM will import the largest CIDR only. If IPAM \n         discovers multiple CIDRs with matching CIDRs, IPAM will randomly import one of them only.\n      </p>\n         <p>A locale must be set on the pool for this feature to work.</p>",
                         "smithy.api#xmlName": "autoImport"
                     }
@@ -50219,6 +54003,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PubliclyAdvertisable",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Determines if a pool is publicly advertisable. This option is not available for pools with AddressFamily set to <code>ipv4</code>.</p>",
                         "smithy.api#xmlName": "publiclyAdvertisable"
                     }
@@ -50235,6 +54021,8 @@
                     "target": "com.amazonaws.ec2#IpamNetmaskLength",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AllocationMinNetmaskLength",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum netmask length required for CIDR allocations in this IPAM pool to be compliant. The minimum netmask length must be less than the maximum netmask length. Possible netmask lengths for IPv4 addresses are 0 - 32. Possible netmask lengths for IPv6 addresses are  0 - 128.</p>",
                         "smithy.api#xmlName": "allocationMinNetmaskLength"
                     }
@@ -50243,6 +54031,8 @@
                     "target": "com.amazonaws.ec2#IpamNetmaskLength",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AllocationMaxNetmaskLength",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum netmask length possible for CIDR allocations in this IPAM pool to be compliant. The maximum netmask length must be greater than the minimum netmask length. Possible netmask lengths for IPv4 addresses are 0 - 32. Possible netmask lengths for IPv6 addresses are  0 - 128.</p>",
                         "smithy.api#xmlName": "allocationMaxNetmaskLength"
                     }
@@ -50251,6 +54041,8 @@
                     "target": "com.amazonaws.ec2#IpamNetmaskLength",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AllocationDefaultNetmaskLength",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The default netmask length for allocations added to this pool. If, for example, the CIDR assigned to this pool is 10.0.0.0/8 and \n         you enter 16 here, new allocations will default to 10.0.0.0/16.</p>",
                         "smithy.api#xmlName": "allocationDefaultNetmaskLength"
                     }
@@ -50361,26 +54153,32 @@
             "type": "string"
         },
         "com.amazonaws.ec2#IpamPoolAllocationResourceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ipam-pool",
-                        "name": "ipam_pool"
-                    },
-                    {
-                        "value": "vpc",
-                        "name": "vpc"
-                    },
-                    {
-                        "value": "ec2-public-ipv4-pool",
-                        "name": "ec2_public_ipv4_pool"
-                    },
-                    {
-                        "value": "custom",
-                        "name": "custom"
+            "type": "enum",
+            "members": {
+                "ipam_pool": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipam-pool"
                     }
-                ]
+                },
+                "vpc": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vpc"
+                    }
+                },
+                "ec2_public_ipv4_pool": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ec2-public-ipv4-pool"
+                    }
+                },
+                "custom": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "custom"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IpamPoolAllocationSet": {
@@ -50393,14 +54191,14 @@
             }
         },
         "com.amazonaws.ec2#IpamPoolAwsService": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ec2",
-                        "name": "ec2"
+            "type": "enum",
+            "members": {
+                "ec2": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ec2"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#IpamPoolCidr": {
@@ -50436,14 +54234,14 @@
             }
         },
         "com.amazonaws.ec2#IpamPoolCidrFailureCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "cidr-not-available",
-                        "name": "cidr_not_available"
+            "type": "enum",
+            "members": {
+                "cidr_not_available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cidr-not-available"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#IpamPoolCidrFailureReason": {
@@ -50480,42 +54278,56 @@
             }
         },
         "com.amazonaws.ec2#IpamPoolCidrState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending-provision",
-                        "name": "pending_provision"
-                    },
-                    {
-                        "value": "provisioned",
-                        "name": "provisioned"
-                    },
-                    {
-                        "value": "failed-provision",
-                        "name": "failed_provision"
-                    },
-                    {
-                        "value": "pending-deprovision",
-                        "name": "pending_deprovision"
-                    },
-                    {
-                        "value": "deprovisioned",
-                        "name": "deprovisioned"
-                    },
-                    {
-                        "value": "failed-deprovision",
-                        "name": "failed_deprovision"
-                    },
-                    {
-                        "value": "pending-import",
-                        "name": "pending_import"
-                    },
-                    {
-                        "value": "failed-import",
-                        "name": "failed_import"
+            "type": "enum",
+            "members": {
+                "pending_provision": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending-provision"
                     }
-                ]
+                },
+                "provisioned": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "provisioned"
+                    }
+                },
+                "failed_provision": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed-provision"
+                    }
+                },
+                "pending_deprovision": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending-deprovision"
+                    }
+                },
+                "deprovisioned": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deprovisioned"
+                    }
+                },
+                "failed_deprovision": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed-deprovision"
+                    }
+                },
+                "pending_import": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending-import"
+                    }
+                },
+                "failed_import": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed-import"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IpamPoolId": {
@@ -50531,58 +54343,80 @@
             }
         },
         "com.amazonaws.ec2#IpamPoolState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "create-in-progress",
-                        "name": "create_in_progress"
-                    },
-                    {
-                        "value": "create-complete",
-                        "name": "create_complete"
-                    },
-                    {
-                        "value": "create-failed",
-                        "name": "create_failed"
-                    },
-                    {
-                        "value": "modify-in-progress",
-                        "name": "modify_in_progress"
-                    },
-                    {
-                        "value": "modify-complete",
-                        "name": "modify_complete"
-                    },
-                    {
-                        "value": "modify-failed",
-                        "name": "modify_failed"
-                    },
-                    {
-                        "value": "delete-in-progress",
-                        "name": "delete_in_progress"
-                    },
-                    {
-                        "value": "delete-complete",
-                        "name": "delete_complete"
-                    },
-                    {
-                        "value": "delete-failed",
-                        "name": "delete_failed"
-                    },
-                    {
-                        "value": "isolate-in-progress",
-                        "name": "isolate_in_progress"
-                    },
-                    {
-                        "value": "isolate-complete",
-                        "name": "isolate_complete"
-                    },
-                    {
-                        "value": "restore-in-progress",
-                        "name": "restore_in_progress"
+            "type": "enum",
+            "members": {
+                "create_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-in-progress"
                     }
-                ]
+                },
+                "create_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-complete"
+                    }
+                },
+                "create_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-failed"
+                    }
+                },
+                "modify_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-in-progress"
+                    }
+                },
+                "modify_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-complete"
+                    }
+                },
+                "modify_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-failed"
+                    }
+                },
+                "delete_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-in-progress"
+                    }
+                },
+                "delete_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-complete"
+                    }
+                },
+                "delete_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-failed"
+                    }
+                },
+                "isolate_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "isolate-in-progress"
+                    }
+                },
+                "isolate_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "isolate-complete"
+                    }
+                },
+                "restore_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "restore-in-progress"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IpamResourceCidr": {
@@ -50756,30 +54590,38 @@
             }
         },
         "com.amazonaws.ec2#IpamResourceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "vpc",
-                        "name": "vpc"
-                    },
-                    {
-                        "value": "subnet",
-                        "name": "subnet"
-                    },
-                    {
-                        "value": "eip",
-                        "name": "eip"
-                    },
-                    {
-                        "value": "public-ipv4-pool",
-                        "name": "public_ipv4_pool"
-                    },
-                    {
-                        "value": "ipv6-pool",
-                        "name": "ipv6_pool"
+            "type": "enum",
+            "members": {
+                "vpc": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vpc"
                     }
-                ]
+                },
+                "subnet": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "subnet"
+                    }
+                },
+                "eip": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "eip"
+                    }
+                },
+                "public_ipv4_pool": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "public-ipv4-pool"
+                    }
+                },
+                "ipv6_pool": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv6-pool"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IpamScope": {
@@ -50837,6 +54679,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "IsDefault",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Defines if the scope is the default scope or not.</p>",
                         "smithy.api#xmlName": "isDefault"
                     }
@@ -50853,6 +54697,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PoolCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of pools in the scope.</p>",
                         "smithy.api#xmlName": "poolCount"
                     }
@@ -50891,73 +54737,97 @@
             }
         },
         "com.amazonaws.ec2#IpamScopeState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "create-in-progress",
-                        "name": "create_in_progress"
-                    },
-                    {
-                        "value": "create-complete",
-                        "name": "create_complete"
-                    },
-                    {
-                        "value": "create-failed",
-                        "name": "create_failed"
-                    },
-                    {
-                        "value": "modify-in-progress",
-                        "name": "modify_in_progress"
-                    },
-                    {
-                        "value": "modify-complete",
-                        "name": "modify_complete"
-                    },
-                    {
-                        "value": "modify-failed",
-                        "name": "modify_failed"
-                    },
-                    {
-                        "value": "delete-in-progress",
-                        "name": "delete_in_progress"
-                    },
-                    {
-                        "value": "delete-complete",
-                        "name": "delete_complete"
-                    },
-                    {
-                        "value": "delete-failed",
-                        "name": "delete_failed"
-                    },
-                    {
-                        "value": "isolate-in-progress",
-                        "name": "isolate_in_progress"
-                    },
-                    {
-                        "value": "isolate-complete",
-                        "name": "isolate_complete"
-                    },
-                    {
-                        "value": "restore-in-progress",
-                        "name": "restore_in_progress"
+            "type": "enum",
+            "members": {
+                "create_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-in-progress"
                     }
-                ]
+                },
+                "create_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-complete"
+                    }
+                },
+                "create_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-failed"
+                    }
+                },
+                "modify_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-in-progress"
+                    }
+                },
+                "modify_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-complete"
+                    }
+                },
+                "modify_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-failed"
+                    }
+                },
+                "delete_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-in-progress"
+                    }
+                },
+                "delete_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-complete"
+                    }
+                },
+                "delete_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-failed"
+                    }
+                },
+                "isolate_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "isolate-in-progress"
+                    }
+                },
+                "isolate_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "isolate-complete"
+                    }
+                },
+                "restore_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "restore-in-progress"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IpamScopeType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "public",
-                        "name": "public"
-                    },
-                    {
-                        "value": "private",
-                        "name": "private"
+            "type": "enum",
+            "members": {
+                "public": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "public"
                     }
-                ]
+                },
+                "private": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "private"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#IpamSet": {
@@ -50970,58 +54840,80 @@
             }
         },
         "com.amazonaws.ec2#IpamState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "create-in-progress",
-                        "name": "create_in_progress"
-                    },
-                    {
-                        "value": "create-complete",
-                        "name": "create_complete"
-                    },
-                    {
-                        "value": "create-failed",
-                        "name": "create_failed"
-                    },
-                    {
-                        "value": "modify-in-progress",
-                        "name": "modify_in_progress"
-                    },
-                    {
-                        "value": "modify-complete",
-                        "name": "modify_complete"
-                    },
-                    {
-                        "value": "modify-failed",
-                        "name": "modify_failed"
-                    },
-                    {
-                        "value": "delete-in-progress",
-                        "name": "delete_in_progress"
-                    },
-                    {
-                        "value": "delete-complete",
-                        "name": "delete_complete"
-                    },
-                    {
-                        "value": "delete-failed",
-                        "name": "delete_failed"
-                    },
-                    {
-                        "value": "isolate-in-progress",
-                        "name": "isolate_in_progress"
-                    },
-                    {
-                        "value": "isolate-complete",
-                        "name": "isolate_complete"
-                    },
-                    {
-                        "value": "restore-in-progress",
-                        "name": "restore_in_progress"
+            "type": "enum",
+            "members": {
+                "create_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-in-progress"
                     }
-                ]
+                },
+                "create_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-complete"
+                    }
+                },
+                "create_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-failed"
+                    }
+                },
+                "modify_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-in-progress"
+                    }
+                },
+                "modify_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-complete"
+                    }
+                },
+                "modify_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-failed"
+                    }
+                },
+                "delete_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-in-progress"
+                    }
+                },
+                "delete_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-complete"
+                    }
+                },
+                "delete_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-failed"
+                    }
+                },
+                "isolate_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "isolate-in-progress"
+                    }
+                },
+                "isolate_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "isolate-complete"
+                    }
+                },
+                "restore_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "restore-in-progress"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#Ipv4PoolCoipId": {
@@ -51174,10 +55066,7 @@
             }
         },
         "com.amazonaws.ec2#Ipv6Flag": {
-            "type": "boolean",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "boolean"
         },
         "com.amazonaws.ec2#Ipv6Pool": {
             "type": "structure",
@@ -51234,6 +55123,7 @@
         "com.amazonaws.ec2#Ipv6PoolMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 1000
@@ -51356,36 +55246,40 @@
             }
         },
         "com.amazonaws.ec2#Ipv6SupportValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#KernelId": {
             "type": "string"
         },
         "com.amazonaws.ec2#KeyFormat": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pem",
-                        "name": "pem"
-                    },
-                    {
-                        "value": "ppk",
-                        "name": "ppk"
+            "type": "enum",
+            "members": {
+                "pem": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pem"
                     }
-                ]
+                },
+                "ppk": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ppk"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#KeyNameStringList": {
@@ -51534,18 +55428,20 @@
             "type": "string"
         },
         "com.amazonaws.ec2#KeyType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "rsa",
-                        "name": "rsa"
-                    },
-                    {
-                        "value": "ed25519",
-                        "name": "ed25519"
+            "type": "enum",
+            "members": {
+                "rsa": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "rsa"
                     }
-                ]
+                },
+                "ed25519": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ed25519"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#KmsKeyId": {
@@ -51683,6 +55579,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EbsOptimized",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the instance is optimized for EBS I/O. This optimization provides dedicated throughput to Amazon EBS and an optimized configuration stack to provide optimal EBS I/O performance. This optimization isn't available with all instance types. Additional usage charges apply when using an EBS Optimized instance.</p>\n         <p>Default: <code>false</code>\n         </p>",
                         "smithy.api#xmlName": "ebsOptimized"
                     }
@@ -51819,6 +55717,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DefaultVersionNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The version number of the default version of the launch template.</p>",
                         "smithy.api#xmlName": "defaultVersionNumber"
                     }
@@ -51827,6 +55727,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "LatestVersionNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The version number of the latest version of the launch template.</p>",
                         "smithy.api#xmlName": "latestVersionNumber"
                     }
@@ -51869,18 +55771,20 @@
             }
         },
         "com.amazonaws.ec2#LaunchTemplateAutoRecoveryState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "default",
-                        "name": "default"
-                    },
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
+            "type": "enum",
+            "members": {
+                "default": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "default"
                     }
-                ]
+                },
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LaunchTemplateBlockDeviceMapping": {
@@ -52057,6 +55961,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "CoreCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of CPU cores for the instance.</p>",
                         "smithy.api#xmlName": "coreCount"
                     }
@@ -52065,6 +55971,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ThreadsPerCore",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of threads per CPU core.</p>",
                         "smithy.api#xmlName": "threadsPerCore"
                     }
@@ -52080,12 +55988,16 @@
                 "CoreCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of CPU cores for the instance.</p>"
                     }
                 },
                 "ThreadsPerCore": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of threads per CPU core. To disable multithreading for the instance,\n            specify a value of <code>1</code>. Otherwise, specify the default value of <code>2</code>.</p>"
                     }
                 }
@@ -52101,6 +56013,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the EBS volume is encrypted.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -52109,6 +56023,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeleteOnTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the EBS volume is deleted on instance termination.</p>",
                         "smithy.api#xmlName": "deleteOnTermination"
                     }
@@ -52117,6 +56033,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Iops",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of I/O operations per second (IOPS) that the volume supports. </p>",
                         "smithy.api#xmlName": "iops"
                     }
@@ -52141,6 +56059,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VolumeSize",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the volume, in GiB.</p>",
                         "smithy.api#xmlName": "volumeSize"
                     }
@@ -52157,6 +56077,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Throughput",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The throughput that the volume supports, in MiB/s.</p>",
                         "smithy.api#xmlName": "throughput"
                     }
@@ -52172,18 +56094,24 @@
                 "Encrypted": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the EBS volume is encrypted. Encrypted volumes can only be attached\n            to instances that support Amazon EBS encryption. If you are creating a volume from a\n            snapshot, you can't specify an encryption value.</p>"
                     }
                 },
                 "DeleteOnTermination": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the EBS volume is deleted on instance termination.</p>"
                     }
                 },
                 "Iops": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of I/O operations per second (IOPS). For <code>gp3</code>,\n            <code>io1</code>, and <code>io2</code> volumes, this represents the number of IOPS that\n            are provisioned for the volume. For <code>gp2</code> volumes, this represents the\n            baseline performance of the volume and the rate at which the volume accumulates I/O\n            credits for bursting.</p>\n        <p>The following are the supported values for each volume type:</p>\n        <ul>\n            <li>\n                <p>\n                  <code>gp3</code>: 3,000-16,000 IOPS</p>\n            </li>\n            <li>\n                <p>\n                  <code>io1</code>: 100-64,000 IOPS</p>\n            </li>\n            <li>\n                <p>\n                  <code>io2</code>: 100-64,000 IOPS</p>\n            </li>\n         </ul>\n        <p>For <code>io1</code> and <code>io2</code> volumes, we guarantee\n            64,000 IOPS only for <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html#ec2-nitro-instances\">Instances built on the\n                Nitro System</a>. Other instance families guarantee performance up to\n            32,000 IOPS.</p>\n        <p>This parameter is supported for <code>io1</code>, <code>io2</code>, and <code>gp3</code> volumes only. This parameter\n            is not supported for <code>gp2</code>, <code>st1</code>, <code>sc1</code>, or <code>standard</code> volumes.</p>"
                     }
                 },
@@ -52202,6 +56130,8 @@
                 "VolumeSize": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the volume, in GiBs. You must specify either a snapshot ID or a volume\n            size. The following are the supported volumes sizes for each volume type:</p>\n        <ul>\n            <li>\n                <p>\n                  <code>gp2</code> and <code>gp3</code>: 1-16,384</p>\n            </li>\n            <li>\n                <p>\n                  <code>io1</code> and <code>io2</code>: 4-16,384</p>\n            </li>\n            <li>\n                <p>\n                  <code>st1</code> and <code>sc1</code>: 125-16,384</p>\n            </li>\n            <li>\n                <p>\n                  <code>standard</code>: 1-1,024</p>\n            </li>\n         </ul>"
                     }
                 },
@@ -52214,6 +56144,8 @@
                 "Throughput": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The throughput to provision for a <code>gp3</code> volume, with a maximum of 1,000\n            MiB/s.</p>\n        <p>Valid Range: Minimum value of 125. Maximum value of 1000.</p>"
                     }
                 }
@@ -52228,6 +56160,7 @@
                 "Type": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p> The type of elastic inference accelerator. The possible values are eia1.medium,\n            eia1.large, and eia1.xlarge. </p>",
                         "smithy.api#required": {}
                     }
@@ -52235,6 +56168,8 @@
                 "Count": {
                     "target": "com.amazonaws.ec2#LaunchTemplateElasticInferenceAcceleratorCount",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p> The number of elastic inference accelerators to attach to the instance. </p>\n        <p>Default: 1</p>"
                     }
                 }
@@ -52246,6 +56181,7 @@
         "com.amazonaws.ec2#LaunchTemplateElasticInferenceAcceleratorCount": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1
                 }
@@ -52275,6 +56211,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Count",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p> The number of elastic inference accelerators to attach to the instance. </p>\n        <p>Default: 1</p>",
                         "smithy.api#xmlName": "count"
                     }
@@ -52300,6 +56238,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Enabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If this parameter is set to <code>true</code>, the instance is enabled for Amazon Web Services Nitro\n            Enclaves; otherwise, it is not enabled for Amazon Web Services Nitro Enclaves.</p>",
                         "smithy.api#xmlName": "enabled"
                     }
@@ -52315,6 +56255,8 @@
                 "Enabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>To enable the instance for Amazon Web Services Nitro Enclaves, set this parameter to\n                <code>true</code>.</p>"
                     }
                 }
@@ -52324,34 +56266,44 @@
             }
         },
         "com.amazonaws.ec2#LaunchTemplateErrorCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "launchTemplateIdDoesNotExist",
-                        "name": "LAUNCH_TEMPLATE_ID_DOES_NOT_EXIST"
-                    },
-                    {
-                        "value": "launchTemplateIdMalformed",
-                        "name": "LAUNCH_TEMPLATE_ID_MALFORMED"
-                    },
-                    {
-                        "value": "launchTemplateNameDoesNotExist",
-                        "name": "LAUNCH_TEMPLATE_NAME_DOES_NOT_EXIST"
-                    },
-                    {
-                        "value": "launchTemplateNameMalformed",
-                        "name": "LAUNCH_TEMPLATE_NAME_MALFORMED"
-                    },
-                    {
-                        "value": "launchTemplateVersionDoesNotExist",
-                        "name": "LAUNCH_TEMPLATE_VERSION_DOES_NOT_EXIST"
-                    },
-                    {
-                        "value": "unexpectedError",
-                        "name": "UNEXPECTED_ERROR"
+            "type": "enum",
+            "members": {
+                "LAUNCH_TEMPLATE_ID_DOES_NOT_EXIST": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launchTemplateIdDoesNotExist"
                     }
-                ]
+                },
+                "LAUNCH_TEMPLATE_ID_MALFORMED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launchTemplateIdMalformed"
+                    }
+                },
+                "LAUNCH_TEMPLATE_NAME_DOES_NOT_EXIST": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launchTemplateNameDoesNotExist"
+                    }
+                },
+                "LAUNCH_TEMPLATE_NAME_MALFORMED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launchTemplateNameMalformed"
+                    }
+                },
+                "LAUNCH_TEMPLATE_VERSION_DOES_NOT_EXIST": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launchTemplateVersionDoesNotExist"
+                    }
+                },
+                "UNEXPECTED_ERROR": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unexpectedError"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LaunchTemplateHibernationOptions": {
@@ -52361,6 +56313,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Configured",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If this parameter is set to <code>true</code>, the instance is enabled for\n            hibernation; otherwise, it is not enabled for hibernation.</p>",
                         "smithy.api#xmlName": "configured"
                     }
@@ -52376,6 +56330,8 @@
                 "Configured": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If you set this parameter to <code>true</code>, the instance is enabled for\n            hibernation.</p>\n        <p>Default: <code>false</code>\n         </p>"
                     }
                 }
@@ -52385,18 +56341,20 @@
             }
         },
         "com.amazonaws.ec2#LaunchTemplateHttpTokensState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "optional",
-                        "name": "optional"
-                    },
-                    {
-                        "value": "required",
-                        "name": "required"
+            "type": "enum",
+            "members": {
+                "optional": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "optional"
                     }
-                ]
+                },
+                "required": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "required"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LaunchTemplateIamInstanceProfileSpecification": {
@@ -52530,18 +56488,20 @@
             }
         },
         "com.amazonaws.ec2#LaunchTemplateInstanceMetadataEndpointState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
-                    },
-                    {
-                        "value": "enabled",
-                        "name": "enabled"
+            "type": "enum",
+            "members": {
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
                     }
-                ]
+                },
+                "enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LaunchTemplateInstanceMetadataOptions": {
@@ -52567,6 +56527,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "HttpPutResponseHopLimit",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The desired HTTP PUT response hop limit for instance metadata requests. The larger the\n            number, the further instance metadata requests can travel.</p>\n        <p>Default: 1</p>\n        <p>Possible values: Integers from 1 to 64</p>",
                         "smithy.api#xmlName": "httpPutResponseHopLimit"
                     }
@@ -52612,6 +56574,8 @@
                 "HttpPutResponseHopLimit": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The desired HTTP PUT response hop limit for instance metadata requests. The larger the\n            number, the further instance metadata requests can travel.</p>\n        <p>Default: <code>1</code>\n         </p>\n        <p>Possible values: Integers from 1 to 64</p>"
                     }
                 },
@@ -52639,48 +56603,54 @@
             }
         },
         "com.amazonaws.ec2#LaunchTemplateInstanceMetadataOptionsState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "applied",
-                        "name": "applied"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "applied": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "applied"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LaunchTemplateInstanceMetadataProtocolIpv6": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
-                    },
-                    {
-                        "value": "enabled",
-                        "name": "enabled"
+            "type": "enum",
+            "members": {
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
                     }
-                ]
+                },
+                "enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LaunchTemplateInstanceMetadataTagsState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
-                    },
-                    {
-                        "value": "enabled",
-                        "name": "enabled"
+            "type": "enum",
+            "members": {
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
                     }
-                ]
+                },
+                "enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LaunchTemplateInstanceNetworkInterfaceSpecification": {
@@ -52690,6 +56660,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AssociateCarrierIpAddress",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to associate a Carrier IP address with eth0 for a new network\n            interface.</p>\n        <p>Use this option when you launch an instance in a Wavelength Zone and want to associate\n            a Carrier IP address with the network interface. For more information about Carrier IP\n            addresses, see <a href=\"https://docs.aws.amazon.com/wavelength/latest/developerguide/how-wavelengths-work.html#provider-owned-ip\">Carrier IP addresses</a> in the <i>Wavelength Developer\n            Guide</i>.</p>",
                         "smithy.api#xmlName": "associateCarrierIpAddress"
                     }
@@ -52698,6 +56670,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AssociatePublicIpAddress",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to associate a public IPv4 address with eth0 for a new network\n            interface.</p>",
                         "smithy.api#xmlName": "associatePublicIpAddress"
                     }
@@ -52706,6 +56680,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeleteOnTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the network interface is deleted when the instance is\n            terminated.</p>",
                         "smithy.api#xmlName": "deleteOnTermination"
                     }
@@ -52722,6 +56698,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeviceIndex",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The device index for the network interface attachment.</p>",
                         "smithy.api#xmlName": "deviceIndex"
                     }
@@ -52746,6 +56724,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Ipv6AddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv6 addresses for the network interface.</p>",
                         "smithy.api#xmlName": "ipv6AddressCount"
                     }
@@ -52786,6 +56766,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SecondaryPrivateIpAddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of secondary private IPv4 addresses for the network interface.</p>",
                         "smithy.api#xmlName": "secondaryPrivateIpAddressCount"
                     }
@@ -52802,6 +56784,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkCardIndex",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The index of the network card.</p>",
                         "smithy.api#xmlName": "networkCardIndex"
                     }
@@ -52818,6 +56802,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Ipv4PrefixCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv4 prefixes that Amazon Web Services automatically assigned to the network\n            interface.</p>",
                         "smithy.api#xmlName": "ipv4PrefixCount"
                     }
@@ -52834,6 +56820,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Ipv6PrefixCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv6 prefixes that Amazon Web Services automatically assigned to the network\n            interface.</p>",
                         "smithy.api#xmlName": "ipv6PrefixCount"
                     }
@@ -52858,18 +56846,24 @@
                 "AssociateCarrierIpAddress": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Associates a Carrier IP address with eth0 for a new network interface.</p>\n        <p>Use this option when you launch an instance in a Wavelength Zone and want to associate\n            a Carrier IP address with the network interface. For more information about Carrier IP\n            addresses, see <a href=\"https://docs.aws.amazon.com/wavelength/latest/developerguide/how-wavelengths-work.html#provider-owned-ip\">Carrier IP addresses</a> in the <i>Wavelength Developer\n            Guide</i>.</p>"
                     }
                 },
                 "AssociatePublicIpAddress": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Associates a public IPv4 address with eth0 for a new network interface.</p>"
                     }
                 },
                 "DeleteOnTermination": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the network interface is deleted when the instance is\n            terminated.</p>"
                     }
                 },
@@ -52882,6 +56876,8 @@
                 "DeviceIndex": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The device index for the network interface attachment.</p>"
                     }
                 },
@@ -52901,6 +56897,8 @@
                 "Ipv6AddressCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv6 addresses to assign to a network interface. Amazon EC2\n            automatically selects the IPv6 addresses from the subnet range. You can't use this\n            option if specifying specific IPv6 addresses.</p>"
                     }
                 },
@@ -52931,6 +56929,8 @@
                 "SecondaryPrivateIpAddressCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of secondary private IPv4 addresses to assign to a network\n            interface.</p>"
                     }
                 },
@@ -52943,6 +56943,8 @@
                 "NetworkCardIndex": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The index of the network card. Some instance types support multiple network cards. The\n            primary network interface must be assigned to network card index 0. The default is\n            network card index 0.</p>"
                     }
                 },
@@ -52956,6 +56958,8 @@
                 "Ipv4PrefixCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv4 prefixes to be automatically assigned to the network interface. You\n            cannot use this option if you use the <code>Ipv4Prefix</code> option.</p>"
                     }
                 },
@@ -52969,6 +56973,8 @@
                 "Ipv6PrefixCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv6 prefixes to be automatically assigned to the network interface. You\n            cannot use this option if you use the <code>Ipv6Prefix</code> option.</p>"
                     }
                 }
@@ -53092,6 +57098,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "WeightedCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of units provided by the specified instance type.</p>",
                         "smithy.api#xmlName": "weightedCapacity"
                     }
@@ -53100,6 +57108,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Priority",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The priority for the launch template override. The highest priority is launched\n            first.</p>\n        <p>If <code>OnDemandAllocationStrategy</code> is set to <code>prioritized</code>, Spot Fleet\n            uses priority to determine which launch template override to use first in fulfilling\n            On-Demand capacity.</p>\n        <p>If the Spot <code>AllocationStrategy</code> is set to\n                <code>capacityOptimizedPrioritized</code>, Spot Fleet uses priority on a best-effort basis\n            to determine which launch template override to use in fulfilling Spot capacity, but\n            optimizes for capacity first.</p>\n        <p>Valid values are whole numbers starting at <code>0</code>. The lower the number, the\n            higher the priority. If no number is set, the launch template override has the lowest\n            priority. You can set the same priority for different launch template overrides.</p>",
                         "smithy.api#xmlName": "priority"
                     }
@@ -53189,6 +57199,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PartitionNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of the partition the instance should launch in. Valid only if the placement\n            group strategy is set to <code>partition</code>.</p>",
                         "smithy.api#xmlName": "partitionNumber"
                     }
@@ -53246,6 +57258,8 @@
                 "PartitionNumber": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of the partition the instance should launch in. Valid only if the placement\n            group strategy is set to <code>partition</code>.</p>"
                     }
                 }
@@ -53269,6 +57283,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnableResourceNameDnsARecord",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostnames with DNS A\n            records.</p>",
                         "smithy.api#xmlName": "enableResourceNameDnsARecord"
                     }
@@ -53277,6 +57293,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnableResourceNameDnsAAAARecord",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostnames with DNS AAAA\n            records.</p>",
                         "smithy.api#xmlName": "enableResourceNameDnsAAAARecord"
                     }
@@ -53298,12 +57316,16 @@
                 "EnableResourceNameDnsARecord": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostnames with DNS A\n            records.</p>"
                     }
                 },
                 "EnableResourceNameDnsAAAARecord": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostnames with DNS AAAA\n            records.</p>"
                     }
                 }
@@ -53370,6 +57392,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "BlockDurationMinutes",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The required duration for the Spot Instances (also known as Spot blocks), in minutes.\n            This value must be a multiple of 60 (60, 120, 180, 240, 300, or 360).</p>",
                         "smithy.api#xmlName": "blockDurationMinutes"
                     }
@@ -53413,6 +57437,8 @@
                 "BlockDurationMinutes": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>Deprecated.</p>"
                     }
                 },
@@ -53519,6 +57545,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VersionNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The version number.</p>",
                         "smithy.api#xmlName": "versionNumber"
                     }
@@ -53551,6 +57579,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DefaultVersion",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the version is the default version.</p>",
                         "smithy.api#xmlName": "defaultVersion"
                     }
@@ -53584,6 +57614,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Enabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether detailed monitoring is enabled. Otherwise, basic monitoring is\n            enabled.</p>",
                         "smithy.api#xmlName": "enabled"
                     }
@@ -53599,6 +57631,8 @@
                 "Enabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specify <code>true</code> to enable detailed monitoring. Otherwise, basic monitoring\n            is enabled.</p>"
                     }
                 }
@@ -53676,7 +57710,6 @@
         "com.amazonaws.ec2#ListImagesInRecycleBinMaxResults": {
             "type": "integer",
             "traits": {
-                "smithy.api#box": {},
                 "smithy.api#range": {
                     "min": 1,
                     "max": 1000
@@ -53708,6 +57741,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -53755,7 +57790,6 @@
         "com.amazonaws.ec2#ListSnapshotsInRecycleBinMaxResults": {
             "type": "integer",
             "traits": {
-                "smithy.api#box": {},
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -53787,6 +57821,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -53814,49 +57850,61 @@
             }
         },
         "com.amazonaws.ec2#ListingState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "sold",
-                        "name": "sold"
-                    },
-                    {
-                        "value": "cancelled",
-                        "name": "cancelled"
-                    },
-                    {
-                        "value": "pending",
-                        "name": "pending"
+            "type": "enum",
+            "members": {
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
                     }
-                ]
+                },
+                "sold": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "sold"
+                    }
+                },
+                "cancelled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelled"
+                    }
+                },
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ListingStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "cancelled",
-                        "name": "cancelled"
-                    },
-                    {
-                        "value": "closed",
-                        "name": "closed"
+            "type": "enum",
+            "members": {
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
                     }
-                ]
+                },
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
+                    }
+                },
+                "cancelled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelled"
+                    }
+                },
+                "closed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "closed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LoadBalancersConfig": {
@@ -54028,6 +58076,7 @@
         "com.amazonaws.ec2#LocalGatewayMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -54132,30 +58181,38 @@
             }
         },
         "com.amazonaws.ec2#LocalGatewayRouteState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "blackhole",
-                        "name": "blackhole"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "blackhole": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "blackhole"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LocalGatewayRouteTable": {
@@ -54247,18 +58304,20 @@
             }
         },
         "com.amazonaws.ec2#LocalGatewayRouteTableMode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "direct-vpc-routing",
-                        "name": "direct_vpc_routing"
-                    },
-                    {
-                        "value": "coip",
-                        "name": "coip"
+            "type": "enum",
+            "members": {
+                "direct_vpc_routing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "direct-vpc-routing"
                     }
-                ]
+                },
+                "coip": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "coip"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LocalGatewayRouteTableSet": {
@@ -54457,18 +58516,20 @@
             }
         },
         "com.amazonaws.ec2#LocalGatewayRouteType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "static",
-                        "name": "static"
-                    },
-                    {
-                        "value": "propagated",
-                        "name": "propagated"
+            "type": "enum",
+            "members": {
+                "static": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "static"
                     }
-                ]
+                },
+                "propagated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "propagated"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LocalGatewayRoutetableId": {
@@ -54506,6 +58567,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Vlan",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The ID of the VLAN.</p>",
                         "smithy.api#xmlName": "vlan"
                     }
@@ -54530,6 +58593,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "LocalBgpAsn",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The Border Gateway Protocol (BGP) Autonomous System Number (ASN) of the local gateway.</p>",
                         "smithy.api#xmlName": "localBgpAsn"
                     }
@@ -54538,6 +58603,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PeerBgpAsn",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The peer BGP ASN.</p>",
                         "smithy.api#xmlName": "peerBgpAsn"
                     }
@@ -54654,37 +58721,43 @@
             }
         },
         "com.amazonaws.ec2#LocalStorage": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "included",
-                        "name": "INCLUDED"
-                    },
-                    {
-                        "value": "required",
-                        "name": "REQUIRED"
-                    },
-                    {
-                        "value": "excluded",
-                        "name": "EXCLUDED"
+            "type": "enum",
+            "members": {
+                "INCLUDED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "included"
                     }
-                ]
+                },
+                "REQUIRED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "required"
+                    }
+                },
+                "EXCLUDED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "excluded"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LocalStorageType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "hdd",
-                        "name": "HDD"
-                    },
-                    {
-                        "value": "ssd",
-                        "name": "SSD"
+            "type": "enum",
+            "members": {
+                "HDD": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "hdd"
                     }
-                ]
+                },
+                "SSD": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ssd"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LocalStorageTypeSet": {
@@ -54700,45 +58773,56 @@
             "type": "string"
         },
         "com.amazonaws.ec2#LocationType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "region",
-                        "name": "region"
-                    },
-                    {
-                        "value": "availability-zone",
-                        "name": "availability_zone"
-                    },
-                    {
-                        "value": "availability-zone-id",
-                        "name": "availability_zone_id"
+            "type": "enum",
+            "members": {
+                "region": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "region"
                     }
-                ]
+                },
+                "availability_zone": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "availability-zone"
+                    }
+                },
+                "availability_zone_id": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "availability-zone-id"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#LogDestinationType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "cloud-watch-logs",
-                        "name": "cloud_watch_logs"
-                    },
-                    {
-                        "value": "s3",
-                        "name": "s3"
-                    },
-                    {
-                        "value": "kinesis-data-firehose",
-                        "name": "kinesis_data_firehose"
+            "type": "enum",
+            "members": {
+                "cloud_watch_logs": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cloud-watch-logs"
                     }
-                ]
+                },
+                "s3": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "s3"
+                    }
+                },
+                "kinesis_data_firehose": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "kinesis-data-firehose"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#Long": {
-            "type": "long"
+            "type": "long",
+            "traits": {
+                "smithy.api#default": 0
+            }
         },
         "com.amazonaws.ec2#ManagedPrefixList": {
             "type": "structure",
@@ -54795,6 +58879,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxEntries",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of entries for the prefix list.</p>",
                         "smithy.api#xmlName": "maxEntries"
                     }
@@ -54803,6 +58889,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Version",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The version of the prefix list.</p>",
                         "smithy.api#xmlName": "version"
                     }
@@ -54838,83 +58926,58 @@
             }
         },
         "com.amazonaws.ec2#MarketType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "spot",
-                        "name": "spot"
+            "type": "enum",
+            "members": {
+                "spot": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "spot"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#MaxIpv4AddrPerInterface": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#MaxIpv6AddrPerInterface": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#MaxNetworkInterfaces": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#MaxResults": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#MaximumBandwidthInMbps": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#MaximumEfaInterfaces": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#MaximumIops": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#MaximumNetworkCards": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#MaximumThroughputInMBps": {
-            "type": "double",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "double"
         },
         "com.amazonaws.ec2#MembershipType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "static",
-                        "name": "static"
-                    },
-                    {
-                        "value": "igmp",
-                        "name": "igmp"
+            "type": "enum",
+            "members": {
+                "static": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "static"
                     }
-                ]
+                },
+                "igmp": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "igmp"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#MemoryGiBPerVCpu": {
@@ -54924,6 +58987,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Min",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum amount of memory per vCPU, in GiB. If this parameter is not specified, there is\n         no minimum limit.</p>",
                         "smithy.api#xmlName": "min"
                     }
@@ -54932,6 +58997,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Max",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum amount of memory per vCPU, in GiB. If this parameter is not specified, there is\n         no maximum limit.</p>",
                         "smithy.api#xmlName": "max"
                     }
@@ -54947,12 +59014,16 @@
                 "Min": {
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum amount of memory per vCPU, in GiB. To specify no minimum limit, omit this\n         parameter.</p>"
                     }
                 },
                 "Max": {
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum amount of memory per vCPU, in GiB. To specify no maximum limit, omit this\n         parameter.</p>"
                     }
                 }
@@ -54984,6 +59055,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Min",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum amount of memory, in MiB. If this parameter is not specified, there is no minimum\n         limit.</p>",
                         "smithy.api#xmlName": "min"
                     }
@@ -54992,6 +59065,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Max",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum amount of memory, in MiB. If this parameter is not specified, there is no\n         maximum limit.</p>",
                         "smithy.api#xmlName": "max"
                     }
@@ -55007,6 +59082,8 @@
                 "Min": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum amount of memory, in MiB. To specify no minimum limit, specify\n         <code>0</code>.</p>",
                         "smithy.api#required": {}
                     }
@@ -55014,6 +59091,8 @@
                 "Max": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum amount of memory, in MiB. To specify no maximum limit, omit this\n         parameter.</p>"
                     }
                 }
@@ -55023,10 +59102,7 @@
             }
         },
         "com.amazonaws.ec2#MemorySize": {
-            "type": "long",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "long"
         },
         "com.amazonaws.ec2#MillisecondDateTime": {
             "type": "timestamp"
@@ -55049,6 +59125,7 @@
                 "AllocationId": {
                     "target": "com.amazonaws.ec2#AllocationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>[EC2-VPC] The allocation ID.</p>",
                         "smithy.api#required": {}
                     }
@@ -55062,6 +59139,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -55098,6 +59177,7 @@
                 "GroupName": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The name of the Availability Zone group, Local Zone group, or Wavelength Zone\n      group.</p>",
                         "smithy.api#required": {}
                     }
@@ -55105,6 +59185,7 @@
                 "OptInStatus": {
                     "target": "com.amazonaws.ec2#ModifyAvailabilityZoneOptInStatus",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Indicates whether you are opted in to the Local Zone group or Wavelength Zone group. The\n      only valid value is <code>opted-in</code>. You must contact <a href=\"https://console.aws.amazon.com/support/home#/case/create%3FissueType=customer-service%26serviceCode=general-info%26getting-started%26categoryCode=using-aws%26services\">Amazon Web Services Support</a> to opt out of a Local Zone or Wavelength Zone group.</p>",
                         "smithy.api#required": {}
                     }
@@ -55112,6 +59193,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -55124,6 +59207,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Is <code>true</code> if the request succeeds, and an error otherwise.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -55131,18 +59216,20 @@
             }
         },
         "com.amazonaws.ec2#ModifyAvailabilityZoneOptInStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "opted-in",
-                        "name": "opted_in"
-                    },
-                    {
-                        "value": "not-opted-in",
-                        "name": "not_opted_in"
+            "type": "enum",
+            "members": {
+                "opted_in": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "opted-in"
                     }
-                ]
+                },
+                "not_opted_in": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "not-opted-in"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ModifyCapacityReservation": {
@@ -55175,6 +59262,7 @@
                 "CapacityReservationFleetId": {
                     "target": "com.amazonaws.ec2#CapacityReservationFleetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Capacity Reservation Fleet to modify.</p>",
                         "smithy.api#required": {}
                     }
@@ -55182,6 +59270,8 @@
                 "TotalTargetCapacity": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of capacity units to be reserved by the Capacity Reservation Fleet. This value, \n\t\t\ttogether with the instance type weights that you assign to each instance type used by the Fleet \n\t\t\tdetermine the number of instances for which the Fleet reserves capacity. Both values are based on \n\t\t\tunits that make sense for your workload. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/crfleet-concepts.html#target-capacity\">Total target capacity</a> \n\t\t\tin the Amazon EC2 User Guide.</p>"
                     }
                 },
@@ -55194,12 +59284,16 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "RemoveEndDate": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to remove the end date from the Capacity Reservation Fleet. If you remove the \n\t\t\tend date, the Capacity Reservation Fleet does not expire and it remains active until you explicitly \n\t\t\tcancel it using the <b>CancelCapacityReservationFleet</b> action.</p>\n\t\t       <p>You can't specify <b>RemoveEndDate</b> and <b>\n\t\t\tEndDate</b> in the same request.</p>"
                     }
                 }
@@ -55212,6 +59306,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -55224,6 +59320,7 @@
                 "CapacityReservationId": {
                     "target": "com.amazonaws.ec2#CapacityReservationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Capacity Reservation.</p>",
                         "smithy.api#required": {}
                     }
@@ -55231,6 +59328,8 @@
                 "InstanceCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of instances for which to reserve capacity. The number of instances can't be increased or \n\t\t    \tdecreased by more than <code>1000</code> in a single request.</p>"
                     }
                 },
@@ -55249,12 +59348,16 @@
                 "Accept": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Reserved. Capacity Reservations you have created are accepted by default.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -55273,6 +59376,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -55297,6 +59402,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint to modify.</p>",
                         "smithy.api#required": {}
                     }
@@ -55322,6 +59428,8 @@
                 "VpnPort": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The port number to assign to the Client VPN endpoint for TCP and UDP traffic.</p>\n\t        <p>Valid Values: <code>443</code> | <code>1194</code>\n         </p>\n\t        <p>Default Value: <code>443</code>\n         </p>"
                     }
                 },
@@ -55334,12 +59442,16 @@
                 "SplitTunnel": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the VPN is split-tunnel.</p>\n        <p>For information about split-tunnel VPN endpoints, see <a href=\"https://docs.aws.amazon.com/vpn/latest/clientvpn-admin/split-tunnel-vpn.html\">Split-tunnel Client VPN endpoint</a> in the \n        \t<i>Client VPN Administrator Guide</i>.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -55371,6 +59483,8 @@
                 "SessionTimeoutHours": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum VPN session duration time in hours.</p>\n\t\t       <p>Valid values: <code>8 | 10 | 12 | 24</code>\n         </p>\n\t\t       <p>Default value: <code>24</code>\n         </p>"
                     }
                 },
@@ -55389,6 +59503,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -55413,12 +59529,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "InstanceFamily": {
                     "target": "com.amazonaws.ec2#UnlimitedSupportedInstanceFamily",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The instance family.</p>",
                         "smithy.api#required": {}
                     }
@@ -55426,6 +59545,7 @@
                 "CpuCredits": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The credit option for CPU usage of the instance family.</p>\n        <p>Valid Values: <code>standard</code> | <code>unlimited</code>\n         </p>",
                         "smithy.api#required": {}
                     }
@@ -55463,6 +59583,7 @@
                 "KmsKeyId": {
                     "target": "com.amazonaws.ec2#KmsKeyId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The identifier of the Key Management Service (KMS) KMS key to use for Amazon EBS encryption.\n      If this parameter is not specified, your KMS key for Amazon EBS is used. If <code>KmsKeyId</code> is\n      specified, the encrypted state must be <code>true</code>.</p>\n         <p>You can specify the KMS key using any of the following:</p>\n         <ul>\n            <li>\n               <p>Key ID. For example, 1234abcd-12ab-34cd-56ef-1234567890ab.</p>\n            </li>\n            <li>\n               <p>Key alias. For example, alias/ExampleAlias.</p>\n            </li>\n            <li>\n               <p>Key ARN. For example, arn:aws:kms:us-east-1:012345678910:key/1234abcd-12ab-34cd-56ef-1234567890ab.</p>\n            </li>\n            <li>\n               <p>Alias ARN. For example, arn:aws:kms:us-east-1:012345678910:alias/ExampleAlias.</p>\n            </li>\n         </ul>\n         <p>Amazon Web Services authenticates the KMS key asynchronously. Therefore, if you specify an ID, alias, or ARN that is not valid, \n      the action can appear to complete, but eventually fails.</p>  \n         <p>Amazon EBS does not support asymmetric KMS keys.</p>",
                         "smithy.api#required": {}
                     }
@@ -55470,6 +59591,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -55506,6 +59629,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -55525,6 +59650,7 @@
                 "FleetId": {
                     "target": "com.amazonaws.ec2#FleetId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the EC2 Fleet.</p>",
                         "smithy.api#required": {}
                     }
@@ -55550,6 +59676,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If the request succeeds, the response returns <code>true</code>. If the request fails,\n         no response is returned, and instead an error message is returned.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -55574,12 +59702,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "FpgaImageId": {
                     "target": "com.amazonaws.ec2#FpgaImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AFI.</p>",
                         "smithy.api#required": {}
                     }
@@ -55677,6 +59808,7 @@
                     "target": "com.amazonaws.ec2#RequestHostIdList",
                     "traits": {
                         "aws.protocols#ec2QueryName": "HostId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the Dedicated Hosts to modify.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "hostId"
@@ -55741,6 +59873,7 @@
                 "Resource": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The type of resource: <code>bundle</code> | <code>conversion-task</code> | <code>customer-gateway</code> | <code>dhcp-options</code> |\n           <code>elastic-ip-allocation</code> | <code>elastic-ip-association</code> |\n           <code>export-task</code> | <code>flow-log</code> | <code>image</code> |\n           <code>import-task</code> | <code>internet-gateway</code> | <code>network-acl</code>\n           | <code>network-acl-association</code> | <code>network-interface</code> |\n           <code>network-interface-attachment</code> | <code>prefix-list</code> |\n           <code>route-table</code> | <code>route-table-association</code> |\n           <code>security-group</code> | <code>subnet</code> |\n           <code>subnet-cidr-block-association</code> | <code>vpc</code> |\n           <code>vpc-cidr-block-association</code> | <code>vpc-endpoint</code> | <code>vpc-peering-connection</code> | <code>vpn-connection</code> | <code>vpn-gateway</code>.</p>\n         <p>Alternatively, use the <code>all-current</code> option to include all resource types that are\n       currently within their opt-in period for longer IDs.</p>",
                         "smithy.api#required": {}
                     }
@@ -55748,6 +59881,8 @@
                 "UseLongIds": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicate whether the resource should use longer IDs (17-character IDs).</p>",
                         "smithy.api#required": {}
                     }
@@ -55773,6 +59908,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PrincipalArn",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ARN of the principal, which can be an IAM user, IAM role, or the root user. Specify\n       <code>all</code> to modify the ID format for all IAM users, IAM roles, and the root user of\n       the account.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "principalArn"
@@ -55782,6 +59918,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Resource",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The type of resource: <code>bundle</code> | <code>conversion-task</code> | <code>customer-gateway</code> | <code>dhcp-options</code> |\n          <code>elastic-ip-allocation</code> | <code>elastic-ip-association</code> |\n          <code>export-task</code> | <code>flow-log</code> | <code>image</code> |\n          <code>import-task</code> | <code>internet-gateway</code> | <code>network-acl</code>\n          | <code>network-acl-association</code> | <code>network-interface</code> |\n          <code>network-interface-attachment</code> | <code>prefix-list</code> |\n          <code>route-table</code> | <code>route-table-association</code> |\n          <code>security-group</code> | <code>subnet</code> |\n          <code>subnet-cidr-block-association</code> | <code>vpc</code> |\n          <code>vpc-cidr-block-association</code> | <code>vpc-endpoint</code> | <code>vpc-peering-connection</code> | <code>vpn-connection</code> | <code>vpn-gateway</code>.</p>\n         <p>Alternatively, use the <code>all-current</code> option to include all resource types that are\n          currently within their opt-in period for longer IDs.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "resource"
@@ -55791,6 +59928,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "UseLongIds",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the resource should use longer IDs (17-character IDs)</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "useLongIds"
@@ -55828,6 +59967,7 @@
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AMI.</p>",
                         "smithy.api#required": {}
                     }
@@ -55875,6 +60015,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -55947,6 +60089,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -55978,6 +60122,7 @@
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "instanceId"
@@ -56065,6 +60210,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance to be modified.</p>",
                         "smithy.api#required": {}
                     }
@@ -56072,6 +60218,7 @@
                 "CapacityReservationSpecification": {
                     "target": "com.amazonaws.ec2#CapacityReservationSpecification",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Information about the Capacity Reservation targeting option.</p>",
                         "smithy.api#required": {}
                     }
@@ -56079,6 +60226,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -56091,6 +60240,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -56115,6 +60266,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -56127,6 +60280,7 @@
                 "InstanceCreditSpecifications": {
                     "target": "com.amazonaws.ec2#InstanceCreditSpecificationListRequest",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Information about the credit option for CPU usage.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "InstanceCreditSpecification"
@@ -56173,12 +60327,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance with the scheduled event.</p>",
                         "smithy.api#required": {}
                     }
@@ -56186,6 +60343,7 @@
                 "InstanceEventId": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the event whose date and time you are modifying.</p>",
                         "smithy.api#required": {}
                     }
@@ -56193,6 +60351,7 @@
                 "NotBefore": {
                     "target": "com.amazonaws.ec2#DateTime",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The new date and time when the event will take place.</p>",
                         "smithy.api#required": {}
                     }
@@ -56229,6 +60388,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -56241,6 +60402,7 @@
                 "InstanceEventWindowId": {
                     "target": "com.amazonaws.ec2#InstanceEventWindowId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the event window.</p>",
                         "smithy.api#required": {}
                     }
@@ -56291,6 +60453,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {}
                     }
@@ -56304,6 +60467,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -56348,6 +60513,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {}
                     }
@@ -56361,6 +60527,8 @@
                 "HttpPutResponseHopLimit": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The desired HTTP PUT response hop limit for instance metadata requests. The larger the\n            number, the further instance metadata requests can travel. If no parameter is specified,\n            the existing state is maintained.</p>\n        <p>Possible values: Integers from 1 to 64</p>"
                     }
                 },
@@ -56373,6 +60541,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -56452,6 +60622,7 @@
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance that you are modifying.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "instanceId"
@@ -56468,6 +60639,8 @@
                 "PartitionNumber": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of the partition in which to place the instance. Valid only if the\n            placement group strategy is set to <code>partition</code>.</p>"
                     }
                 },
@@ -56486,6 +60659,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Is <code>true</code> if the request succeeds, and an error otherwise.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -56522,12 +60697,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamPoolId": {
                     "target": "com.amazonaws.ec2#IpamPoolId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPAM pool you want to modify.</p>",
                         "smithy.api#required": {}
                     }
@@ -56541,30 +60719,40 @@
                 "AutoImport": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If true, IPAM will continuously look for resources within the CIDR range of this pool \n         and automatically import them as allocations into your IPAM. The CIDRs that will be allocated for\n         these resources must not already be allocated to other resources in order for the import to succeed. IPAM will import \n         a CIDR regardless of its compliance with the pool's allocation rules, so a resource might be imported and subsequently \n         marked as noncompliant. If IPAM discovers multiple CIDRs that overlap, IPAM will import the largest CIDR only. If IPAM \n         discovers multiple CIDRs with matching CIDRs, IPAM will randomly import one of them only.\n      </p>\n         <p>A locale must be set on the pool for this feature to work.</p>"
                     }
                 },
                 "AllocationMinNetmaskLength": {
                     "target": "com.amazonaws.ec2#IpamNetmaskLength",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum netmask length required for CIDR allocations in this IPAM pool to be compliant. Possible \n         netmask lengths for IPv4 addresses are 0 - 32. Possible netmask lengths for IPv6 addresses are  0 - 128. The minimum netmask \n         length must be less than the maximum netmask length.</p>"
                     }
                 },
                 "AllocationMaxNetmaskLength": {
                     "target": "com.amazonaws.ec2#IpamNetmaskLength",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum netmask length possible for CIDR allocations in this IPAM pool to be compliant. Possible \n         netmask lengths for IPv4 addresses are 0 - 32. Possible netmask lengths for IPv6 addresses are  0 - 128.The maximum netmask \n         length must be greater than the minimum netmask length.</p>"
                     }
                 },
                 "AllocationDefaultNetmaskLength": {
                     "target": "com.amazonaws.ec2#IpamNetmaskLength",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The default netmask length for allocations added to this pool. If, for example, the CIDR assigned to this pool is 10.0.0.0/8 and you enter 16 here, new allocations will default to 10.0.0.0/16.</p>"
                     }
                 },
                 "ClearAllocationDefaultNetmaskLength": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Clear the default netmask length allocation rule for this pool.</p>"
                     }
                 },
@@ -56603,12 +60791,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamId": {
                     "target": "com.amazonaws.ec2#IpamId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPAM you want to modify.</p>",
                         "smithy.api#required": {}
                     }
@@ -56653,12 +60844,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ResourceId": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the resource you want to modify.</p>",
                         "smithy.api#required": {}
                     }
@@ -56666,6 +60860,7 @@
                 "ResourceCidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR of the resource you want to modify.</p>",
                         "smithy.api#required": {}
                     }
@@ -56673,6 +60868,7 @@
                 "ResourceRegion": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Amazon Web Services Region of the resource you want to modify.</p>",
                         "smithy.api#required": {}
                     }
@@ -56680,6 +60876,7 @@
                 "CurrentIpamScopeId": {
                     "target": "com.amazonaws.ec2#IpamScopeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the current scope that the resource CIDR is in.</p>",
                         "smithy.api#required": {}
                     }
@@ -56693,6 +60890,8 @@
                 "Monitored": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Determines if the resource is monitored by IPAM. If a resource is monitored, the resource is discovered by IPAM and you can view details about the resource’s CIDR.</p>",
                         "smithy.api#required": {}
                     }
@@ -56742,12 +60941,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamScopeId": {
                     "target": "com.amazonaws.ec2#IpamScopeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the scope you want to modify.</p>",
                         "smithy.api#required": {}
                     }
@@ -56791,6 +60993,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -56852,6 +61056,7 @@
                 "DestinationCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR block used for destination matches. The value that you provide must match the CIDR of an existing route in the table.</p>",
                         "smithy.api#required": {}
                     }
@@ -56859,6 +61064,7 @@
                 "LocalGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#LocalGatewayRoutetableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the local gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -56878,6 +61084,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -56913,12 +61121,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "PrefixListId": {
                     "target": "com.amazonaws.ec2#PrefixListResourceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the prefix list.</p>",
                         "smithy.api#required": {}
                     }
@@ -56926,6 +61137,8 @@
                 "CurrentVersion": {
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The current version of the prefix list.</p>"
                     }
                 },
@@ -56952,6 +61165,8 @@
                 "MaxEntries": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of entries for the prefix list. You cannot modify the entries  \n            of a prefix list and modify the size of a prefix list at the same time.</p>\n        <p>If any of the resources that reference the prefix list cannot support the new\n            maximum size, the modify operation fails. Check the state message for the IDs of \n            the first ten resources that do not support the new maximum size.</p>"
                     }
                 }
@@ -57005,6 +61220,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n            and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n            Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -57020,6 +61237,7 @@
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkInterfaceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network interface.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkInterfaceId"
@@ -57056,6 +61274,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -57074,12 +61294,16 @@
                 "EnableResourceNameDnsARecord": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostnames with DNS A\n            records.</p>"
                     }
                 },
                 "EnableResourceNameDnsAAAARecord": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostnames with DNS AAAA\n            records.</p>"
                     }
                 }
@@ -57092,6 +61316,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an\n            error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -57116,6 +61342,7 @@
                 "ReservedInstancesIds": {
                     "target": "com.amazonaws.ec2#ReservedInstancesIdStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the Reserved Instances to modify.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ReservedInstancesId"
@@ -57132,6 +61359,7 @@
                 "TargetConfigurations": {
                     "target": "com.amazonaws.ec2#ReservedInstancesConfigurationList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The configuration settings for the Reserved Instances to modify.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ReservedInstancesConfigurationSetItemType"
@@ -57176,6 +61404,7 @@
                 "GroupId": {
                     "target": "com.amazonaws.ec2#SecurityGroupId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the security group.</p>",
                         "smithy.api#required": {}
                     }
@@ -57183,6 +61412,7 @@
                 "SecurityGroupRules": {
                     "target": "com.amazonaws.ec2#SecurityGroupRuleUpdateList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Information about the security group properties to update.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "SecurityGroupRule"
@@ -57191,6 +61421,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -57203,6 +61435,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -57252,6 +61486,7 @@
                 "SnapshotId": {
                     "target": "com.amazonaws.ec2#SnapshotId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the snapshot.</p>",
                         "smithy.api#required": {}
                     }
@@ -57267,6 +61502,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -57291,6 +61528,7 @@
                 "SnapshotId": {
                     "target": "com.amazonaws.ec2#SnapshotId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the snapshot.</p>",
                         "smithy.api#required": {}
                     }
@@ -57304,6 +61542,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -57364,6 +61604,7 @@
                     "target": "com.amazonaws.ec2#SpotFleetRequestId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SpotFleetRequestId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Spot Fleet request.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "spotFleetRequestId"
@@ -57373,6 +61614,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TargetCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the fleet.</p>",
                         "smithy.api#xmlName": "targetCapacity"
                     }
@@ -57380,6 +61623,8 @@
                 "OnDemandTargetCapacity": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of On-Demand Instances in the fleet.</p>"
                     }
                 },
@@ -57401,6 +61646,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If the request succeeds, the response returns <code>true</code>. If the request fails,\n            no response is returned, and instead an error message is returned.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -57441,6 +61688,7 @@
                     "target": "com.amazonaws.ec2#SubnetId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SubnetId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the subnet.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "subnetId"
@@ -57485,6 +61733,8 @@
                 "EnableLniAtDeviceIndex": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>\n            Indicates the device position for local network interfaces in this subnet. For example, \n            <code>1</code> indicates local network interfaces in this subnet are the secondary \n            network interface (eth1). A local network interface cannot be the primary network\n            interface (eth0).\n        </p>"
                     }
                 },
@@ -57514,6 +61764,7 @@
                 "TrafficMirrorFilterId": {
                     "target": "com.amazonaws.ec2#TrafficMirrorFilterId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Traffic Mirror filter.</p>",
                         "smithy.api#required": {}
                     }
@@ -57535,6 +61786,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -57571,6 +61824,7 @@
                 "TrafficMirrorFilterRuleId": {
                     "target": "com.amazonaws.ec2#TrafficMirrorFilterRuleId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Traffic Mirror rule.</p>",
                         "smithy.api#required": {}
                     }
@@ -57584,6 +61838,8 @@
                 "RuleNumber": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of the Traffic Mirror rule. This number must be unique for each Traffic Mirror rule in a given\n         direction. The rules are processed in ascending order by rule number.</p>"
                     }
                 },
@@ -57608,6 +61864,8 @@
                 "Protocol": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The protocol, for example TCP, to assign to the Traffic Mirror rule.</p>"
                     }
                 },
@@ -57639,6 +61897,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -57675,6 +61935,7 @@
                 "TrafficMirrorSessionId": {
                     "target": "com.amazonaws.ec2#TrafficMirrorSessionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Traffic Mirror session.</p>",
                         "smithy.api#required": {}
                     }
@@ -57694,18 +61955,24 @@
                 "PacketLength": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of bytes in each packet to mirror. These are bytes after the VXLAN header. To mirror a subset, set this to the length (in bytes) to mirror. For example, if you set this value to 100, then the first 100 bytes that meet the filter criteria are copied to the target. Do not specify this parameter when you want to mirror the entire packet.</p>"
                     }
                 },
                 "SessionNumber": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The session number determines the order in which sessions are evaluated when an interface is used by multiple sessions. The first session with a matching filter is the one that mirrors the packets.</p>\n         <p>Valid values are 1-32766.</p>"
                     }
                 },
                 "VirtualNetworkId": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The virtual network ID of the Traffic Mirror session.</p>"
                     }
                 },
@@ -57725,6 +61992,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -57815,6 +62084,8 @@
                 "AmazonSideAsn": {
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>A private Autonomous System Number (ASN) for the Amazon side of a BGP session. \n            The range is 64512 to 65534 for 16-bit ASNs and 4200000000 to 4294967294 for 32-bit ASNs.</p>"
                     }
                 }
@@ -57841,6 +62112,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -57848,6 +62120,7 @@
                 "PrefixListId": {
                     "target": "com.amazonaws.ec2#PrefixListResourceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the prefix list.</p>",
                         "smithy.api#required": {}
                     }
@@ -57861,12 +62134,16 @@
                 "Blackhole": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to drop traffic that matches this route.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -57891,6 +62168,7 @@
                 "TransitGatewayId": {
                     "target": "com.amazonaws.ec2#TransitGatewayId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway.</p>",
                         "smithy.api#required": {}
                     }
@@ -57910,6 +62188,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -57945,6 +62225,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -57970,6 +62251,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -58050,6 +62333,7 @@
                 "VolumeId": {
                     "target": "com.amazonaws.ec2#VolumeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the volume.</p>",
                         "smithy.api#required": {}
                     }
@@ -58058,6 +62342,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -58070,12 +62356,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "VolumeId": {
                     "target": "com.amazonaws.ec2#VolumeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the volume.</p>",
                         "smithy.api#required": {}
                     }
@@ -58083,6 +62372,8 @@
                 "Size": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The target size of the volume, in GiB. The target volume size must be greater than or\n      equal to the existing size of the volume.</p>\n         <p>The following are the supported volumes sizes for each volume type:</p>\n         <ul>\n            <li>\n               <p>\n                  <code>gp2</code> and <code>gp3</code>: 1-16,384</p>\n            </li>\n            <li>\n               <p>\n                  <code>io1</code> and <code>io2</code>: 4-16,384</p>\n            </li>\n            <li>\n               <p>\n                  <code>st1</code> and <code>sc1</code>: 125-16,384</p>\n            </li>\n            <li>\n               <p>\n                  <code>standard</code>: 1-1,024</p>\n            </li>\n         </ul>\n         <p>Default: The existing size is retained.</p>"
                     }
                 },
@@ -58095,18 +62386,24 @@
                 "Iops": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The target IOPS rate of the volume. This parameter is valid only for <code>gp3</code>, <code>io1</code>, and <code>io2</code> volumes.</p>\n         <p>The following are the supported values for each volume type:</p>\n         <ul>\n            <li>\n               <p>\n                  <code>gp3</code>: 3,000-16,000 IOPS</p>\n            </li>\n            <li>\n               <p>\n                  <code>io1</code>: 100-64,000 IOPS</p>\n            </li>\n            <li>\n               <p>\n                  <code>io2</code>: 100-64,000 IOPS</p>\n            </li>\n         </ul>\n         <p>Default: The existing value is retained if you keep the same volume type. If you change\n      the volume type to <code>io1</code>, <code>io2</code>, or <code>gp3</code>, the default is 3,000.</p>"
                     }
                 },
                 "Throughput": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The target throughput of the volume, in MiB/s. This parameter is valid only for <code>gp3</code> volumes. \n      The maximum value is 1,000.</p>\n         <p>Default: The existing value is retained if the source and target volume type is <code>gp3</code>.\n      Otherwise, the default value is 125.</p>\n  \t      <p>Valid Range: Minimum value of 125. Maximum value of 1000.</p>"
                     }
                 },
                 "MultiAttachEnabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specifies whether to enable Amazon EBS Multi-Attach. If you enable Multi-Attach, you can attach the \n\t\tvolume to up to 16 <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html#ec2-nitro-instances\">\n\t\t\tNitro-based instances</a> in the same Availability Zone. This parameter is \n\t\tsupported with <code>io1</code> and <code>io2</code> volumes only. For more information, see \n\t\t<a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-volumes-multi.html\">\n\t\t\tAmazon EBS Multi-Attach</a> in the <i>Amazon Elastic Compute Cloud User Guide</i>.</p>"
                     }
                 }
@@ -58156,6 +62453,7 @@
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcId"
@@ -58193,12 +62491,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ConnectionNotificationId": {
                     "target": "com.amazonaws.ec2#ConnectionNotificationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the notification.</p>",
                         "smithy.api#required": {}
                     }
@@ -58224,6 +62525,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -58236,12 +62539,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "VpcEndpointId": {
                     "target": "com.amazonaws.ec2#VpcEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the endpoint.</p>",
                         "smithy.api#required": {}
                     }
@@ -58249,6 +62555,8 @@
                 "ResetPolicy": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>(Gateway endpoint) Specify <code>true</code> to reset the policy document to the\n            default policy. The default policy allows full access to the service.</p>"
                     }
                 },
@@ -58315,6 +62623,8 @@
                 "PrivateDnsEnabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>(Interface endpoint) Indicates whether a private hosted zone is associated with the\n            VPC.</p>"
                     }
                 }
@@ -58330,6 +62640,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -58354,12 +62666,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ServiceId": {
                     "target": "com.amazonaws.ec2#VpcEndpointServiceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the service.</p>",
                         "smithy.api#required": {}
                     }
@@ -58373,12 +62688,16 @@
                 "RemovePrivateDnsName": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>(Interface endpoint configuration) Removes the private DNS name of the endpoint service.</p>"
                     }
                 },
                 "AcceptanceRequired": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether requests to create an endpoint to your service must be accepted.</p>"
                     }
                 },
@@ -58433,6 +62752,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -58457,12 +62778,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ServiceId": {
                     "target": "com.amazonaws.ec2#VpcEndpointServiceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the service.</p>",
                         "smithy.api#required": {}
                     }
@@ -58470,6 +62794,7 @@
                 "PayerResponsibility": {
                     "target": "com.amazonaws.ec2#PayerResponsibility",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The entity that is responsible for the endpoint costs. The default is the endpoint owner.\n            If you set the payer responsibility to the service owner, you cannot set it back to the\n            endpoint owner.</p>",
                         "smithy.api#required": {}
                     }
@@ -58483,6 +62808,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -58507,12 +62834,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ServiceId": {
                     "target": "com.amazonaws.ec2#VpcEndpointServiceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the service.</p>",
                         "smithy.api#required": {}
                     }
@@ -58534,10 +62864,20 @@
         "com.amazonaws.ec2#ModifyVpcEndpointServicePermissionsResult": {
             "type": "structure",
             "members": {
+                "AddedPrincipals": {
+                    "target": "com.amazonaws.ec2#AddedPrincipalSet",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "AddedPrincipalSet",
+                        "smithy.api#documentation": "<p>Information about the added principals.</p>",
+                        "smithy.api#xmlName": "addedPrincipalSet"
+                    }
+                },
                 "ReturnValue": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -58568,6 +62908,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -58580,6 +62922,7 @@
                 "VpcPeeringConnectionId": {
                     "target": "com.amazonaws.ec2#VpcPeeringConnectionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC peering connection.</p>",
                         "smithy.api#required": {}
                     }
@@ -58625,6 +62968,7 @@
                 "VpcId": {
                     "target": "com.amazonaws.ec2#VpcId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC.</p>",
                         "smithy.api#required": {}
                     }
@@ -58632,6 +62976,7 @@
                 "InstanceTenancy": {
                     "target": "com.amazonaws.ec2#VpcTenancy",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The instance tenancy attribute for the VPC. </p>",
                         "smithy.api#required": {}
                     }
@@ -58639,6 +62984,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -58651,6 +62998,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, returns an\n            error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -58687,6 +63036,7 @@
                 "VpnConnectionId": {
                     "target": "com.amazonaws.ec2#VpnConnectionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Site-to-Site VPN connection. </p>",
                         "smithy.api#required": {}
                     }
@@ -58718,6 +63068,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -58741,6 +63093,7 @@
                 "VpnConnectionId": {
                     "target": "com.amazonaws.ec2#VpnConnectionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPN connection.</p>",
                         "smithy.api#required": {}
                     }
@@ -58766,6 +63119,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -58801,6 +63156,7 @@
                 "VpnConnectionId": {
                     "target": "com.amazonaws.ec2#VpnConnectionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Amazon Web Services Site-to-Site VPN connection.</p>",
                         "smithy.api#required": {}
                     }
@@ -58808,6 +63164,7 @@
                 "VpnTunnelOutsideIpAddress": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The external IP address of the VPN tunnel.</p>",
                         "smithy.api#required": {}
                     }
@@ -58815,6 +63172,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -58850,6 +63209,7 @@
                 "VpnConnectionId": {
                     "target": "com.amazonaws.ec2#VpnConnectionId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Amazon Web Services Site-to-Site VPN connection.</p>",
                         "smithy.api#required": {}
                     }
@@ -58857,6 +63217,7 @@
                 "VpnTunnelOutsideIpAddress": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The external IP address of the VPN tunnel.</p>",
                         "smithy.api#required": {}
                     }
@@ -58864,6 +63225,7 @@
                 "TunnelOptions": {
                     "target": "com.amazonaws.ec2#ModifyVpnTunnelOptionsSpecification",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The tunnel options to modify.</p>",
                         "smithy.api#required": {}
                     }
@@ -58871,6 +63233,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -58912,36 +63276,48 @@
                 "Phase1LifetimeSeconds": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The lifetime for phase 1 of the IKE negotiation, in seconds.</p>\n        <p>Constraints: A value between 900 and 28,800.</p>\n        <p>Default: <code>28800</code>\n         </p>"
                     }
                 },
                 "Phase2LifetimeSeconds": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The lifetime for phase 2 of the IKE negotiation, in seconds.</p>\n        <p>Constraints: A value between 900 and 3,600. The value must be less than the value for\n                <code>Phase1LifetimeSeconds</code>.</p>\n        <p>Default: <code>3600</code>\n         </p>"
                     }
                 },
                 "RekeyMarginTimeSeconds": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The margin time, in seconds, before the phase 2 lifetime expires, during which the\n                Amazon Web Services side of the VPN connection performs an IKE rekey. The exact time\n            of the rekey is randomly selected based on the value for\n                <code>RekeyFuzzPercentage</code>.</p>\n        <p>Constraints: A value between 60 and half of <code>Phase2LifetimeSeconds</code>.</p>\n        <p>Default: <code>540</code>\n         </p>"
                     }
                 },
                 "RekeyFuzzPercentage": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The percentage of the rekey window (determined by <code>RekeyMarginTimeSeconds</code>)\n            during which the rekey time is randomly selected.</p>\n        <p>Constraints: A value between 0 and 100.</p>\n        <p>Default: <code>100</code>\n         </p>"
                     }
                 },
                 "ReplayWindowSize": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of packets in an IKE replay window.</p>\n        <p>Constraints: A value between 64 and 2048.</p>\n        <p>Default: <code>1024</code>\n         </p>"
                     }
                 },
                 "DPDTimeoutSeconds": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of seconds after which a DPD timeout occurs.</p>\n        <p>Constraints: A value greater than or equal to 30.</p>\n        <p>Default: <code>30</code>\n         </p>"
                     }
                 },
@@ -59035,6 +63411,7 @@
                 "InstanceIds": {
                     "target": "com.amazonaws.ec2#InstanceIdStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the instances.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "InstanceId"
@@ -59044,6 +63421,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -59080,26 +63459,32 @@
             }
         },
         "com.amazonaws.ec2#MonitoringState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
-                    },
-                    {
-                        "value": "disabling",
-                        "name": "disabling"
-                    },
-                    {
-                        "value": "enabled",
-                        "name": "enabled"
-                    },
-                    {
-                        "value": "pending",
-                        "name": "pending"
+            "type": "enum",
+            "members": {
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
                     }
-                ]
+                },
+                "disabling": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabling"
+                    }
+                },
+                "enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled"
+                    }
+                },
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#MoveAddressToVpc": {
@@ -59121,6 +63506,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -59129,6 +63516,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PublicIp",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Elastic IP address.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "publicIp"
@@ -59175,12 +63563,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The BYOIP CIDR.</p>",
                         "smithy.api#required": {}
                     }
@@ -59188,6 +63579,7 @@
                 "IpamPoolId": {
                     "target": "com.amazonaws.ec2#IpamPoolId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IPAM pool ID.</p>",
                         "smithy.api#required": {}
                     }
@@ -59195,6 +63587,7 @@
                 "IpamPoolOwner": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Amazon Web Services account ID of the owner of the IPAM pool.</p>",
                         "smithy.api#required": {}
                     }
@@ -59214,18 +63607,20 @@
             }
         },
         "com.amazonaws.ec2#MoveStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "movingToVpc",
-                        "name": "movingToVpc"
-                    },
-                    {
-                        "value": "restoringToClassic",
-                        "name": "restoringToClassic"
+            "type": "enum",
+            "members": {
+                "movingToVpc": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "movingToVpc"
                     }
-                ]
+                },
+                "restoringToClassic": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "restoringToClassic"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#MovingAddressStatus": {
@@ -59262,18 +63657,20 @@
             }
         },
         "com.amazonaws.ec2#MulticastSupportValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#NatGateway": {
@@ -59451,37 +63848,42 @@
             }
         },
         "com.amazonaws.ec2#NatGatewayState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "PENDING"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "FAILED"
-                    },
-                    {
-                        "value": "available",
-                        "name": "AVAILABLE"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "DELETING"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "DELETED"
+            "type": "enum",
+            "members": {
+                "PENDING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "FAILED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "AVAILABLE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "DELETING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "DELETED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#NetmaskLength": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#NetworkAcl": {
             "type": "structure",
@@ -59506,6 +63908,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Default",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether this is the default network ACL for the VPC.</p>",
                         "smithy.api#xmlName": "default"
                     }
@@ -59606,6 +64010,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Egress",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the rule is an egress rule (applied to traffic leaving the subnet).</p>",
                         "smithy.api#xmlName": "egress"
                     }
@@ -59654,6 +64060,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RuleNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The rule number for the entry. ACL entries are processed in ascending order by rule number.</p>",
                         "smithy.api#xmlName": "ruleNumber"
                     }
@@ -59694,10 +64102,7 @@
             }
         },
         "com.amazonaws.ec2#NetworkCardIndex": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#NetworkCardInfo": {
             "type": "structure",
@@ -59971,6 +64376,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AnalyzedEniCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of network interfaces analyzed.</p>",
                         "smithy.api#xmlName": "analyzedEniCount"
                     }
@@ -60133,6 +64540,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkPathFound",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the destination is reachable from the source.</p>",
                         "smithy.api#xmlName": "networkPathFound"
                     }
@@ -60206,6 +64615,7 @@
         "com.amazonaws.ec2#NetworkInsightsMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 100
@@ -60283,6 +64693,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DestinationPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The destination port.</p>",
                         "smithy.api#xmlName": "destinationPort"
                     }
@@ -60467,6 +64879,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RequesterManaged",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the network interface is being managed by Amazon Web Services.</p>",
                         "smithy.api#xmlName": "requesterManaged"
                     }
@@ -60475,6 +64889,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SourceDestCheck",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether source/destination checking is enabled.</p>",
                         "smithy.api#xmlName": "sourceDestCheck"
                     }
@@ -60515,6 +64931,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DenyAllIgwTraffic",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether a network interface with an IPv6 address is unreachable from the \n            public internet. If the value is <code>true</code>, inbound traffic from the internet \n            is dropped and you cannot assign an elastic IP address to the network interface. The \n            network interface is reachable from peered VPCs and resources connected through a \n            transit gateway, including on-premises networks.</p>",
                         "smithy.api#xmlName": "denyAllIgwTraffic"
                     }
@@ -60523,6 +64941,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Ipv6Native",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether this is an IPv6 only network interface.</p>",
                         "smithy.api#xmlName": "ipv6Native"
                     }
@@ -60627,6 +65047,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeleteOnTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the network interface is deleted when the instance is terminated.</p>",
                         "smithy.api#xmlName": "deleteOnTermination"
                     }
@@ -60635,6 +65057,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeviceIndex",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The device index of the network interface attachment on the instance.</p>",
                         "smithy.api#xmlName": "deviceIndex"
                     }
@@ -60643,6 +65067,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkCardIndex",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The index of the network card.</p>",
                         "smithy.api#xmlName": "networkCardIndex"
                     }
@@ -60691,6 +65117,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeleteOnTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the network interface is deleted when the instance is terminated.</p>",
                         "smithy.api#xmlName": "deleteOnTermination"
                     }
@@ -60704,26 +65132,32 @@
             "type": "string"
         },
         "com.amazonaws.ec2#NetworkInterfaceAttribute": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "description",
-                        "name": "description"
-                    },
-                    {
-                        "value": "groupSet",
-                        "name": "groupSet"
-                    },
-                    {
-                        "value": "sourceDestCheck",
-                        "name": "sourceDestCheck"
-                    },
-                    {
-                        "value": "attachment",
-                        "name": "attachment"
+            "type": "enum",
+            "members": {
+                "description": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "description"
                     }
-                ]
+                },
+                "groupSet": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "groupSet"
+                    }
+                },
+                "sourceDestCheck": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "sourceDestCheck"
+                    }
+                },
+                "attachment": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "attachment"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#NetworkInterfaceCount": {
@@ -60733,6 +65167,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Min",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum number of network interfaces. If this parameter is not specified, there is no\n         minimum limit.</p>",
                         "smithy.api#xmlName": "min"
                     }
@@ -60741,6 +65177,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Max",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of network interfaces. If this parameter is not specified, there is no\n         maximum limit.</p>",
                         "smithy.api#xmlName": "max"
                     }
@@ -60756,12 +65194,16 @@
                 "Min": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum number of network interfaces. To specify no minimum limit, omit this\n         parameter.</p>"
                     }
                 },
                 "Max": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of network interfaces. To specify no maximum limit, omit this\n         parameter.</p>"
                     }
                 }
@@ -60771,22 +65213,26 @@
             }
         },
         "com.amazonaws.ec2#NetworkInterfaceCreationType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "efa",
-                        "name": "efa"
-                    },
-                    {
-                        "value": "branch",
-                        "name": "branch"
-                    },
-                    {
-                        "value": "trunk",
-                        "name": "trunk"
+            "type": "enum",
+            "members": {
+                "efa": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "efa"
                     }
-                ]
+                },
+                "branch": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "branch"
+                    }
+                },
+                "trunk": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "trunk"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#NetworkInterfaceId": {
@@ -60934,26 +65380,32 @@
             }
         },
         "com.amazonaws.ec2#NetworkInterfacePermissionStateCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "granted",
-                        "name": "granted"
-                    },
-                    {
-                        "value": "revoking",
-                        "name": "revoking"
-                    },
-                    {
-                        "value": "revoked",
-                        "name": "revoked"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "granted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "granted"
+                    }
+                },
+                "revoking": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "revoking"
+                    }
+                },
+                "revoked": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "revoked"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#NetworkInterfacePrivateIpAddress": {
@@ -60971,6 +65423,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Primary",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether this IPv4 address is the primary private IPv4 address of the network interface.</p>",
                         "smithy.api#xmlName": "primary"
                     }
@@ -61006,105 +65460,145 @@
             }
         },
         "com.amazonaws.ec2#NetworkInterfaceStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "associated",
-                        "name": "associated"
-                    },
-                    {
-                        "value": "attaching",
-                        "name": "attaching"
-                    },
-                    {
-                        "value": "in-use",
-                        "name": "in_use"
-                    },
-                    {
-                        "value": "detaching",
-                        "name": "detaching"
+            "type": "enum",
+            "members": {
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
                     }
-                ]
+                },
+                "associated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associated"
+                    }
+                },
+                "attaching": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "attaching"
+                    }
+                },
+                "in_use": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "in-use"
+                    }
+                },
+                "detaching": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "detaching"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#NetworkInterfaceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "interface",
-                        "name": "interface"
-                    },
-                    {
-                        "value": "natGateway",
-                        "name": "natGateway"
-                    },
-                    {
-                        "value": "efa",
-                        "name": "efa"
-                    },
-                    {
-                        "value": "trunk",
-                        "name": "trunk"
-                    },
-                    {
-                        "value": "load_balancer",
-                        "name": "load_balancer"
-                    },
-                    {
-                        "value": "network_load_balancer",
-                        "name": "network_load_balancer"
-                    },
-                    {
-                        "value": "vpc_endpoint",
-                        "name": "vpc_endpoint"
-                    },
-                    {
-                        "value": "branch",
-                        "name": "branch"
-                    },
-                    {
-                        "value": "transit_gateway",
-                        "name": "transit_gateway"
-                    },
-                    {
-                        "value": "lambda",
-                        "name": "lambda"
-                    },
-                    {
-                        "value": "quicksight",
-                        "name": "quicksight"
-                    },
-                    {
-                        "value": "global_accelerator_managed",
-                        "name": "global_accelerator_managed"
-                    },
-                    {
-                        "value": "api_gateway_managed",
-                        "name": "api_gateway_managed"
-                    },
-                    {
-                        "value": "gateway_load_balancer",
-                        "name": "gateway_load_balancer"
-                    },
-                    {
-                        "value": "gateway_load_balancer_endpoint",
-                        "name": "gateway_load_balancer_endpoint"
-                    },
-                    {
-                        "value": "iot_rules_managed",
-                        "name": "iot_rules_managed"
-                    },
-                    {
-                        "value": "aws_codestar_connections_managed",
-                        "name": "aws_codestar_connections_managed"
+            "type": "enum",
+            "members": {
+                "interface": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "interface"
                     }
-                ]
+                },
+                "natGateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "natGateway"
+                    }
+                },
+                "efa": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "efa"
+                    }
+                },
+                "trunk": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "trunk"
+                    }
+                },
+                "load_balancer": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "load_balancer"
+                    }
+                },
+                "network_load_balancer": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "network_load_balancer"
+                    }
+                },
+                "vpc_endpoint": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vpc_endpoint"
+                    }
+                },
+                "branch": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "branch"
+                    }
+                },
+                "transit_gateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "transit_gateway"
+                    }
+                },
+                "lambda": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "lambda"
+                    }
+                },
+                "quicksight": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "quicksight"
+                    }
+                },
+                "global_accelerator_managed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "global_accelerator_managed"
+                    }
+                },
+                "api_gateway_managed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "api_gateway_managed"
+                    }
+                },
+                "gateway_load_balancer": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "gateway_load_balancer"
+                    }
+                },
+                "gateway_load_balancer_endpoint": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "gateway_load_balancer_endpoint"
+                    }
+                },
+                "iot_rules_managed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "iot_rules_managed"
+                    }
+                },
+                "aws_codestar_connections_managed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "aws_codestar_connections_managed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#NetworkPerformance": {
@@ -61164,67 +65658,81 @@
             }
         },
         "com.amazonaws.ec2#OfferingClassType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "standard",
-                        "name": "STANDARD"
-                    },
-                    {
-                        "value": "convertible",
-                        "name": "CONVERTIBLE"
+            "type": "enum",
+            "members": {
+                "STANDARD": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "standard"
                     }
-                ]
+                },
+                "CONVERTIBLE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "convertible"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#OfferingId": {
             "type": "string"
         },
         "com.amazonaws.ec2#OfferingTypeValues": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Heavy Utilization",
-                        "name": "Heavy_Utilization"
-                    },
-                    {
-                        "value": "Medium Utilization",
-                        "name": "Medium_Utilization"
-                    },
-                    {
-                        "value": "Light Utilization",
-                        "name": "Light_Utilization"
-                    },
-                    {
-                        "value": "No Upfront",
-                        "name": "No_Upfront"
-                    },
-                    {
-                        "value": "Partial Upfront",
-                        "name": "Partial_Upfront"
-                    },
-                    {
-                        "value": "All Upfront",
-                        "name": "All_Upfront"
+            "type": "enum",
+            "members": {
+                "Heavy_Utilization": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Heavy Utilization"
                     }
-                ]
+                },
+                "Medium_Utilization": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Medium Utilization"
+                    }
+                },
+                "Light_Utilization": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Light Utilization"
+                    }
+                },
+                "No_Upfront": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "No Upfront"
+                    }
+                },
+                "Partial_Upfront": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Partial Upfront"
+                    }
+                },
+                "All_Upfront": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "All Upfront"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#OnDemandAllocationStrategy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "lowestPrice",
-                        "name": "LOWEST_PRICE"
-                    },
-                    {
-                        "value": "prioritized",
-                        "name": "PRIORITIZED"
+            "type": "enum",
+            "members": {
+                "LOWEST_PRICE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "lowestPrice"
                     }
-                ]
+                },
+                "PRIORITIZED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "prioritized"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#OnDemandOptions": {
@@ -61250,6 +65758,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SingleInstanceType",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates that the fleet uses a single instance type to launch all On-Demand Instances in the\n         fleet.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>",
                         "smithy.api#xmlName": "singleInstanceType"
                     }
@@ -61258,6 +65768,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SingleAvailabilityZone",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates that the fleet launches all On-Demand Instances into a single Availability Zone.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>",
                         "smithy.api#xmlName": "singleAvailabilityZone"
                     }
@@ -61266,6 +65778,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MinTargetCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum target capacity for On-Demand Instances in the fleet. If the minimum target capacity is\n         not reached, the fleet launches no instances.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>\n         <p>At least one of the following must be specified: <code>SingleAvailabilityZone</code> |\n         <code>SingleInstanceType</code>\n         </p>",
                         "smithy.api#xmlName": "minTargetCapacity"
                     }
@@ -61301,18 +65815,24 @@
                 "SingleInstanceType": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates that the fleet uses a single instance type to launch all On-Demand Instances in the\n         fleet.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>"
                     }
                 },
                 "SingleAvailabilityZone": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates that the fleet launches all On-Demand Instances into a single Availability Zone.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>"
                     }
                 },
                 "MinTargetCapacity": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum target capacity for On-Demand Instances in the fleet. If the minimum target capacity is\n         not reached, the fleet launches no instances.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>\n         <p>At least one of the following must be specified: <code>SingleAvailabilityZone</code> |\n         <code>SingleInstanceType</code>\n         </p>"
                     }
                 },
@@ -61328,18 +65848,20 @@
             }
         },
         "com.amazonaws.ec2#OperationType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "add",
-                        "name": "add"
-                    },
-                    {
-                        "value": "remove",
-                        "name": "remove"
+            "type": "enum",
+            "members": {
+                "add": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "add"
                     }
-                ]
+                },
+                "remove": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "remove"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#OrganizationArnStringList": {
@@ -61497,26 +66019,32 @@
             }
         },
         "com.amazonaws.ec2#PartitionLoadFrequency": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "none",
-                        "name": "NONE"
-                    },
-                    {
-                        "value": "daily",
-                        "name": "DAILY"
-                    },
-                    {
-                        "value": "weekly",
-                        "name": "WEEKLY"
-                    },
-                    {
-                        "value": "monthly",
-                        "name": "MONTHLY"
+            "type": "enum",
+            "members": {
+                "NONE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "none"
                     }
-                ]
+                },
+                "DAILY": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "daily"
+                    }
+                },
+                "WEEKLY": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "weekly"
+                    }
+                },
+                "MONTHLY": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "monthly"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#PathComponent": {
@@ -61526,6 +66054,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SequenceNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The sequence number.</p>",
                         "smithy.api#xmlName": "sequenceNumber"
                     }
@@ -61701,33 +66231,37 @@
             }
         },
         "com.amazonaws.ec2#PayerResponsibility": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ServiceOwner",
-                        "name": "ServiceOwner"
+            "type": "enum",
+            "members": {
+                "ServiceOwner": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ServiceOwner"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#PaymentOption": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "AllUpfront",
-                        "name": "ALL_UPFRONT"
-                    },
-                    {
-                        "value": "PartialUpfront",
-                        "name": "PARTIAL_UPFRONT"
-                    },
-                    {
-                        "value": "NoUpfront",
-                        "name": "NO_UPFRONT"
+            "type": "enum",
+            "members": {
+                "ALL_UPFRONT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "AllUpfront"
                     }
-                ]
+                },
+                "PARTIAL_UPFRONT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "PartialUpfront"
+                    }
+                },
+                "NO_UPFRONT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "NoUpfront"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#PciId": {
@@ -61793,6 +66327,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AllowDnsResolutionFromRemoteVpc",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If true, the public DNS hostnames of instances in the specified VPC resolve to private\n            IP addresses when queried from instances in the peer VPC.</p>",
                         "smithy.api#xmlName": "allowDnsResolutionFromRemoteVpc"
                     }
@@ -61801,6 +66337,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AllowEgressFromLocalClassicLinkToRemoteVpc",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If true, enables outbound communication from an EC2-Classic instance that's linked to\n            a local VPC using ClassicLink to instances in a peer VPC.</p>",
                         "smithy.api#xmlName": "allowEgressFromLocalClassicLinkToRemoteVpc"
                     }
@@ -61809,6 +66347,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AllowEgressFromLocalVpcToRemoteClassicLink",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If true, enables outbound communication from instances in a local VPC to an\n            EC2-Classic instance that's linked to a peer VPC using ClassicLink.</p>",
                         "smithy.api#xmlName": "allowEgressFromLocalVpcToRemoteClassicLink"
                     }
@@ -61824,18 +66364,24 @@
                 "AllowDnsResolutionFromRemoteVpc": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If true, enables a local VPC to resolve public DNS hostnames to private IP addresses when queried from instances in the peer VPC.</p>"
                     }
                 },
                 "AllowEgressFromLocalClassicLinkToRemoteVpc": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If true, enables outbound communication from an EC2-Classic instance that's linked to\n            a local VPC using ClassicLink to instances in a peer VPC.</p>"
                     }
                 },
                 "AllowEgressFromLocalVpcToRemoteClassicLink": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If true, enables outbound communication from instances in a local VPC to an\n            EC2-Classic instance that's linked to a peer VPC using ClassicLink.</p>"
                     }
                 }
@@ -61885,14 +66431,14 @@
             }
         },
         "com.amazonaws.ec2#PermissionGroup": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "all",
-                        "name": "all"
+            "type": "enum",
+            "members": {
+                "all": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "all"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#Phase1DHGroupNumbersList": {
@@ -61911,6 +66457,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Value",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The Diffie-Hellmann group number.</p>",
                         "smithy.api#xmlName": "value"
                     }
@@ -61935,6 +66483,8 @@
                 "Value": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The Diffie-Hellmann group number.</p>"
                     }
                 }
@@ -62055,6 +66605,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Value",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The Diffie-Hellmann group number.</p>",
                         "smithy.api#xmlName": "value"
                     }
@@ -62079,6 +66631,8 @@
                 "Value": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The Diffie-Hellmann group number.</p>"
                     }
                 }
@@ -62214,6 +66768,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PartitionNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of the partition that the instance is in. Valid only if the placement group\n            strategy is set to <code>partition</code>.</p>\n        <p>This parameter is not supported by <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateFleet\">CreateFleet</a>.</p>",
                         "smithy.api#xmlName": "partitionNumber"
                     }
@@ -62286,6 +66842,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PartitionCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of partitions. Valid only if <b>strategy</b> is\n            set to <code>partition</code>.</p>",
                         "smithy.api#xmlName": "partitionCount"
                     }
@@ -62374,45 +66932,55 @@
             "type": "string"
         },
         "com.amazonaws.ec2#PlacementGroupState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#PlacementGroupStrategy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "cluster",
-                        "name": "cluster"
-                    },
-                    {
-                        "value": "partition",
-                        "name": "partition"
-                    },
-                    {
-                        "value": "spread",
-                        "name": "spread"
+            "type": "enum",
+            "members": {
+                "cluster": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cluster"
                     }
-                ]
+                },
+                "partition": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "partition"
+                    }
+                },
+                "spread": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "spread"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#PlacementGroupStrategyList": {
@@ -62447,33 +67015,37 @@
             }
         },
         "com.amazonaws.ec2#PlacementStrategy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "cluster",
-                        "name": "cluster"
-                    },
-                    {
-                        "value": "spread",
-                        "name": "spread"
-                    },
-                    {
-                        "value": "partition",
-                        "name": "partition"
+            "type": "enum",
+            "members": {
+                "cluster": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cluster"
                     }
-                ]
+                },
+                "spread": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "spread"
+                    }
+                },
+                "partition": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "partition"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#PlatformValues": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Windows",
-                        "name": "Windows"
+            "type": "enum",
+            "members": {
+                "Windows": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Windows"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#PoolCidrBlock": {
@@ -62504,6 +67076,7 @@
         "com.amazonaws.ec2#PoolMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 10
@@ -62513,6 +67086,7 @@
         "com.amazonaws.ec2#Port": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 65535
@@ -62526,6 +67100,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "From",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The first port in the range.</p>",
                         "smithy.api#xmlName": "from"
                     }
@@ -62534,6 +67110,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "To",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The last port in the range.</p>",
                         "smithy.api#xmlName": "to"
                     }
@@ -62695,6 +67273,7 @@
         "com.amazonaws.ec2#PrefixListMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 100
@@ -62723,58 +67302,80 @@
             }
         },
         "com.amazonaws.ec2#PrefixListState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "create-in-progress",
-                        "name": "create_in_progress"
-                    },
-                    {
-                        "value": "create-complete",
-                        "name": "create_complete"
-                    },
-                    {
-                        "value": "create-failed",
-                        "name": "create_failed"
-                    },
-                    {
-                        "value": "modify-in-progress",
-                        "name": "modify_in_progress"
-                    },
-                    {
-                        "value": "modify-complete",
-                        "name": "modify_complete"
-                    },
-                    {
-                        "value": "modify-failed",
-                        "name": "modify_failed"
-                    },
-                    {
-                        "value": "restore-in-progress",
-                        "name": "restore_in_progress"
-                    },
-                    {
-                        "value": "restore-complete",
-                        "name": "restore_complete"
-                    },
-                    {
-                        "value": "restore-failed",
-                        "name": "restore_failed"
-                    },
-                    {
-                        "value": "delete-in-progress",
-                        "name": "delete_in_progress"
-                    },
-                    {
-                        "value": "delete-complete",
-                        "name": "delete_complete"
-                    },
-                    {
-                        "value": "delete-failed",
-                        "name": "delete_failed"
+            "type": "enum",
+            "members": {
+                "create_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-in-progress"
                     }
-                ]
+                },
+                "create_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-complete"
+                    }
+                },
+                "create_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "create-failed"
+                    }
+                },
+                "modify_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-in-progress"
+                    }
+                },
+                "modify_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-complete"
+                    }
+                },
+                "modify_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modify-failed"
+                    }
+                },
+                "restore_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "restore-in-progress"
+                    }
+                },
+                "restore_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "restore-complete"
+                    }
+                },
+                "restore_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "restore-failed"
+                    }
+                },
+                "delete_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-in-progress"
+                    }
+                },
+                "delete_complete": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-complete"
+                    }
+                },
+                "delete_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "delete-failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#PriceSchedule": {
@@ -62784,6 +67385,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Active",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>The current price schedule, as determined by the term remaining for the Reserved Instance in the listing.</p>\n         <p>A specific price schedule is always in effect, but only one price schedule can be active at any time. Take, for example, a Reserved Instance listing that has five months remaining in its term. When you specify price schedules for five months and two months, this means that schedule 1, covering the first three months of the remaining term, will be active during months 5, 4, and 3. Then schedule 2, covering the last two months of the term, will be active for months 2 and 1.</p>",
                         "smithy.api#xmlName": "active"
                     }
@@ -62800,6 +67403,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Price",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The fixed price for the term.</p>",
                         "smithy.api#xmlName": "price"
                     }
@@ -62808,6 +67413,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Term",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of months remaining in the reservation. For example, 2 is the second to the last month before the capacity reservation expires.</p>",
                         "smithy.api#xmlName": "term"
                     }
@@ -62841,6 +67448,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Price",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The fixed price for the term.</p>",
                         "smithy.api#xmlName": "price"
                     }
@@ -62849,6 +67458,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Term",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of months remaining in the reservation. For example, 2 is the second to the last month before the capacity reservation expires.</p>",
                         "smithy.api#xmlName": "term"
                     }
@@ -62874,6 +67485,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Count",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of reservations available for the price.</p>",
                         "smithy.api#xmlName": "count"
                     }
@@ -62882,6 +67495,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Price",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The price per instance.</p>",
                         "smithy.api#xmlName": "price"
                     }
@@ -62934,34 +67549,44 @@
             }
         },
         "com.amazonaws.ec2#PrincipalType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "All",
-                        "name": "All"
-                    },
-                    {
-                        "value": "Service",
-                        "name": "Service"
-                    },
-                    {
-                        "value": "OrganizationUnit",
-                        "name": "OrganizationUnit"
-                    },
-                    {
-                        "value": "Account",
-                        "name": "Account"
-                    },
-                    {
-                        "value": "User",
-                        "name": "User"
-                    },
-                    {
-                        "value": "Role",
-                        "name": "Role"
+            "type": "enum",
+            "members": {
+                "All": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "All"
                     }
-                ]
+                },
+                "Service": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Service"
+                    }
+                },
+                "OrganizationUnit": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "OrganizationUnit"
+                    }
+                },
+                "Account": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Account"
+                    }
+                },
+                "User": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "User"
+                    }
+                },
+                "Role": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Role"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#PrivateDnsDetails": {
@@ -63044,6 +67669,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnableResourceNameDnsARecord",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostnames with DNS A\n            records.</p>",
                         "smithy.api#xmlName": "enableResourceNameDnsARecord"
                     }
@@ -63052,6 +67679,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnableResourceNameDnsAAAARecord",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostname with DNS AAAA\n            records.</p>",
                         "smithy.api#xmlName": "enableResourceNameDnsAAAARecord"
                     }
@@ -63073,12 +67702,16 @@
                 "EnableResourceNameDnsARecord": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostnames with DNS A\n            records.</p>"
                     }
                 },
                 "EnableResourceNameDnsAAAARecord": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostnames with DNS AAAA\n            records.</p>"
                     }
                 }
@@ -63102,6 +67735,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnableResourceNameDnsARecord",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostnames with DNS A\n            records.</p>",
                         "smithy.api#xmlName": "enableResourceNameDnsARecord"
                     }
@@ -63110,6 +67745,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnableResourceNameDnsAAAARecord",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to respond to DNS queries for instance hostnames with DNS AAAA\n            records.</p>",
                         "smithy.api#xmlName": "enableResourceNameDnsAAAARecord"
                     }
@@ -63135,6 +67772,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Primary",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the private IPv4 address is the primary private IPv4 address. Only\n            one IPv4 address can be designated as primary.</p>",
                         "smithy.api#xmlName": "primary"
                     }
@@ -63195,10 +67834,7 @@
             }
         },
         "com.amazonaws.ec2#ProcessorSustainedClockSpeed": {
-            "type": "double",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "double"
         },
         "com.amazonaws.ec2#ProductCode": {
             "type": "structure",
@@ -63243,18 +67879,20 @@
             }
         },
         "com.amazonaws.ec2#ProductCodeValues": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "devpay",
-                        "name": "devpay"
-                    },
-                    {
-                        "value": "marketplace",
-                        "name": "marketplace"
+            "type": "enum",
+            "members": {
+                "devpay": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "devpay"
                     }
-                ]
+                },
+                "marketplace": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "marketplace"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ProductDescriptionList": {
@@ -63289,18 +67927,20 @@
             }
         },
         "com.amazonaws.ec2#Protocol": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "tcp",
-                        "name": "tcp"
-                    },
-                    {
-                        "value": "udp",
-                        "name": "udp"
+            "type": "enum",
+            "members": {
+                "tcp": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "tcp"
                     }
-                ]
+                },
+                "udp": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "udp"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ProtocolList": {
@@ -63313,14 +67953,14 @@
             }
         },
         "com.amazonaws.ec2#ProtocolValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "gre",
-                        "name": "gre"
+            "type": "enum",
+            "members": {
+                "gre": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "gre"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#ProvisionByoipCidr": {
@@ -63341,6 +67981,7 @@
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The public IPv4 or IPv6 address range, in CIDR notation. The most specific IPv4 prefix that you can \n         specify is /24. The most specific IPv6 prefix you can specify is /56. The address range cannot overlap with another address range that you've \n         brought to this or another Region.</p>",
                         "smithy.api#required": {}
                     }
@@ -63354,6 +67995,8 @@
                 "PubliclyAdvertisable": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>(IPv6 only) Indicate whether the address range will be publicly advertised to the\n            internet.</p>\n        <p>Default: true</p>"
                     }
                 },
@@ -63366,6 +68009,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -63379,6 +68024,8 @@
                 "MultiRegion": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Reserved.</p>"
                     }
                 }
@@ -63415,12 +68062,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamPoolId": {
                     "target": "com.amazonaws.ec2#IpamPoolId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPAM pool to which you want to assign a CIDR.</p>",
                         "smithy.api#required": {}
                     }
@@ -63470,12 +68120,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamPoolId": {
                     "target": "com.amazonaws.ec2#IpamPoolId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPAM pool you would like to use to allocate this CIDR.</p>",
                         "smithy.api#required": {}
                     }
@@ -63483,6 +68136,7 @@
                 "PoolId": {
                     "target": "com.amazonaws.ec2#Ipv4PoolEc2Id",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the public IPv4 pool you would like to use for this CIDR.</p>",
                         "smithy.api#required": {}
                     }
@@ -63490,6 +68144,8 @@
                 "NetmaskLength": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The netmask length of the CIDR you would like to allocate to the public IPv4 pool.</p>",
                         "smithy.api#required": {}
                     }
@@ -63639,6 +68295,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalAddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of addresses.</p>",
                         "smithy.api#xmlName": "totalAddressCount"
                     }
@@ -63647,6 +68305,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalAvailableAddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of available addresses.</p>",
                         "smithy.api#xmlName": "totalAvailableAddressCount"
                     }
@@ -63704,6 +68364,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of addresses in the range.</p>",
                         "smithy.api#xmlName": "addressCount"
                     }
@@ -63712,6 +68374,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AvailableAddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of available addresses in the range.</p>",
                         "smithy.api#xmlName": "availableAddressCount"
                     }
@@ -63754,6 +68418,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Duration",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The duration of the reservation's term in seconds.</p>",
                         "smithy.api#xmlName": "duration"
                     }
@@ -63841,6 +68507,7 @@
                 "HostIdSet": {
                     "target": "com.amazonaws.ec2#RequestHostIdSet",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the Dedicated Hosts with which the reservation will be associated.</p>",
                         "smithy.api#required": {}
                     }
@@ -63854,6 +68521,7 @@
                 "OfferingId": {
                     "target": "com.amazonaws.ec2#OfferingId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the offering.</p>",
                         "smithy.api#required": {}
                     }
@@ -63918,6 +68586,8 @@
                 "InstanceCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of instances.</p>",
                         "smithy.api#required": {}
                     }
@@ -63925,6 +68595,7 @@
                 "PurchaseToken": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The purchase token.</p>",
                         "smithy.api#required": {}
                     }
@@ -63966,6 +68637,8 @@
                 "InstanceCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of Reserved Instances to purchase.</p>",
                         "smithy.api#required": {}
                     }
@@ -63973,6 +68646,7 @@
                 "ReservedInstancesOfferingId": {
                     "target": "com.amazonaws.ec2#ReservedInstancesOfferingId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Reserved Instance offering to purchase.</p>",
                         "smithy.api#required": {}
                     }
@@ -63981,6 +68655,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n       and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n       Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -64045,12 +68721,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "PurchaseRequests": {
                     "target": "com.amazonaws.ec2#PurchaseRequestSet",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The purchase requests.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "PurchaseRequest"
@@ -64144,6 +68823,7 @@
                 "InstanceIds": {
                     "target": "com.amazonaws.ec2#InstanceIdStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The instance IDs.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "InstanceId"
@@ -64153,6 +68833,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -64166,6 +68848,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Amount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The amount of the recurring charge.</p>",
                         "smithy.api#xmlName": "amount"
                     }
@@ -64184,14 +68868,14 @@
             }
         },
         "com.amazonaws.ec2#RecurringChargeFrequency": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Hourly",
-                        "name": "Hourly"
+            "type": "enum",
+            "members": {
+                "Hourly": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Hourly"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#RecurringChargesList": {
@@ -64361,6 +69045,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -64369,6 +69055,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnaSupport",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Set to <code>true</code> to enable enhanced networking with ENA for the AMI and any instances that you launch from the AMI.</p>\n         <p>This option is supported only for HVM AMIs. Specifying this option with a PV AMI can make instances launched from the AMI unreachable.</p>",
                         "smithy.api#xmlName": "enaSupport"
                     }
@@ -64385,6 +69073,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Name",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>A name for your AMI.</p>\n         <p>Constraints: 3-128 alphanumeric characters, parentheses (()), square brackets ([]), spaces ( ), periods (.), slashes (/), dashes (-), single quotes ('), at-signs (@), or underscores(_)</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "name"
@@ -64486,6 +69175,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -64516,6 +69207,8 @@
                 "IncludeAllTagsOfInstance": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to register all tag keys in the current Region. Specify <code>true</code> \n      \tto register all tag keys.</p>"
                     }
                 },
@@ -64567,6 +69260,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -64621,6 +69316,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -64675,6 +69372,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -64710,6 +69409,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway peering attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -64717,6 +69417,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -64753,6 +69455,7 @@
                 "TransitGatewayAttachmentId": {
                     "target": "com.amazonaws.ec2#TransitGatewayAttachmentId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the attachment.</p>",
                         "smithy.api#required": {}
                     }
@@ -64760,6 +69463,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -64796,12 +69501,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ServiceId": {
                     "target": "com.amazonaws.ec2#VpcEndpointServiceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the service.</p>",
                         "smithy.api#required": {}
                     }
@@ -64809,6 +69517,7 @@
                 "VpcEndpointIds": {
                     "target": "com.amazonaws.ec2#VpcEndpointIdList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of one or more VPC endpoints.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "VpcEndpointId"
@@ -64848,6 +69557,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -64856,6 +69567,7 @@
                     "target": "com.amazonaws.ec2#VpcPeeringConnectionId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcPeeringConnectionId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the VPC peering connection.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "vpcPeeringConnectionId"
@@ -64870,6 +69582,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -64913,6 +69627,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -64938,6 +69654,7 @@
                     "target": "com.amazonaws.ec2#RequestHostIdList",
                     "traits": {
                         "aws.protocols#ec2QueryName": "HostId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the Dedicated Hosts to release.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "hostId"
@@ -64984,12 +69701,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>A check for whether you have the required permissions for the action without actually making the request \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "IpamPoolId": {
                     "target": "com.amazonaws.ec2#IpamPoolId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the IPAM pool which contains the allocation you want to release.</p>",
                         "smithy.api#required": {}
                     }
@@ -64997,6 +69717,7 @@
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR of the allocation you want to release.</p>",
                         "smithy.api#required": {}
                     }
@@ -65004,6 +69725,7 @@
                 "IpamPoolAllocationId": {
                     "target": "com.amazonaws.ec2#IpamPoolAllocationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the allocation.</p>",
                         "smithy.api#required": {}
                     }
@@ -65017,6 +69739,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Success",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates if the release was successful.</p>",
                         "smithy.api#xmlName": "success"
                     }
@@ -65067,6 +69791,7 @@
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR block.</p>",
                         "smithy.api#required": {}
                     }
@@ -65094,6 +69819,7 @@
                 "IamInstanceProfile": {
                     "target": "com.amazonaws.ec2#IamInstanceProfileSpecification",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IAM instance profile.</p>",
                         "smithy.api#required": {}
                     }
@@ -65101,6 +69827,7 @@
                 "AssociationId": {
                     "target": "com.amazonaws.ec2#IamInstanceProfileAssociationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the existing IAM instance profile association.</p>",
                         "smithy.api#required": {}
                     }
@@ -65139,6 +69866,7 @@
                     "target": "com.amazonaws.ec2#NetworkAclAssociationId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AssociationId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the current association between the original network ACL and the subnet.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "associationId"
@@ -65148,6 +69876,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -65156,6 +69886,7 @@
                     "target": "com.amazonaws.ec2#NetworkAclId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkAclId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the new network ACL to associate with the subnet.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkAclId"
@@ -65203,6 +69934,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -65211,6 +69944,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Egress",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to replace the egress rule.</p>\n\t\t       <p>Default: If no value is specified, we replace the ingress rule.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "egress"
@@ -65235,6 +69970,7 @@
                     "target": "com.amazonaws.ec2#NetworkAclId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkAclId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the ACL.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkAclId"
@@ -65252,6 +69988,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Protocol",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The protocol number. A value of \"-1\" means all protocols. If you specify \"-1\" or a\n           protocol number other than \"6\" (TCP), \"17\" (UDP), or \"1\" (ICMP), traffic on all ports is \n           allowed, regardless of any ports or ICMP types or codes that you specify. If you specify \n           protocol \"58\" (ICMPv6) and specify an IPv4 CIDR block, traffic for all ICMP types and \n           codes allowed, regardless of any that you specify. If you specify protocol \"58\" (ICMPv6) \n           and specify an IPv6 CIDR block, you must specify an ICMP type and code.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "protocol"
@@ -65261,6 +69998,7 @@
                     "target": "com.amazonaws.ec2#RuleAction",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RuleAction",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Indicates whether to allow or deny the traffic that matches the rule.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ruleAction"
@@ -65270,6 +70008,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RuleNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The rule number of the entry to replace.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "ruleNumber"
@@ -65346,34 +70086,44 @@
             }
         },
         "com.amazonaws.ec2#ReplaceRootVolumeTaskState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "in-progress",
-                        "name": "in_progress"
-                    },
-                    {
-                        "value": "failing",
-                        "name": "failing"
-                    },
-                    {
-                        "value": "succeeded",
-                        "name": "succeeded"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
-                    },
-                    {
-                        "value": "failed-detached",
-                        "name": "failed_detached"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "in-progress"
+                    }
+                },
+                "failing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failing"
+                    }
+                },
+                "succeeded": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "succeeded"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "failed_detached": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed-detached"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ReplaceRootVolumeTasks": {
@@ -65426,6 +70176,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -65463,6 +70215,8 @@
                 "LocalTarget": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Specifies whether to reset the local route to its default target (<code>local</code>).</p>"
                     }
                 },
@@ -65504,6 +70258,7 @@
                     "target": "com.amazonaws.ec2#RouteTableId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RouteTableId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the route table.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "routeTableId"
@@ -65544,6 +70299,7 @@
                     "target": "com.amazonaws.ec2#RouteTableAssociationId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AssociationId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The association ID.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "associationId"
@@ -65553,6 +70309,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -65561,6 +70319,7 @@
                     "target": "com.amazonaws.ec2#RouteTableId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RouteTableId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the new route table to associate with the subnet.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "routeTableId"
@@ -65607,6 +70366,7 @@
                 "DestinationCidrBlock": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The CIDR range used for the destination match. Routing decisions are based on the most specific match.</p>",
                         "smithy.api#required": {}
                     }
@@ -65614,6 +70374,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -65627,12 +70388,16 @@
                 "Blackhole": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether traffic matching this route is to be dropped.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -65652,61 +70417,79 @@
             }
         },
         "com.amazonaws.ec2#ReplacementStrategy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "launch",
-                        "name": "LAUNCH"
-                    },
-                    {
-                        "value": "launch-before-terminate",
-                        "name": "LAUNCH_BEFORE_TERMINATE"
+            "type": "enum",
+            "members": {
+                "LAUNCH": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launch"
                     }
-                ]
+                },
+                "LAUNCH_BEFORE_TERMINATE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launch-before-terminate"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ReportInstanceReasonCodes": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "instance-stuck-in-state",
-                        "name": "instance_stuck_in_state"
-                    },
-                    {
-                        "value": "unresponsive",
-                        "name": "unresponsive"
-                    },
-                    {
-                        "value": "not-accepting-credentials",
-                        "name": "not_accepting_credentials"
-                    },
-                    {
-                        "value": "password-not-available",
-                        "name": "password_not_available"
-                    },
-                    {
-                        "value": "performance-network",
-                        "name": "performance_network"
-                    },
-                    {
-                        "value": "performance-instance-store",
-                        "name": "performance_instance_store"
-                    },
-                    {
-                        "value": "performance-ebs-volume",
-                        "name": "performance_ebs_volume"
-                    },
-                    {
-                        "value": "performance-other",
-                        "name": "performance_other"
-                    },
-                    {
-                        "value": "other",
-                        "name": "other"
+            "type": "enum",
+            "members": {
+                "instance_stuck_in_state": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instance-stuck-in-state"
                     }
-                ]
+                },
+                "unresponsive": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "unresponsive"
+                    }
+                },
+                "not_accepting_credentials": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "not-accepting-credentials"
+                    }
+                },
+                "password_not_available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "password-not-available"
+                    }
+                },
+                "performance_network": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "performance-network"
+                    }
+                },
+                "performance_instance_store": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "performance-instance-store"
+                    }
+                },
+                "performance_ebs_volume": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "performance-ebs-volume"
+                    }
+                },
+                "performance_other": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "performance-other"
+                    }
+                },
+                "other": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "other"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ReportInstanceStatus": {
@@ -65736,6 +70519,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -65752,6 +70537,7 @@
                     "target": "com.amazonaws.ec2#InstanceIdStringList",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The instances.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "instanceId"
@@ -65761,6 +70547,7 @@
                     "target": "com.amazonaws.ec2#ReasonCodesList",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ReasonCode",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The reason codes that describe the health state of your instance.</p>\n        <ul>\n            <li>\n                <p>\n                    <code>instance-stuck-in-state</code>: My instance is stuck in a state.</p>\n            </li>\n            <li>\n                <p>\n                    <code>unresponsive</code>: My instance is unresponsive.</p>\n            </li>\n            <li>\n                <p>\n                    <code>not-accepting-credentials</code>: My instance is not accepting my\n                    credentials.</p>\n            </li>\n            <li>\n                <p>\n                    <code>password-not-available</code>: A password is not available for my\n                    instance.</p>\n            </li>\n            <li>\n                <p>\n                    <code>performance-network</code>: My instance is experiencing performance\n                    problems that I believe are network related.</p>\n            </li>\n            <li>\n                <p>\n                    <code>performance-instance-store</code>: My instance is experiencing performance\n                    problems that I believe are related to the instance stores.</p>\n            </li>\n            <li>\n                <p>\n                    <code>performance-ebs-volume</code>: My instance is experiencing performance\n                    problems that I believe are related to an EBS volume.</p>\n            </li>\n            <li>\n                <p>\n                    <code>performance-other</code>: My instance is experiencing performance\n                    problems.</p>\n            </li>\n            <li>\n                <p>\n                    <code>other</code>: [explain using the description parameter]</p>\n            </li>\n         </ul>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "reasonCode"
@@ -65778,6 +70565,7 @@
                     "target": "com.amazonaws.ec2#ReportStatusType",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Status",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The status of all instances listed.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "status"
@@ -65786,18 +70574,20 @@
             }
         },
         "com.amazonaws.ec2#ReportStatusType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ok",
-                        "name": "ok"
-                    },
-                    {
-                        "value": "impaired",
-                        "name": "impaired"
+            "type": "enum",
+            "members": {
+                "ok": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ok"
                     }
-                ]
+                },
+                "impaired": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "impaired"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#RequestHostIdList": {
@@ -65871,6 +70661,8 @@
                 "EbsOptimized": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the instance is optimized for Amazon EBS I/O. This optimization\n            provides dedicated throughput to Amazon EBS and an optimized configuration stack to\n            provide optimal Amazon EBS I/O performance. This optimization isn't available with all\n            instance types. Additional usage charges apply when using an EBS-optimized\n            instance.</p>"
                     }
                 },
@@ -65933,6 +70725,8 @@
                 "DisableApiTermination": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If you set this parameter to <code>true</code>, you can't terminate the instance using\n            the Amazon EC2 console, CLI, or API; otherwise, you can. To change this attribute after\n            launch, use <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_ModifyInstanceAttribute.html\">ModifyInstanceAttribute</a>. Alternatively, if you set\n                <code>InstanceInitiatedShutdownBehavior</code> to <code>terminate</code>, you can\n            terminate the instance by running the shutdown command from the instance.</p>"
                     }
                 },
@@ -66053,6 +70847,8 @@
                 "DisableApiStop": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to enable the instance for stop protection. For more information,\n            see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Stop_Start.html#Using_StopProtection\">Stop\n                Protection</a>.</p>"
                     }
                 }
@@ -66081,6 +70877,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -66089,6 +70887,7 @@
                     "target": "com.amazonaws.ec2#SpotFleetRequestConfigData",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SpotFleetRequestConfig",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The configuration for the Spot Fleet request.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "spotFleetRequestConfig"
@@ -66142,6 +70941,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "BlockDurationMinutes",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>Deprecated.</p>",
                         "smithy.api#xmlName": "blockDurationMinutes"
                     }
@@ -66158,6 +70959,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually\n            making the request, and provides an error response. If you have the required\n            permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is\n                <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -66166,6 +70969,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of Spot Instances to launch.</p>\n        <p>Default: 1</p>",
                         "smithy.api#xmlName": "instanceCount"
                     }
@@ -66287,6 +71092,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EbsOptimized",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the instance is optimized for EBS I/O. This optimization provides dedicated throughput to Amazon EBS and an optimized configuration stack to provide optimal EBS I/O performance. This optimization isn't available with all instance types. Additional usage charges apply when using an EBS Optimized instance.</p>\n         <p>Default: <code>false</code>\n         </p>",
                         "smithy.api#xmlName": "ebsOptimized"
                     }
@@ -66485,6 +71292,8 @@
                 "EbsOptimized": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the Capacity Reservation Fleet supports EBS-optimized instances types. This \n\t\t\toptimization provides dedicated throughput to Amazon EBS and an optimized configuration stack \n\t\t\tto provide optimal I/O performance. This optimization isn't available with all instance types. Additional \n\t\t\tusage charges apply when using EBS-optimized instance types.</p>"
                     }
                 },
@@ -66518,26 +71327,32 @@
             }
         },
         "com.amazonaws.ec2#ReservationState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "payment-pending",
-                        "name": "PAYMENT_PENDING"
-                    },
-                    {
-                        "value": "payment-failed",
-                        "name": "PAYMENT_FAILED"
-                    },
-                    {
-                        "value": "active",
-                        "name": "ACTIVE"
-                    },
-                    {
-                        "value": "retired",
-                        "name": "RETIRED"
+            "type": "enum",
+            "members": {
+                "PAYMENT_PENDING": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "payment-pending"
                     }
-                ]
+                },
+                "PAYMENT_FAILED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "payment-failed"
+                    }
+                },
+                "ACTIVE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "RETIRED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "retired"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ReservationValue": {
@@ -66588,6 +71403,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Amount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>Used for Reserved Instance Marketplace offerings. Specifies the limit price on the total order (instanceCount * price).</p>",
                         "smithy.api#xmlName": "amount"
                     }
@@ -66639,34 +71456,44 @@
             }
         },
         "com.amazonaws.ec2#ReservedInstanceState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "payment-pending",
-                        "name": "payment_pending"
-                    },
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "payment-failed",
-                        "name": "payment_failed"
-                    },
-                    {
-                        "value": "retired",
-                        "name": "retired"
-                    },
-                    {
-                        "value": "queued",
-                        "name": "queued"
-                    },
-                    {
-                        "value": "queued-deleted",
-                        "name": "queued_deleted"
+            "type": "enum",
+            "members": {
+                "payment_pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "payment-pending"
                     }
-                ]
+                },
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "payment_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "payment-failed"
+                    }
+                },
+                "retired": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "retired"
+                    }
+                },
+                "queued": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "queued"
+                    }
+                },
+                "queued_deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "queued-deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ReservedInstances": {
@@ -66684,6 +71511,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Duration",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The duration of the Reserved Instance, in seconds.</p>",
                         "smithy.api#xmlName": "duration"
                     }
@@ -66700,6 +71529,8 @@
                     "target": "com.amazonaws.ec2#Float",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FixedPrice",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The purchase price of the Reserved Instance.</p>",
                         "smithy.api#xmlName": "fixedPrice"
                     }
@@ -66708,6 +71539,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of reservations purchased.</p>",
                         "smithy.api#xmlName": "instanceCount"
                     }
@@ -66756,6 +71589,8 @@
                     "target": "com.amazonaws.ec2#Float",
                     "traits": {
                         "aws.protocols#ec2QueryName": "UsagePrice",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The usage price of the Reserved Instance, per hour.</p>",
                         "smithy.api#xmlName": "usagePrice"
                     }
@@ -66836,6 +71671,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of modified Reserved Instances.</p>\n         <note>\n            <p>This is a required field for a request.</p>\n         </note>",
                         "smithy.api#xmlName": "instanceCount"
                     }
@@ -67161,6 +71998,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Duration",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The duration of the Reserved Instance, in seconds.</p>",
                         "smithy.api#xmlName": "duration"
                     }
@@ -67169,6 +72008,8 @@
                     "target": "com.amazonaws.ec2#Float",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FixedPrice",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The purchase price of the Reserved Instance.</p>",
                         "smithy.api#xmlName": "fixedPrice"
                     }
@@ -67201,6 +72042,8 @@
                     "target": "com.amazonaws.ec2#Float",
                     "traits": {
                         "aws.protocols#ec2QueryName": "UsagePrice",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The usage price of the Reserved Instance, per hour.</p>",
                         "smithy.api#xmlName": "usagePrice"
                     }
@@ -67225,6 +72068,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Marketplace",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the offering is available through the Reserved Instance Marketplace (resale) or Amazon Web Services. \n        If it's a Reserved Instance Marketplace offering, this is <code>true</code>.</p>",
                         "smithy.api#xmlName": "marketplace"
                     }
@@ -67319,6 +72164,7 @@
                 "AllocationId": {
                     "target": "com.amazonaws.ec2#AllocationId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>[EC2-VPC] The allocation ID.</p>",
                         "smithy.api#required": {}
                     }
@@ -67326,6 +72172,7 @@
                 "Attribute": {
                     "target": "com.amazonaws.ec2#AddressAttributeName",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The attribute of the IP address.</p>",
                         "smithy.api#required": {}
                     }
@@ -67333,6 +72180,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -67369,6 +72218,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -67400,14 +72251,14 @@
             }
         },
         "com.amazonaws.ec2#ResetFpgaImageAttributeName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "loadPermission",
-                        "name": "loadPermission"
+            "type": "enum",
+            "members": {
+                "loadPermission": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "loadPermission"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#ResetFpgaImageAttributeRequest": {
@@ -67416,12 +72267,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "FpgaImageId": {
                     "target": "com.amazonaws.ec2#FpgaImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AFI.</p>",
                         "smithy.api#required": {}
                     }
@@ -67441,6 +72295,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Is <code>true</code> if the request succeeds, and an error otherwise.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -67460,14 +72316,14 @@
             }
         },
         "com.amazonaws.ec2#ResetImageAttributeName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "launchPermission",
-                        "name": "launchPermission"
+            "type": "enum",
+            "members": {
+                "launchPermission": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launchPermission"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#ResetImageAttributeRequest": {
@@ -67476,6 +72332,7 @@
                 "Attribute": {
                     "target": "com.amazonaws.ec2#ResetImageAttributeName",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The attribute to reset (currently you can only reset the launch permission attribute).</p>",
                         "smithy.api#required": {}
                     }
@@ -67483,6 +72340,7 @@
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AMI.</p>",
                         "smithy.api#required": {}
                     }
@@ -67491,6 +72349,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -67519,6 +72379,7 @@
                     "target": "com.amazonaws.ec2#InstanceAttributeName",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Attribute",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The attribute to reset.</p>\n        <important>\n            <p>You can only reset the following attributes: <code>kernel</code> |\n                    <code>ramdisk</code> | <code>sourceDestCheck</code>.</p>\n        </important>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "attribute"
@@ -67528,480 +72389,650 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
+                        "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
+                        "smithy.api#xmlName": "dryRun"
+                    }
+                },
+                "InstanceId": {
+                    "target": "com.amazonaws.ec2#InstanceId",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "InstanceId",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#documentation": "<p>The ID of the instance.</p>",
+                        "smithy.api#required": {},
+                        "smithy.api#xmlName": "instanceId"
+                    }
+                }
+            }
+        },
+        "com.amazonaws.ec2#ResetNetworkInterfaceAttribute": {
+            "type": "operation",
+            "input": {
+                "target": "com.amazonaws.ec2#ResetNetworkInterfaceAttributeRequest"
+            },
+            "output": {
+                "target": "smithy.api#Unit"
+            },
+            "traits": {
+                "smithy.api#documentation": "<p>Resets a network interface attribute. You can specify only one attribute at a time.</p>"
+            }
+        },
+        "com.amazonaws.ec2#ResetNetworkInterfaceAttributeRequest": {
+            "type": "structure",
+            "members": {
+                "DryRun": {
+                    "target": "com.amazonaws.ec2#Boolean",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
+                        "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n            and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n            Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
+                        "smithy.api#xmlName": "dryRun"
+                    }
+                },
+                "NetworkInterfaceId": {
+                    "target": "com.amazonaws.ec2#NetworkInterfaceId",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "NetworkInterfaceId",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#documentation": "<p>The ID of the network interface.</p>",
+                        "smithy.api#required": {},
+                        "smithy.api#xmlName": "networkInterfaceId"
+                    }
+                },
+                "SourceDestCheck": {
+                    "target": "com.amazonaws.ec2#String",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "SourceDestCheck",
+                        "smithy.api#documentation": "<p>The source/destination checking attribute. Resets the value to <code>true</code>.</p>",
+                        "smithy.api#xmlName": "sourceDestCheck"
+                    }
+                }
+            },
+            "traits": {
+                "smithy.api#documentation": "<p>Contains the parameters for ResetNetworkInterfaceAttribute.</p>"
+            }
+        },
+        "com.amazonaws.ec2#ResetSnapshotAttribute": {
+            "type": "operation",
+            "input": {
+                "target": "com.amazonaws.ec2#ResetSnapshotAttributeRequest"
+            },
+            "output": {
+                "target": "smithy.api#Unit"
+            },
+            "traits": {
+                "smithy.api#documentation": "<p>Resets permission settings for the specified snapshot.</p>\n         <p>For more information about modifying snapshot permissions, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-modifying-snapshot-permissions.html\">Share a snapshot</a> in the\n        <i>Amazon Elastic Compute Cloud User Guide</i>.</p>"
+            }
+        },
+        "com.amazonaws.ec2#ResetSnapshotAttributeRequest": {
+            "type": "structure",
+            "members": {
+                "Attribute": {
+                    "target": "com.amazonaws.ec2#SnapshotAttributeName",
+                    "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#documentation": "<p>The attribute to reset. Currently, only the attribute for permission to create volumes can\n      be reset.</p>",
+                        "smithy.api#required": {}
+                    }
+                },
+                "SnapshotId": {
+                    "target": "com.amazonaws.ec2#SnapshotId",
+                    "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#documentation": "<p>The ID of the snapshot.</p>",
+                        "smithy.api#required": {}
+                    }
+                },
+                "DryRun": {
+                    "target": "com.amazonaws.ec2#Boolean",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
+                }
+            }
+        },
+        "com.amazonaws.ec2#ResourceArn": {
+            "type": "string",
+            "traits": {
+                "smithy.api#length": {
+                    "min": 1,
+                    "max": 1283
+                }
+            }
+        },
+        "com.amazonaws.ec2#ResourceIdList": {
+            "type": "list",
+            "member": {
+                "target": "com.amazonaws.ec2#TaggableResourceId"
+            }
+        },
+        "com.amazonaws.ec2#ResourceList": {
+            "type": "list",
+            "member": {
+                "target": "com.amazonaws.ec2#String",
+                "traits": {
+                    "smithy.api#xmlName": "item"
+                }
+            }
+        },
+        "com.amazonaws.ec2#ResourceStatement": {
+            "type": "structure",
+            "members": {
+                "Resources": {
+                    "target": "com.amazonaws.ec2#ValueStringList",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "ResourceSet",
+                        "smithy.api#documentation": "<p>The resources.</p>",
+                        "smithy.api#xmlName": "resourceSet"
+                    }
+                },
+                "ResourceTypes": {
+                    "target": "com.amazonaws.ec2#ValueStringList",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "ResourceTypeSet",
+                        "smithy.api#documentation": "<p>The resource types.</p>",
+                        "smithy.api#xmlName": "resourceTypeSet"
+                    }
+                }
+            },
+            "traits": {
+                "smithy.api#documentation": "<p>Describes a resource statement.</p>"
+            }
+        },
+        "com.amazonaws.ec2#ResourceStatementRequest": {
+            "type": "structure",
+            "members": {
+                "Resources": {
+                    "target": "com.amazonaws.ec2#ValueStringList",
+                    "traits": {
+                        "smithy.api#documentation": "<p>The resources.</p>",
+                        "smithy.api#xmlName": "Resource"
+                    }
+                },
+                "ResourceTypes": {
+                    "target": "com.amazonaws.ec2#ValueStringList",
+                    "traits": {
+                        "smithy.api#documentation": "<p>The resource types.</p>",
+                        "smithy.api#xmlName": "ResourceType"
+                    }
+                }
+            },
+            "traits": {
+                "smithy.api#documentation": "<p>Describes a resource statement.</p>"
+            }
+        },
+        "com.amazonaws.ec2#ResourceType": {
+            "type": "enum",
+            "members": {
+                "capacity_reservation": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "capacity-reservation"
+                    }
+                },
+                "client_vpn_endpoint": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "client-vpn-endpoint"
+                    }
+                },
+                "customer_gateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "customer-gateway"
+                    }
+                },
+                "carrier_gateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "carrier-gateway"
+                    }
+                },
+                "coip_pool": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "coip-pool"
+                    }
+                },
+                "dedicated_host": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "dedicated-host"
+                    }
+                },
+                "dhcp_options": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "dhcp-options"
+                    }
+                },
+                "egress_only_internet_gateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "egress-only-internet-gateway"
+                    }
+                },
+                "elastic_ip": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "elastic-ip"
+                    }
+                },
+                "elastic_gpu": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "elastic-gpu"
+                    }
+                },
+                "export_image_task": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "export-image-task"
+                    }
+                },
+                "export_instance_task": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "export-instance-task"
+                    }
+                },
+                "fleet": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fleet"
+                    }
+                },
+                "fpga_image": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "fpga-image"
+                    }
+                },
+                "host_reservation": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "host-reservation"
+                    }
+                },
+                "image": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "image"
+                    }
+                },
+                "import_image_task": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "import-image-task"
+                    }
+                },
+                "import_snapshot_task": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "import-snapshot-task"
+                    }
+                },
+                "instance": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instance"
+                    }
+                },
+                "instance_event_window": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instance-event-window"
+                    }
+                },
+                "internet_gateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "internet-gateway"
+                    }
+                },
+                "ipam": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipam"
+                    }
+                },
+                "ipam_pool": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipam-pool"
+                    }
+                },
+                "ipam_scope": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipam-scope"
+                    }
+                },
+                "ipv4pool_ec2": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv4pool-ec2"
+                    }
+                },
+                "ipv6pool_ec2": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv6pool-ec2"
+                    }
+                },
+                "key_pair": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "key-pair"
+                    }
+                },
+                "launch_template": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "launch-template"
+                    }
+                },
+                "local_gateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "local-gateway"
+                    }
+                },
+                "local_gateway_route_table": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "local-gateway-route-table"
+                    }
+                },
+                "local_gateway_virtual_interface": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "local-gateway-virtual-interface"
+                    }
+                },
+                "local_gateway_virtual_interface_group": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "local-gateway-virtual-interface-group"
+                    }
+                },
+                "local_gateway_route_table_vpc_association": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "local-gateway-route-table-vpc-association"
+                    }
+                },
+                "local_gateway_route_table_virtual_interface_group_association": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "local-gateway-route-table-virtual-interface-group-association"
+                    }
+                },
+                "natgateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "natgateway"
+                    }
+                },
+                "network_acl": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "network-acl"
+                    }
+                },
+                "network_interface": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "network-interface"
+                    }
+                },
+                "network_insights_analysis": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "network-insights-analysis"
+                    }
+                },
+                "network_insights_path": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "network-insights-path"
+                    }
+                },
+                "network_insights_access_scope": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "network-insights-access-scope"
+                    }
+                },
+                "network_insights_access_scope_analysis": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "network-insights-access-scope-analysis"
+                    }
+                },
+                "placement_group": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "placement-group"
+                    }
+                },
+                "prefix_list": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "prefix-list"
+                    }
+                },
+                "replace_root_volume_task": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "replace-root-volume-task"
+                    }
+                },
+                "reserved_instances": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "reserved-instances"
+                    }
+                },
+                "route_table": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "route-table"
+                    }
+                },
+                "security_group": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "security-group"
+                    }
+                },
+                "security_group_rule": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "security-group-rule"
+                    }
+                },
+                "snapshot": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "snapshot"
+                    }
+                },
+                "spot_fleet_request": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "spot-fleet-request"
+                    }
+                },
+                "spot_instances_request": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "spot-instances-request"
+                    }
+                },
+                "subnet": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "subnet"
+                    }
+                },
+                "subnet_cidr_reservation": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "subnet-cidr-reservation"
+                    }
+                },
+                "traffic_mirror_filter": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "traffic-mirror-filter"
+                    }
+                },
+                "traffic_mirror_session": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "traffic-mirror-session"
+                    }
+                },
+                "traffic_mirror_target": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "traffic-mirror-target"
+                    }
+                },
+                "transit_gateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "transit-gateway"
+                    }
+                },
+                "transit_gateway_attachment": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "transit-gateway-attachment"
+                    }
+                },
+                "transit_gateway_connect_peer": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "transit-gateway-connect-peer"
+                    }
+                },
+                "transit_gateway_multicast_domain": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "transit-gateway-multicast-domain"
+                    }
+                },
+                "transit_gateway_policy_table": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "transit-gateway-policy-table"
+                    }
+                },
+                "transit_gateway_route_table": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "transit-gateway-route-table"
+                    }
+                },
+                "transit_gateway_route_table_announcement": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "transit-gateway-route-table-announcement"
+                    }
+                },
+                "volume": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "volume"
+                    }
+                },
+                "vpc": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vpc"
+                    }
+                },
+                "vpc_endpoint": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vpc-endpoint"
+                    }
                 },
-                "InstanceId": {
-                    "target": "com.amazonaws.ec2#InstanceId",
+                "vpc_endpoint_connection": {
+                    "target": "smithy.api#Unit",
                     "traits": {
-                        "aws.protocols#ec2QueryName": "InstanceId",
-                        "smithy.api#documentation": "<p>The ID of the instance.</p>",
-                        "smithy.api#required": {},
-                        "smithy.api#xmlName": "instanceId"
+                        "smithy.api#enumValue": "vpc-endpoint-connection"
                     }
-                }
-            }
-        },
-        "com.amazonaws.ec2#ResetNetworkInterfaceAttribute": {
-            "type": "operation",
-            "input": {
-                "target": "com.amazonaws.ec2#ResetNetworkInterfaceAttributeRequest"
-            },
-            "output": {
-                "target": "smithy.api#Unit"
-            },
-            "traits": {
-                "smithy.api#documentation": "<p>Resets a network interface attribute. You can specify only one attribute at a time.</p>"
-            }
-        },
-        "com.amazonaws.ec2#ResetNetworkInterfaceAttributeRequest": {
-            "type": "structure",
-            "members": {
-                "DryRun": {
-                    "target": "com.amazonaws.ec2#Boolean",
+                },
+                "vpc_endpoint_service": {
+                    "target": "smithy.api#Unit",
                     "traits": {
-                        "aws.protocols#ec2QueryName": "DryRun",
-                        "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n            and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n            Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
-                        "smithy.api#xmlName": "dryRun"
+                        "smithy.api#enumValue": "vpc-endpoint-service"
                     }
                 },
-                "NetworkInterfaceId": {
-                    "target": "com.amazonaws.ec2#NetworkInterfaceId",
+                "vpc_endpoint_service_permission": {
+                    "target": "smithy.api#Unit",
                     "traits": {
-                        "aws.protocols#ec2QueryName": "NetworkInterfaceId",
-                        "smithy.api#documentation": "<p>The ID of the network interface.</p>",
-                        "smithy.api#required": {},
-                        "smithy.api#xmlName": "networkInterfaceId"
+                        "smithy.api#enumValue": "vpc-endpoint-service-permission"
                     }
                 },
-                "SourceDestCheck": {
-                    "target": "com.amazonaws.ec2#String",
+                "vpc_peering_connection": {
+                    "target": "smithy.api#Unit",
                     "traits": {
-                        "aws.protocols#ec2QueryName": "SourceDestCheck",
-                        "smithy.api#documentation": "<p>The source/destination checking attribute. Resets the value to <code>true</code>.</p>",
-                        "smithy.api#xmlName": "sourceDestCheck"
+                        "smithy.api#enumValue": "vpc-peering-connection"
                     }
-                }
-            },
-            "traits": {
-                "smithy.api#documentation": "<p>Contains the parameters for ResetNetworkInterfaceAttribute.</p>"
-            }
-        },
-        "com.amazonaws.ec2#ResetSnapshotAttribute": {
-            "type": "operation",
-            "input": {
-                "target": "com.amazonaws.ec2#ResetSnapshotAttributeRequest"
-            },
-            "output": {
-                "target": "smithy.api#Unit"
-            },
-            "traits": {
-                "smithy.api#documentation": "<p>Resets permission settings for the specified snapshot.</p>\n         <p>For more information about modifying snapshot permissions, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-modifying-snapshot-permissions.html\">Share a snapshot</a> in the\n        <i>Amazon Elastic Compute Cloud User Guide</i>.</p>"
-            }
-        },
-        "com.amazonaws.ec2#ResetSnapshotAttributeRequest": {
-            "type": "structure",
-            "members": {
-                "Attribute": {
-                    "target": "com.amazonaws.ec2#SnapshotAttributeName",
+                },
+                "vpn_connection": {
+                    "target": "smithy.api#Unit",
                     "traits": {
-                        "smithy.api#documentation": "<p>The attribute to reset. Currently, only the attribute for permission to create volumes can\n      be reset.</p>",
-                        "smithy.api#required": {}
+                        "smithy.api#enumValue": "vpn-connection"
                     }
                 },
-                "SnapshotId": {
-                    "target": "com.amazonaws.ec2#SnapshotId",
+                "vpn_gateway": {
+                    "target": "smithy.api#Unit",
                     "traits": {
-                        "smithy.api#documentation": "<p>The ID of the snapshot.</p>",
-                        "smithy.api#required": {}
+                        "smithy.api#enumValue": "vpn-gateway"
                     }
                 },
-                "DryRun": {
-                    "target": "com.amazonaws.ec2#Boolean",
+                "vpc_flow_log": {
+                    "target": "smithy.api#Unit",
                     "traits": {
-                        "aws.protocols#ec2QueryName": "DryRun",
-                        "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
-                        "smithy.api#xmlName": "dryRun"
+                        "smithy.api#enumValue": "vpc-flow-log"
                     }
-                }
-            }
-        },
-        "com.amazonaws.ec2#ResourceArn": {
-            "type": "string",
-            "traits": {
-                "smithy.api#length": {
-                    "min": 1,
-                    "max": 1283
-                }
-            }
-        },
-        "com.amazonaws.ec2#ResourceIdList": {
-            "type": "list",
-            "member": {
-                "target": "com.amazonaws.ec2#TaggableResourceId"
-            }
-        },
-        "com.amazonaws.ec2#ResourceList": {
-            "type": "list",
-            "member": {
-                "target": "com.amazonaws.ec2#String",
-                "traits": {
-                    "smithy.api#xmlName": "item"
-                }
-            }
-        },
-        "com.amazonaws.ec2#ResourceStatement": {
-            "type": "structure",
-            "members": {
-                "Resources": {
-                    "target": "com.amazonaws.ec2#ValueStringList",
+                },
+                "capacity_reservation_fleet": {
+                    "target": "smithy.api#Unit",
                     "traits": {
-                        "aws.protocols#ec2QueryName": "ResourceSet",
-                        "smithy.api#documentation": "<p>The resources.</p>",
-                        "smithy.api#xmlName": "resourceSet"
+                        "smithy.api#enumValue": "capacity-reservation-fleet"
                     }
                 },
-                "ResourceTypes": {
-                    "target": "com.amazonaws.ec2#ValueStringList",
+                "traffic_mirror_filter_rule": {
+                    "target": "smithy.api#Unit",
                     "traits": {
-                        "aws.protocols#ec2QueryName": "ResourceTypeSet",
-                        "smithy.api#documentation": "<p>The resource types.</p>",
-                        "smithy.api#xmlName": "resourceTypeSet"
+                        "smithy.api#enumValue": "traffic-mirror-filter-rule"
                     }
-                }
-            },
-            "traits": {
-                "smithy.api#documentation": "<p>Describes a resource statement.</p>"
-            }
-        },
-        "com.amazonaws.ec2#ResourceStatementRequest": {
-            "type": "structure",
-            "members": {
-                "Resources": {
-                    "target": "com.amazonaws.ec2#ValueStringList",
+                },
+                "vpc_endpoint_connection_device_type": {
+                    "target": "smithy.api#Unit",
                     "traits": {
-                        "smithy.api#documentation": "<p>The resources.</p>",
-                        "smithy.api#xmlName": "Resource"
+                        "smithy.api#enumValue": "vpc-endpoint-connection-device-type"
                     }
                 },
-                "ResourceTypes": {
-                    "target": "com.amazonaws.ec2#ValueStringList",
+                "vpn_connection_device_type": {
+                    "target": "smithy.api#Unit",
                     "traits": {
-                        "smithy.api#documentation": "<p>The resource types.</p>",
-                        "smithy.api#xmlName": "ResourceType"
+                        "smithy.api#enumValue": "vpn-connection-device-type"
                     }
                 }
-            },
-            "traits": {
-                "smithy.api#documentation": "<p>Describes a resource statement.</p>"
-            }
-        },
-        "com.amazonaws.ec2#ResourceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "capacity-reservation",
-                        "name": "capacity_reservation"
-                    },
-                    {
-                        "value": "client-vpn-endpoint",
-                        "name": "client_vpn_endpoint"
-                    },
-                    {
-                        "value": "customer-gateway",
-                        "name": "customer_gateway"
-                    },
-                    {
-                        "value": "carrier-gateway",
-                        "name": "carrier_gateway"
-                    },
-                    {
-                        "value": "coip-pool",
-                        "name": "coip_pool"
-                    },
-                    {
-                        "value": "dedicated-host",
-                        "name": "dedicated_host"
-                    },
-                    {
-                        "value": "dhcp-options",
-                        "name": "dhcp_options"
-                    },
-                    {
-                        "value": "egress-only-internet-gateway",
-                        "name": "egress_only_internet_gateway"
-                    },
-                    {
-                        "value": "elastic-ip",
-                        "name": "elastic_ip"
-                    },
-                    {
-                        "value": "elastic-gpu",
-                        "name": "elastic_gpu"
-                    },
-                    {
-                        "value": "export-image-task",
-                        "name": "export_image_task"
-                    },
-                    {
-                        "value": "export-instance-task",
-                        "name": "export_instance_task"
-                    },
-                    {
-                        "value": "fleet",
-                        "name": "fleet"
-                    },
-                    {
-                        "value": "fpga-image",
-                        "name": "fpga_image"
-                    },
-                    {
-                        "value": "host-reservation",
-                        "name": "host_reservation"
-                    },
-                    {
-                        "value": "image",
-                        "name": "image"
-                    },
-                    {
-                        "value": "import-image-task",
-                        "name": "import_image_task"
-                    },
-                    {
-                        "value": "import-snapshot-task",
-                        "name": "import_snapshot_task"
-                    },
-                    {
-                        "value": "instance",
-                        "name": "instance"
-                    },
-                    {
-                        "value": "instance-event-window",
-                        "name": "instance_event_window"
-                    },
-                    {
-                        "value": "internet-gateway",
-                        "name": "internet_gateway"
-                    },
-                    {
-                        "value": "ipam",
-                        "name": "ipam"
-                    },
-                    {
-                        "value": "ipam-pool",
-                        "name": "ipam_pool"
-                    },
-                    {
-                        "value": "ipam-scope",
-                        "name": "ipam_scope"
-                    },
-                    {
-                        "value": "ipv4pool-ec2",
-                        "name": "ipv4pool_ec2"
-                    },
-                    {
-                        "value": "ipv6pool-ec2",
-                        "name": "ipv6pool_ec2"
-                    },
-                    {
-                        "value": "key-pair",
-                        "name": "key_pair"
-                    },
-                    {
-                        "value": "launch-template",
-                        "name": "launch_template"
-                    },
-                    {
-                        "value": "local-gateway",
-                        "name": "local_gateway"
-                    },
-                    {
-                        "value": "local-gateway-route-table",
-                        "name": "local_gateway_route_table"
-                    },
-                    {
-                        "value": "local-gateway-virtual-interface",
-                        "name": "local_gateway_virtual_interface"
-                    },
-                    {
-                        "value": "local-gateway-virtual-interface-group",
-                        "name": "local_gateway_virtual_interface_group"
-                    },
-                    {
-                        "value": "local-gateway-route-table-vpc-association",
-                        "name": "local_gateway_route_table_vpc_association"
-                    },
-                    {
-                        "value": "local-gateway-route-table-virtual-interface-group-association",
-                        "name": "local_gateway_route_table_virtual_interface_group_association"
-                    },
-                    {
-                        "value": "natgateway",
-                        "name": "natgateway"
-                    },
-                    {
-                        "value": "network-acl",
-                        "name": "network_acl"
-                    },
-                    {
-                        "value": "network-interface",
-                        "name": "network_interface"
-                    },
-                    {
-                        "value": "network-insights-analysis",
-                        "name": "network_insights_analysis"
-                    },
-                    {
-                        "value": "network-insights-path",
-                        "name": "network_insights_path"
-                    },
-                    {
-                        "value": "network-insights-access-scope",
-                        "name": "network_insights_access_scope"
-                    },
-                    {
-                        "value": "network-insights-access-scope-analysis",
-                        "name": "network_insights_access_scope_analysis"
-                    },
-                    {
-                        "value": "placement-group",
-                        "name": "placement_group"
-                    },
-                    {
-                        "value": "prefix-list",
-                        "name": "prefix_list"
-                    },
-                    {
-                        "value": "replace-root-volume-task",
-                        "name": "replace_root_volume_task"
-                    },
-                    {
-                        "value": "reserved-instances",
-                        "name": "reserved_instances"
-                    },
-                    {
-                        "value": "route-table",
-                        "name": "route_table"
-                    },
-                    {
-                        "value": "security-group",
-                        "name": "security_group"
-                    },
-                    {
-                        "value": "security-group-rule",
-                        "name": "security_group_rule"
-                    },
-                    {
-                        "value": "snapshot",
-                        "name": "snapshot"
-                    },
-                    {
-                        "value": "spot-fleet-request",
-                        "name": "spot_fleet_request"
-                    },
-                    {
-                        "value": "spot-instances-request",
-                        "name": "spot_instances_request"
-                    },
-                    {
-                        "value": "subnet",
-                        "name": "subnet"
-                    },
-                    {
-                        "value": "subnet-cidr-reservation",
-                        "name": "subnet_cidr_reservation"
-                    },
-                    {
-                        "value": "traffic-mirror-filter",
-                        "name": "traffic_mirror_filter"
-                    },
-                    {
-                        "value": "traffic-mirror-session",
-                        "name": "traffic_mirror_session"
-                    },
-                    {
-                        "value": "traffic-mirror-target",
-                        "name": "traffic_mirror_target"
-                    },
-                    {
-                        "value": "transit-gateway",
-                        "name": "transit_gateway"
-                    },
-                    {
-                        "value": "transit-gateway-attachment",
-                        "name": "transit_gateway_attachment"
-                    },
-                    {
-                        "value": "transit-gateway-connect-peer",
-                        "name": "transit_gateway_connect_peer"
-                    },
-                    {
-                        "value": "transit-gateway-multicast-domain",
-                        "name": "transit_gateway_multicast_domain"
-                    },
-                    {
-                        "value": "transit-gateway-policy-table",
-                        "name": "transit_gateway_policy_table"
-                    },
-                    {
-                        "value": "transit-gateway-route-table",
-                        "name": "transit_gateway_route_table"
-                    },
-                    {
-                        "value": "transit-gateway-route-table-announcement",
-                        "name": "transit_gateway_route_table_announcement"
-                    },
-                    {
-                        "value": "volume",
-                        "name": "volume"
-                    },
-                    {
-                        "value": "vpc",
-                        "name": "vpc"
-                    },
-                    {
-                        "value": "vpc-endpoint",
-                        "name": "vpc_endpoint"
-                    },
-                    {
-                        "value": "vpc-endpoint-service",
-                        "name": "vpc_endpoint_service"
-                    },
-                    {
-                        "value": "vpc-peering-connection",
-                        "name": "vpc_peering_connection"
-                    },
-                    {
-                        "value": "vpn-connection",
-                        "name": "vpn_connection"
-                    },
-                    {
-                        "value": "vpn-gateway",
-                        "name": "vpn_gateway"
-                    },
-                    {
-                        "value": "vpc-flow-log",
-                        "name": "vpc_flow_log"
-                    },
-                    {
-                        "value": "capacity-reservation-fleet",
-                        "name": "capacity_reservation_fleet"
-                    },
-                    {
-                        "value": "traffic-mirror-filter-rule",
-                        "name": "traffic_mirror_filter_rule"
-                    },
-                    {
-                        "value": "vpc-endpoint-connection-device-type",
-                        "name": "vpc_endpoint_connection_device_type"
-                    },
-                    {
-                        "value": "vpn-connection-device-type",
-                        "name": "vpn_connection_device_type"
-                    }
-                ]
             }
         },
         "com.amazonaws.ec2#ResponseError": {
@@ -68061,6 +73092,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EbsOptimized",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the instance is optimized for Amazon EBS I/O. </p>",
                         "smithy.api#xmlName": "ebsOptimized"
                     }
@@ -68141,6 +73174,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DisableApiTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If set to <code>true</code>, indicates that the instance cannot be terminated using\n            the Amazon EC2 console, command line tool, or API.</p>",
                         "smithy.api#xmlName": "disableApiTermination"
                     }
@@ -68293,6 +73328,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DisableApiStop",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the instance is enabled for stop protection. \n            For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Stop_Start.html#Using_StopProtection\">Stop Protection</a>.</p>",
                         "smithy.api#xmlName": "disableApiStop"
                     }
@@ -68327,6 +73364,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -68335,6 +73374,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PublicIp",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Elastic IP address.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "publicIp"
@@ -68381,6 +73421,7 @@
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the AMI to restore.</p>",
                         "smithy.api#required": {}
                     }
@@ -68388,6 +73429,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n\t\t\tand provides an error response. If you have the required permissions, the error response is \n\t\t\t<code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -68400,6 +73443,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -68424,12 +73469,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "PrefixListId": {
                     "target": "com.amazonaws.ec2#PrefixListResourceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the prefix list.</p>",
                         "smithy.api#required": {}
                     }
@@ -68437,6 +73485,8 @@
                 "PreviousVersion": {
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The version to restore.</p>",
                         "smithy.api#required": {}
                     }
@@ -68444,6 +73494,8 @@
                 "CurrentVersion": {
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The current version number for the prefix list.</p>",
                         "smithy.api#required": {}
                     }
@@ -68481,6 +73533,7 @@
                 "SnapshotId": {
                     "target": "com.amazonaws.ec2#SnapshotId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the snapshot to restore.</p>",
                         "smithy.api#required": {}
                     }
@@ -68488,6 +73541,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -68524,6 +73579,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the snapshot is encrypted.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -68572,6 +73629,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VolumeSize",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the volume, in GiB.</p>",
                         "smithy.api#xmlName": "volumeSize"
                     }
@@ -68596,6 +73655,7 @@
                 "SnapshotId": {
                     "target": "com.amazonaws.ec2#SnapshotId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the snapshot to restore.</p>",
                         "smithy.api#required": {}
                     }
@@ -68609,22 +73669,23 @@
                 "PermanentRestore": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to permanently restore an archived snapshot. To permanently restore \n      an archived snapshot, specify <code>true</code> and omit the \n      <b>RestoreSnapshotTierRequest$TemporaryRestoreDays</b> parameter.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
             }
         },
         "com.amazonaws.ec2#RestoreSnapshotTierRequestTemporaryRestoreDays": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#RestoreSnapshotTierResult": {
             "type": "structure",
@@ -68649,6 +73710,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RestoreDuration",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>For temporary restores only. The number of days for which the archived snapshot \n      is temporarily restored.</p>",
                         "smithy.api#xmlName": "restoreDuration"
                     }
@@ -68657,6 +73720,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "IsPermanentRestore",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the snapshot is permanently restored. <code>true</code> indicates a permanent \n      restore. <code>false</code> indicates a temporary restore.</p>",
                         "smithy.api#xmlName": "isPermanentRestore"
                     }
@@ -68666,6 +73731,7 @@
         "com.amazonaws.ec2#ResultRange": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 20,
                     "max": 500
@@ -68690,6 +73756,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint with which the authorization rule is associated.</p>",
                         "smithy.api#required": {}
                     }
@@ -68697,6 +73764,7 @@
                 "TargetNetworkCidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IPv4 address range, in CIDR notation, of the network for which access is being removed.</p>",
                         "smithy.api#required": {}
                     }
@@ -68710,12 +73778,16 @@
                 "RevokeAllGroups": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether access should be revoked for all clients.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -68753,6 +73825,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -68761,6 +73835,7 @@
                     "target": "com.amazonaws.ec2#SecurityGroupId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "GroupId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the security group.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "groupId"
@@ -68793,6 +73868,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FromPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>Not supported. Use a set of IP permissions to specify the port.</p>",
                         "smithy.api#xmlName": "fromPort"
                     }
@@ -68809,6 +73886,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ToPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>Not supported. Use a set of IP permissions to specify the port.</p>",
                         "smithy.api#xmlName": "toPort"
                     }
@@ -68838,6 +73917,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -68876,6 +73957,8 @@
                 "FromPort": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The start of port range for the TCP and UDP protocols, or an ICMP type number. For the ICMP type number, \n        use <code>-1</code> to specify all ICMP types.</p>"
                     }
                 },
@@ -68918,6 +74001,8 @@
                 "ToPort": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The end of port range for the TCP and UDP protocols, or an ICMP code number. For the ICMP code number, \n        use <code>-1</code> to specify all ICMP codes for the ICMP type.</p>"
                     }
                 },
@@ -68925,6 +74010,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -68945,6 +74032,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -68960,18 +74049,20 @@
             }
         },
         "com.amazonaws.ec2#RootDeviceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ebs",
-                        "name": "ebs"
-                    },
-                    {
-                        "value": "instance-store",
-                        "name": "instance_store"
+            "type": "enum",
+            "members": {
+                "ebs": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ebs"
                     }
-                ]
+                },
+                "instance_store": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "instance-store"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#RootDeviceTypeList": {
@@ -69132,37 +74223,43 @@
             }
         },
         "com.amazonaws.ec2#RouteOrigin": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "CreateRouteTable",
-                        "name": "CreateRouteTable"
-                    },
-                    {
-                        "value": "CreateRoute",
-                        "name": "CreateRoute"
-                    },
-                    {
-                        "value": "EnableVgwRoutePropagation",
-                        "name": "EnableVgwRoutePropagation"
+            "type": "enum",
+            "members": {
+                "CreateRouteTable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "CreateRouteTable"
                     }
-                ]
+                },
+                "CreateRoute": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "CreateRoute"
+                    }
+                },
+                "EnableVgwRoutePropagation": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "EnableVgwRoutePropagation"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#RouteState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "blackhole",
-                        "name": "blackhole"
+            "type": "enum",
+            "members": {
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
                     }
-                ]
+                },
+                "blackhole": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "blackhole"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#RouteTable": {
@@ -69236,6 +74333,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Main",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether this is the main route table.</p>",
                         "smithy.api#xmlName": "main"
                     }
@@ -69322,30 +74421,38 @@
             }
         },
         "com.amazonaws.ec2#RouteTableAssociationStateCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "associating",
-                        "name": "associating"
-                    },
-                    {
-                        "value": "associated",
-                        "name": "associated"
-                    },
-                    {
-                        "value": "disassociating",
-                        "name": "disassociating"
-                    },
-                    {
-                        "value": "disassociated",
-                        "name": "disassociated"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
+            "type": "enum",
+            "members": {
+                "associating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associating"
                     }
-                ]
+                },
+                "associated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associated"
+                    }
+                },
+                "disassociating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociating"
+                    }
+                },
+                "disassociated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociated"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#RouteTableId": {
@@ -69370,18 +74477,20 @@
             }
         },
         "com.amazonaws.ec2#RuleAction": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "allow",
-                        "name": "allow"
-                    },
-                    {
-                        "value": "deny",
-                        "name": "deny"
+            "type": "enum",
+            "members": {
+                "allow": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "allow"
                     }
-                ]
+                },
+                "deny": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deny"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#RunInstances": {
@@ -69403,6 +74512,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Enabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether detailed monitoring is enabled. Otherwise, basic monitoring is\n            enabled.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "enabled"
@@ -69438,6 +74549,8 @@
                 "Ipv6AddressCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>[EC2-VPC] The number of IPv6 addresses to associate with the primary network\n            interface. Amazon EC2 chooses the IPv6 addresses from the range of your subnet. You\n            cannot specify this option and the option to assign specific IPv6 addresses in the same\n            request. You can specify this option if you've specified a minimum number of instances\n            to launch.</p>\n        <p>You cannot specify this option and the network interfaces option in the same\n            request.</p>"
                     }
                 },
@@ -69463,6 +74576,8 @@
                 "MaxCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of instances to launch. If you specify more instances than Amazon\n            EC2 can launch in the target Availability Zone, Amazon EC2 launches the largest possible\n            number of instances above <code>MinCount</code>.</p>\n        <p>Constraints: Between 1 and the maximum number you're allowed for the specified\n            instance type. For more information about the default limits, and how to request an\n            increase, see <a href=\"http://aws.amazon.com/ec2/faqs/#How_many_instances_can_I_run_in_Amazon_EC2\">How many instances can I\n                run in Amazon EC2</a> in the Amazon EC2 FAQ.</p>",
                         "smithy.api#required": {}
                     }
@@ -69470,6 +74585,8 @@
                 "MinCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum number of instances to launch. If you specify a minimum that is more\n            instances than Amazon EC2 can launch in the target Availability Zone, Amazon EC2\n            launches no instances.</p>\n        <p>Constraints: Between 1 and the maximum number you're allowed for the specified\n            instance type. For more information about the default limits, and how to request an\n            increase, see <a href=\"http://aws.amazon.com/ec2/faqs/#How_many_instances_can_I_run_in_Amazon_EC2\">How many instances can I\n                run in Amazon EC2</a> in the Amazon EC2 General FAQ.</p>",
                         "smithy.api#required": {}
                     }
@@ -69539,6 +74656,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DisableApiTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>If you set this parameter to <code>true</code>, you can't terminate the instance using\n            the Amazon EC2 console, CLI, or API; otherwise, you can. To change this attribute after\n            launch, use <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_ModifyInstanceAttribute.html\">ModifyInstanceAttribute</a>. Alternatively, if you set\n                <code>InstanceInitiatedShutdownBehavior</code> to <code>terminate</code>, you can\n            terminate the instance by running the shutdown command from the instance.</p>\n        <p>Default: <code>false</code>\n        </p>",
                         "smithy.api#xmlName": "disableApiTermination"
                     }
@@ -69547,6 +74666,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -69555,6 +74676,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EbsOptimized",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the instance is optimized for Amazon EBS I/O. This optimization\n            provides dedicated throughput to Amazon EBS and an optimized configuration stack to\n            provide optimal Amazon EBS I/O performance. This optimization isn't available with all\n            instance types. Additional usage charges apply when using an EBS-optimized\n            instance.</p>\n        <p>Default: <code>false</code>\n        </p>",
                         "smithy.api#xmlName": "ebsOptimized"
                     }
@@ -69681,6 +74804,8 @@
                 "DisableApiStop": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether an instance is enabled for stop protection. For more information,\n            see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Stop_Start.html#Using_StopProtection\">Stop\n                protection</a>.\n        </p>"
                     }
                 }
@@ -69717,18 +74842,23 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "InstanceCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of instances.</p>\n         <p>Default: 1</p>"
                     }
                 },
                 "LaunchSpecification": {
                     "target": "com.amazonaws.ec2#ScheduledInstancesLaunchSpecification",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The launch specification. You must match the instance type, Availability Zone, \n         network, and platform of the schedule that you purchased.</p>",
                         "smithy.api#required": {}
                     }
@@ -69736,6 +74866,7 @@
                 "ScheduledInstanceId": {
                     "target": "com.amazonaws.ec2#ScheduledInstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Scheduled Instance ID.</p>",
                         "smithy.api#required": {}
                     }
@@ -69867,6 +74998,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of instances.</p>",
                         "smithy.api#xmlName": "instanceCount"
                     }
@@ -69931,6 +75064,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SlotDurationInHours",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of hours in the schedule.</p>",
                         "smithy.api#xmlName": "slotDurationInHours"
                     }
@@ -69955,6 +75090,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalScheduledInstanceHours",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of hours for a single instance for the entire term.</p>",
                         "smithy.api#xmlName": "totalScheduledInstanceHours"
                     }
@@ -69979,6 +75116,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AvailableInstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of available instances.</p>",
                         "smithy.api#xmlName": "availableInstanceCount"
                     }
@@ -70011,6 +75150,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MaxTermDurationInDays",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum term. The only possible value is 365 days.</p>",
                         "smithy.api#xmlName": "maxTermDurationInDays"
                     }
@@ -70019,6 +75160,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MinTermDurationInDays",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum term. The only possible value is 365 days.</p>",
                         "smithy.api#xmlName": "minTermDurationInDays"
                     }
@@ -70059,6 +75202,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SlotDurationInHours",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of hours in the schedule.</p>",
                         "smithy.api#xmlName": "slotDurationInHours"
                     }
@@ -70067,6 +75212,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalScheduledInstanceHours",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The total number of hours for a single instance for the entire term.</p>",
                         "smithy.api#xmlName": "totalScheduledInstanceHours"
                     }
@@ -70112,6 +75259,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Interval",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The interval quantity. The interval unit depends on the value of <code>frequency</code>. For example, every 2\n         weeks or every 2 months.</p>",
                         "smithy.api#xmlName": "interval"
                     }
@@ -70128,6 +75277,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "OccurrenceRelativeToEnd",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the occurrence is relative to the end of the specified week or month.</p>",
                         "smithy.api#xmlName": "occurrenceRelativeToEnd"
                     }
@@ -70157,6 +75308,8 @@
                 "Interval": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The interval quantity. The interval unit depends on the value of <code>Frequency</code>. For example, every 2 \n         weeks or every 2 months.</p>"
                     }
                 },
@@ -70170,6 +75323,8 @@
                 "OccurrenceRelativeToEnd": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the occurrence is relative to the end of the specified week or month. You can't specify this value with a daily schedule.</p>"
                     }
                 },
@@ -70240,18 +75395,24 @@
                 "DeleteOnTermination": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the volume is deleted on instance termination.</p>"
                     }
                 },
                 "Encrypted": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the volume is encrypted. You can attached encrypted volumes only to instances that support them.</p>"
                     }
                 },
                 "Iops": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of I/O operations per second (IOPS) to provision for an <code>io1</code> or <code>io2</code> volume, with a maximum\n   \t\tratio of 50 IOPS/GiB for <code>io1</code>, and 500 IOPS/GiB for <code>io2</code>. Range is 100 to 64,000 IOPS for\n   \t\tvolumes in most Regions. Maximum IOPS of 64,000 is guaranteed only on\n   \t\t<a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html#ec2-nitro-instances\">instances built on the Nitro System</a>. Other instance families guarantee performance up to\n   \t\t32,000 IOPS. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSVolumeTypes.html\">Amazon EBS volume types</a> in the\n   \t\t<i>Amazon EC2 User Guide</i>.</p>\n   \t     <p>This parameter is valid only for Provisioned IOPS SSD (<code>io1</code> and <code>io2</code>) volumes.</p>"
                     }
                 },
@@ -70264,6 +75425,8 @@
                 "VolumeSize": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the volume, in GiB.</p>\n         <p>Default: If you're creating the volume from a snapshot and don't specify a volume size, the default is the snapshot size.</p>"
                     }
                 },
@@ -70334,6 +75497,8 @@
                 "EbsOptimized": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the instances are optimized for EBS I/O. This optimization provides dedicated throughput to Amazon EBS and an optimized configuration stack to provide optimal EBS I/O performance. This optimization isn't available with all instance types. Additional usage charges apply when using an EBS-optimized instance.</p>\n         <p>Default: <code>false</code>\n         </p>"
                     }
                 },
@@ -70346,6 +75511,7 @@
                 "ImageId": {
                     "target": "com.amazonaws.ec2#ImageId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Amazon Machine Image (AMI).</p>",
                         "smithy.api#required": {}
                     }
@@ -70423,6 +75589,8 @@
                 "Enabled": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether monitoring is enabled.</p>"
                     }
                 }
@@ -70437,12 +75605,16 @@
                 "AssociatePublicIpAddress": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to assign a public IPv4 address to instances launched in a VPC. The\n         public IPv4 address can only be assigned to a network interface for eth0, and can only be\n         assigned to a new network interface, not an existing one. You cannot specify more than one\n         network interface in the request. If launching into a default subnet, the default value is\n         <code>true</code>.</p>"
                     }
                 },
                 "DeleteOnTermination": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether to delete the interface when the instance is terminated.</p>"
                     }
                 },
@@ -70455,6 +75627,8 @@
                 "DeviceIndex": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The index of the device for the network interface attachment.</p>"
                     }
                 },
@@ -70468,6 +75642,8 @@
                 "Ipv6AddressCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of IPv6 addresses to assign to the network interface. The IPv6 addresses are automatically selected from the subnet range.</p>"
                     }
                 },
@@ -70500,6 +75676,8 @@
                 "SecondaryPrivateIpAddressCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of secondary private IPv4 addresses.</p>"
                     }
                 },
@@ -70549,6 +75727,8 @@
                 "Primary": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether this is a primary IPv4 address. Otherwise, this is a secondary IPv4 address.</p>"
                     }
                 },
@@ -70596,6 +75776,7 @@
                 "LocalGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#LocalGatewayRoutetableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the local gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -70622,6 +75803,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -70685,6 +75868,8 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of results to return with a single call.\n\tTo retrieve the remaining results, make another call with the returned <code>nextToken</code> value.</p>"
                     }
                 },
@@ -70697,6 +75882,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -70741,6 +75928,7 @@
                 "TransitGatewayRouteTableId": {
                     "target": "com.amazonaws.ec2#TransitGatewayRouteTableId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the transit gateway route table.</p>",
                         "smithy.api#required": {}
                     }
@@ -70748,6 +75936,7 @@
                 "Filters": {
                     "target": "com.amazonaws.ec2#FilterList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>One or more filters. The possible values are:</p>\n         <ul>\n            <li>\n               <p>\n                  <code>attachment.transit-gateway-attachment-id</code>- The id of the transit gateway attachment.</p>\n            </li>\n            <li>\n               <p>\n                  <code>attachment.resource-id</code> - The resource id of the transit gateway attachment.</p>\n            </li>\n            <li>\n               <p>\n                  <code>attachment.resource-type</code> - The attachment resource type. Valid values\n                    are <code>vpc</code> | <code>vpn</code> | <code>direct-connect-gateway</code> |\n                        <code>peering</code> | <code>connect</code>.</p>\n            </li>\n            <li>\n               <p>\n                  <code>prefix-list-id</code> - The ID of the prefix list.</p>\n            </li>\n            <li>\n               <p>\n                  <code>route-search.exact-match</code> - The exact match of the specified filter.</p>\n            </li>\n            <li>\n               <p>\n                  <code>route-search.longest-prefix-match</code> - The longest prefix that matches the route.</p>\n            </li>\n            <li>\n               <p>\n                  <code>route-search.subnet-of-match</code> - The routes with a subnet that match the specified CIDR filter.</p>\n            </li>\n            <li>\n               <p>\n                  <code>route-search.supernet-of-match</code> - The routes with a CIDR that encompass the CIDR filter. For example, if you have 10.0.1.0/29 and 10.0.1.0/31 routes in your route table and you specify supernet-of-match as 10.0.1.0/30, then the result returns 10.0.1.0/29.</p>\n            </li>\n            <li>\n               <p>\n                  <code>state</code> - The state of the route (<code>active</code> | <code>blackhole</code>).</p>\n            </li>\n            <li>\n               <p>\n                  <code>type</code> - The type of route (<code>propagated</code> |\n                  <code>static</code>).</p>\n            </li>\n         </ul>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "Filter"
@@ -70756,12 +75945,16 @@
                 "MaxResults": {
                     "target": "com.amazonaws.ec2#TransitGatewayMaxResults",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of routes to return.</p>"
                     }
                 },
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -70782,6 +75975,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AdditionalRoutesAvailable",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether there are additional routes available.</p>",
                         "smithy.api#xmlName": "additionalRoutesAvailable"
                     }
@@ -70980,6 +76175,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "IsEgress",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the security group rule is an outbound rule.</p>",
                         "smithy.api#xmlName": "isEgress"
                     }
@@ -70996,6 +76193,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FromPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The start of port range for the TCP and UDP protocols, or an ICMP/ICMPv6 type. A value\n            of -1 indicates all ICMP/ICMPv6 types. If you specify all ICMP/ICMPv6 types, you must\n            specify all codes.</p>",
                         "smithy.api#xmlName": "fromPort"
                     }
@@ -71004,6 +76203,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ToPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The end of port range for the TCP and UDP protocols, or an ICMP/ICMPv6 code. A value of <code>-1</code> indicates all ICMP/ICMPv6 codes. If you specify all ICMP/ICMPv6 types, you must specify all codes. </p>",
                         "smithy.api#xmlName": "toPort"
                     }
@@ -71123,12 +76324,16 @@
                 "FromPort": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The start of port range for the TCP and UDP protocols, or an ICMP/ICMPv6 type. A value of -1 indicates all ICMP/ICMPv6 types. If you specify all ICMP/ICMPv6 types, you must specify all codes.</p>"
                     }
                 },
                 "ToPort": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The end of port range for the TCP and UDP protocols, or an ICMP/ICMPv6 code. A value of <code>-1</code> indicates all ICMP/ICMPv6 codes. If you specify all ICMP/ICMPv6 types, you must specify all codes. </p>"
                     }
                 },
@@ -71206,18 +76411,20 @@
             }
         },
         "com.amazonaws.ec2#SelfServicePortal": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enabled",
-                        "name": "enabled"
-                    },
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
+            "type": "enum",
+            "members": {
+                "enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled"
                     }
-                ]
+                },
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SendDiagnosticInterrupt": {
@@ -71238,6 +76445,7 @@
                 "InstanceId": {
                     "target": "com.amazonaws.ec2#InstanceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the instance.</p>",
                         "smithy.api#required": {}
                     }
@@ -71245,6 +76453,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -71303,6 +76513,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AcceptanceRequired",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether requests from other Amazon Web Services accounts to create an endpoint to the service must first be accepted.</p>",
                         "smithy.api#xmlName": "acceptanceRequired"
                     }
@@ -71311,6 +76523,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ManagesVpcEndpoints",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the service manages its VPC endpoints. Management of the service VPC\n            endpoints using the VPC endpoint API is restricted.</p>",
                         "smithy.api#xmlName": "managesVpcEndpoints"
                     }
@@ -71394,18 +76608,20 @@
             }
         },
         "com.amazonaws.ec2#ServiceConnectivityType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ipv4",
-                        "name": "ipv4"
-                    },
-                    {
-                        "value": "ipv6",
-                        "name": "ipv6"
+            "type": "enum",
+            "members": {
+                "ipv4": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv4"
                     }
-                ]
+                },
+                "ipv6": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv6"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ServiceDetail": {
@@ -71471,7 +76687,7 @@
                     "target": "com.amazonaws.ec2#PrivateDnsDetailsSet",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PrivateDnsNameSet",
-                        "smithy.api#documentation": "<p>The private DNS names assigned to the VPC endpoint service. </p>",
+                        "smithy.api#documentation": "<p>The private DNS names assigned to the VPC endpoint service.</p>",
                         "smithy.api#xmlName": "privateDnsNameSet"
                     }
                 },
@@ -71479,6 +76695,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VpcEndpointPolicySupported",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the service supports endpoint policies.</p>",
                         "smithy.api#xmlName": "vpcEndpointPolicySupported"
                     }
@@ -71487,6 +76705,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AcceptanceRequired",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether VPC endpoint connection requests to the service must be accepted by the service owner.</p>",
                         "smithy.api#xmlName": "acceptanceRequired"
                     }
@@ -71495,6 +76715,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ManagesVpcEndpoints",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the service manages its VPC endpoints. Management of the service VPC\n            endpoints using the VPC endpoint API is restricted.</p>",
                         "smithy.api#xmlName": "managesVpcEndpoints"
                     }
@@ -71546,49 +76768,61 @@
             }
         },
         "com.amazonaws.ec2#ServiceState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Pending",
-                        "name": "Pending"
-                    },
-                    {
-                        "value": "Available",
-                        "name": "Available"
-                    },
-                    {
-                        "value": "Deleting",
-                        "name": "Deleting"
-                    },
-                    {
-                        "value": "Deleted",
-                        "name": "Deleted"
-                    },
-                    {
-                        "value": "Failed",
-                        "name": "Failed"
+            "type": "enum",
+            "members": {
+                "Pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Pending"
                     }
-                ]
+                },
+                "Available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Available"
+                    }
+                },
+                "Deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Deleting"
+                    }
+                },
+                "Deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Deleted"
+                    }
+                },
+                "Failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ServiceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Interface",
-                        "name": "Interface"
-                    },
-                    {
-                        "value": "Gateway",
-                        "name": "Gateway"
-                    },
-                    {
-                        "value": "GatewayLoadBalancer",
-                        "name": "GatewayLoadBalancer"
+            "type": "enum",
+            "members": {
+                "Interface": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Interface"
                     }
-                ]
+                },
+                "Gateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Gateway"
+                    }
+                },
+                "GatewayLoadBalancer": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "GatewayLoadBalancer"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#ServiceTypeDetail": {
@@ -71617,18 +76851,20 @@
             }
         },
         "com.amazonaws.ec2#ShutdownBehavior": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "stop",
-                        "name": "stop"
-                    },
-                    {
-                        "value": "terminate",
-                        "name": "terminate"
+            "type": "enum",
+            "members": {
+                "stop": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "stop"
                     }
-                ]
+                },
+                "terminate": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "terminate"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SlotDateTimeRangeRequest": {
@@ -71637,6 +76873,7 @@
                 "EarliestTime": {
                     "target": "com.amazonaws.ec2#DateTime",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The earliest date and time, in UTC, for the Scheduled Instance to start.</p>",
                         "smithy.api#required": {}
                     }
@@ -71644,6 +76881,7 @@
                 "LatestTime": {
                     "target": "com.amazonaws.ec2#DateTime",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The latest date and time, in UTC, for the Scheduled Instance to start. This value must be later than or equal to the earliest date and at most three months in the future.</p>",
                         "smithy.api#required": {}
                     }
@@ -71696,6 +76934,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the snapshot is encrypted.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -71768,6 +77008,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VolumeSize",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the volume, in GiB.</p>",
                         "smithy.api#xmlName": "volumeSize"
                     }
@@ -71818,18 +77060,20 @@
             }
         },
         "com.amazonaws.ec2#SnapshotAttributeName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "productCodes",
-                        "name": "productCodes"
-                    },
-                    {
-                        "value": "createVolumePermission",
-                        "name": "createVolumePermission"
+            "type": "enum",
+            "members": {
+                "productCodes": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "productCodes"
                     }
-                ]
+                },
+                "createVolumePermission": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "createVolumePermission"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SnapshotDetail": {
@@ -71855,6 +77099,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DiskImageSize",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the disk in the snapshot, in GiB.</p>",
                         "smithy.api#xmlName": "diskImageSize"
                     }
@@ -71996,6 +77242,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the snapshot is encrypted.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -72020,6 +77268,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VolumeSize",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>Size of the volume from which this snapshot was created.</p>",
                         "smithy.api#xmlName": "volumeSize"
                     }
@@ -72145,30 +77395,38 @@
             }
         },
         "com.amazonaws.ec2#SnapshotState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "completed",
-                        "name": "completed"
-                    },
-                    {
-                        "value": "error",
-                        "name": "error"
-                    },
-                    {
-                        "value": "recoverable",
-                        "name": "recoverable"
-                    },
-                    {
-                        "value": "recovering",
-                        "name": "recovering"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "completed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "completed"
+                    }
+                },
+                "error": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "error"
+                    }
+                },
+                "recoverable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "recoverable"
+                    }
+                },
+                "recovering": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "recovering"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SnapshotTaskDetail": {
@@ -72186,6 +77444,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DiskImageSize",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the disk in the snapshot, in GiB.</p>",
                         "smithy.api#xmlName": "diskImageSize"
                     }
@@ -72194,6 +77454,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the snapshot is encrypted.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -72330,6 +77592,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "LastTieringProgress",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The progress of the last archive or restore process, as a percentage.</p>",
                         "smithy.api#xmlName": "lastTieringProgress"
                     }
@@ -72372,26 +77636,32 @@
             }
         },
         "com.amazonaws.ec2#SpotAllocationStrategy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "lowest-price",
-                        "name": "LOWEST_PRICE"
-                    },
-                    {
-                        "value": "diversified",
-                        "name": "DIVERSIFIED"
-                    },
-                    {
-                        "value": "capacity-optimized",
-                        "name": "CAPACITY_OPTIMIZED"
-                    },
-                    {
-                        "value": "capacity-optimized-prioritized",
-                        "name": "CAPACITY_OPTIMIZED_PRIORITIZED"
+            "type": "enum",
+            "members": {
+                "LOWEST_PRICE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "lowest-price"
                     }
-                ]
+                },
+                "DIVERSIFIED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "diversified"
+                    }
+                },
+                "CAPACITY_OPTIMIZED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "capacity-optimized"
+                    }
+                },
+                "CAPACITY_OPTIMIZED_PRIORITIZED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "capacity-optimized-prioritized"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SpotCapacityRebalance": {
@@ -72409,6 +77679,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TerminationDelay",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The amount of time (in seconds) that Amazon EC2 waits before terminating the old Spot\n            Instance after launching a new replacement Spot Instance.</p>\n        <p>Required when <code>ReplacementStrategy</code> is set to <code>launch-before-terminate</code>.</p>\n        <p>Not valid when <code>ReplacementStrategy</code> is set to <code>launch</code>.</p>\n        <p>Valid values: Minimum value of <code>120</code> seconds. Maximum value of <code>7200</code> seconds.</p>",
                         "smithy.api#xmlName": "terminationDelay"
                     }
@@ -72497,6 +77769,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EbsOptimized",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the instances are optimized for EBS I/O. This optimization provides dedicated throughput to Amazon EBS and an optimized configuration stack to provide optimal EBS I/O performance. This optimization isn't available with all instance types. Additional usage charges apply when using an EBS Optimized instance.</p>\n         <p>Default: <code>false</code>\n         </p>",
                         "smithy.api#xmlName": "ebsOptimized"
                     }
@@ -72601,6 +77875,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "WeightedCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of units provided by the specified instance type. These are the same units that you chose to set the target capacity in terms of instances, or a performance characteristic such as vCPUs, memory, or I/O.</p> \n         <p>If the target capacity divided by this value is not a whole number, Amazon EC2 rounds the number of instances to the next whole number. If this value is not specified, the default is 1.</p>",
                         "smithy.api#xmlName": "weightedCapacity"
                     }
@@ -72633,6 +77909,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Enabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Enables monitoring for the instance.</p>\n         <p>Default: <code>false</code>\n         </p>",
                         "smithy.api#xmlName": "enabled"
                     }
@@ -72745,6 +78023,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FulfilledCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of units fulfilled by this request compared to the set target capacity. You\n            cannot set this value.</p>",
                         "smithy.api#xmlName": "fulfilledCapacity"
                     }
@@ -72753,6 +78033,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "OnDemandFulfilledCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of On-Demand units fulfilled by this request compared to the set target\n            On-Demand capacity.</p>",
                         "smithy.api#xmlName": "onDemandFulfilledCapacity"
                     }
@@ -72761,6 +78043,7 @@
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
                         "aws.protocols#ec2QueryName": "IamFleetRole",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Amazon Resource Name (ARN) of an Identity and Access Management (IAM) role that\n            grants the Spot Fleet the permission to request, launch, terminate, and tag instances on\n            your behalf. For more information, see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/spot-fleet-requests.html#spot-fleet-prerequisites\">Spot\n                Fleet prerequisites</a> in the <i>Amazon EC2 User Guide for Linux Instances</i>. Spot Fleet\n            can terminate Spot Instances on your behalf when you cancel its Spot Fleet request using\n                <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CancelSpotFleetRequests\">CancelSpotFleetRequests</a> or when the Spot Fleet request expires, if you set\n                <code>TerminateInstancesWithExpiration</code>.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "iamFleetRole"
@@ -72794,6 +78077,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TargetCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of units to request for the Spot Fleet. You can choose to set the target\n            capacity in terms of instances or a performance characteristic that is important to your\n            application workload, such as vCPUs, memory, or I/O. If the request type is\n                <code>maintain</code>, you can specify a target capacity of 0 and add capacity\n            later.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "targetCapacity"
@@ -72803,6 +78088,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "OnDemandTargetCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of On-Demand units to request. You can choose to set the target capacity in\n            terms of instances or a performance characteristic that is important to your application\n            workload, such as vCPUs, memory, or I/O. If the request type is <code>maintain</code>,\n            you can specify a target capacity of 0 and add capacity later.</p>",
                         "smithy.api#xmlName": "onDemandTargetCapacity"
                     }
@@ -72827,6 +78114,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TerminateInstancesWithExpiration",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether running Spot Instances are terminated when the Spot Fleet request\n            expires.</p>",
                         "smithy.api#xmlName": "terminateInstancesWithExpiration"
                     }
@@ -72859,6 +78148,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ReplaceUnhealthyInstances",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether Spot Fleet should replace unhealthy instances.</p>",
                         "smithy.api#xmlName": "replaceUnhealthyInstances"
                     }
@@ -72883,6 +78174,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstancePoolsToUseCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of Spot pools across which to allocate your target Spot capacity. Valid\n            only when Spot <b>AllocationStrategy</b> is set to\n                <code>lowest-price</code>. Spot Fleet selects the cheapest Spot pools and evenly\n            allocates your target Spot capacity across the number of Spot pools that you\n            specify.</p>\n        <p>Note that Spot Fleet attempts to draw Spot Instances from the number of pools that you specify on a\n            best effort basis. If a pool runs out of Spot capacity before fulfilling your target\n            capacity, Spot Fleet will continue to fulfill your request by drawing from the next cheapest\n            pool. To ensure that your target capacity is met, you might receive Spot Instances from more than\n            the number of pools that you specified. Similarly, if most of the pools have no Spot\n            capacity, you might receive your full target capacity from fewer than the number of\n            pools that you specified.</p>",
                         "smithy.api#xmlName": "instancePoolsToUseCount"
                     }
@@ -72970,22 +78263,26 @@
             }
         },
         "com.amazonaws.ec2#SpotInstanceInterruptionBehavior": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "hibernate",
-                        "name": "hibernate"
-                    },
-                    {
-                        "value": "stop",
-                        "name": "stop"
-                    },
-                    {
-                        "value": "terminate",
-                        "name": "terminate"
+            "type": "enum",
+            "members": {
+                "hibernate": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "hibernate"
                     }
-                ]
+                },
+                "stop": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "stop"
+                    }
+                },
+                "terminate": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "terminate"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SpotInstanceRequest": {
@@ -73011,6 +78308,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "BlockDurationMinutes",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>Deprecated.</p>",
                         "smithy.api#xmlName": "blockDurationMinutes"
                     }
@@ -73170,30 +78469,38 @@
             }
         },
         "com.amazonaws.ec2#SpotInstanceState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "open",
-                        "name": "open"
-                    },
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "closed",
-                        "name": "closed"
-                    },
-                    {
-                        "value": "cancelled",
-                        "name": "cancelled"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
+            "type": "enum",
+            "members": {
+                "open": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "open"
                     }
-                ]
+                },
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "closed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "closed"
+                    }
+                },
+                "cancelled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "cancelled"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SpotInstanceStateFault": {
@@ -73253,18 +78560,20 @@
             }
         },
         "com.amazonaws.ec2#SpotInstanceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "one-time",
-                        "name": "one_time"
-                    },
-                    {
-                        "value": "persistent",
-                        "name": "persistent"
+            "type": "enum",
+            "members": {
+                "one_time": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "one-time"
                     }
-                ]
+                },
+                "persistent": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "persistent"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SpotMaintenanceStrategies": {
@@ -73301,6 +78610,8 @@
                 "BlockDurationMinutes": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>Deprecated.</p>"
                     }
                 },
@@ -73352,6 +78663,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstancePoolsToUseCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of Spot pools across which to allocate your target Spot capacity. Supported\n         only when <code>AllocationStrategy</code> is set to <code>lowest-price</code>. EC2 Fleet selects\n         the cheapest Spot pools and evenly allocates your target Spot capacity across the number of\n         Spot pools that you specify.</p>\n         <p>Note that EC2 Fleet attempts to draw Spot Instances from the number of pools that you specify on a\n         best effort basis. If a pool runs out of Spot capacity before fulfilling your target\n         capacity, EC2 Fleet will continue to fulfill your request by drawing from the next cheapest\n         pool. To ensure that your target capacity is met, you might receive Spot Instances from more than\n         the number of pools that you specified. Similarly, if most of the pools have no Spot\n         capacity, you might receive your full target capacity from fewer than the number of pools\n         that you specified.</p>",
                         "smithy.api#xmlName": "instancePoolsToUseCount"
                     }
@@ -73360,6 +78673,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SingleInstanceType",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates that the fleet uses a single instance type to launch all Spot Instances in the\n         fleet.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>",
                         "smithy.api#xmlName": "singleInstanceType"
                     }
@@ -73368,6 +78683,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SingleAvailabilityZone",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates that the fleet launches all Spot Instances into a single Availability Zone.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>",
                         "smithy.api#xmlName": "singleAvailabilityZone"
                     }
@@ -73376,6 +78693,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MinTargetCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum target capacity for Spot Instances in the fleet. If the minimum target capacity is\n         not reached, the fleet launches no instances.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>\n         <p>At least one of the following must be specified: <code>SingleAvailabilityZone</code> |\n            <code>SingleInstanceType</code>\n         </p>",
                         "smithy.api#xmlName": "minTargetCapacity"
                     }
@@ -73417,24 +78736,32 @@
                 "InstancePoolsToUseCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of Spot pools across which to allocate your target Spot capacity. Supported\n         only when Spot <code>AllocationStrategy</code> is set to <code>lowest-price</code>. EC2 Fleet\n         selects the cheapest Spot pools and evenly allocates your target Spot capacity across the\n         number of Spot pools that you specify.</p>\n         <p>Note that EC2 Fleet attempts to draw Spot Instances from the number of pools that you specify on a\n         best effort basis. If a pool runs out of Spot capacity before fulfilling your target\n         capacity, EC2 Fleet will continue to fulfill your request by drawing from the next cheapest\n         pool. To ensure that your target capacity is met, you might receive Spot Instances from more than\n         the number of pools that you specified. Similarly, if most of the pools have no Spot\n         capacity, you might receive your full target capacity from fewer than the number of pools\n         that you specified.</p>"
                     }
                 },
                 "SingleInstanceType": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates that the fleet uses a single instance type to launch all Spot Instances in the\n         fleet.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>"
                     }
                 },
                 "SingleAvailabilityZone": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates that the fleet launches all Spot Instances into a single Availability Zone.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>"
                     }
                 },
                 "MinTargetCapacity": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum target capacity for Spot Instances in the fleet. If the minimum target capacity is\n         not reached, the fleet launches no instances.</p>\n         <p>Supported only for fleets of type <code>instant</code>.</p>\n         <p>At least one of the following must be specified: <code>SingleAvailabilityZone</code> |\n         <code>SingleInstanceType</code>\n         </p>"
                     }
                 },
@@ -73504,6 +78831,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Score",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The placement score, on a scale from <code>1</code> to <code>10</code>. A score of\n            <code>10</code> indicates that your Spot request is highly likely to succeed in this\n         Region or Availability Zone. A score of <code>1</code> indicates that your Spot request is\n         not likely to succeed. </p>",
                         "smithy.api#xmlName": "score"
                     }
@@ -73525,6 +78854,7 @@
         "com.amazonaws.ec2#SpotPlacementScoresMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 10,
                     "max": 1000
@@ -73534,6 +78864,7 @@
         "com.amazonaws.ec2#SpotPlacementScoresTargetCapacity": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 1,
                     "max": 2000000000
@@ -73598,18 +78929,20 @@
             }
         },
         "com.amazonaws.ec2#SpreadLevel": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "host",
-                        "name": "host"
-                    },
-                    {
-                        "value": "rack",
-                        "name": "rack"
+            "type": "enum",
+            "members": {
+                "host": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "host"
                     }
-                ]
+                },
+                "rack": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "rack"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#StaleIpPermission": {
@@ -73619,6 +78952,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FromPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The start of the port range for the TCP and UDP protocols, or an ICMP type number. A value of\n        <code>-1</code> indicates all ICMP types. </p>",
                         "smithy.api#xmlName": "fromPort"
                     }
@@ -73651,6 +78986,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ToPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The end of the port range for the TCP and UDP protocols, or an ICMP type number. A value of\n        <code>-1</code> indicates all ICMP types. </p>",
                         "smithy.api#xmlName": "toPort"
                     }
@@ -73760,6 +79097,7 @@
                 "InstanceIds": {
                     "target": "com.amazonaws.ec2#InstanceIdStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the instances.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "InstanceId"
@@ -73777,6 +79115,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -73814,6 +79154,7 @@
                 "NetworkInsightsAccessScopeId": {
                     "target": "com.amazonaws.ec2#NetworkInsightsAccessScopeId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Network Access Scope.</p>",
                         "smithy.api#required": {}
                     }
@@ -73821,6 +79162,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -73834,6 +79177,7 @@
                 "ClientToken": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Unique, case-sensitive identifier that you provide to ensure the idempotency of the request. For more information, \n   see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/Run_Instance_Idempotency.html\">How to ensure idempotency</a>.</p>",
                         "smithy.api#idempotencyToken": {},
                         "smithy.api#required": {}
@@ -73872,6 +79216,7 @@
                 "NetworkInsightsPathId": {
                     "target": "com.amazonaws.ec2#NetworkInsightsPathId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the path.</p>",
                         "smithy.api#required": {}
                     }
@@ -73886,6 +79231,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -73899,6 +79246,7 @@
                 "ClientToken": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>Unique, case-sensitive identifier that you provide to ensure the idempotency of the request. For more information, \n   see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/APIReference/Run_Instance_Idempotency.html\">How to ensure idempotency</a>.</p>",
                         "smithy.api#idempotencyToken": {},
                         "smithy.api#required": {}
@@ -73937,12 +79285,15 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
                 "ServiceId": {
                     "target": "com.amazonaws.ec2#VpcEndpointServiceId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the endpoint service.</p>",
                         "smithy.api#required": {}
                     }
@@ -73956,6 +79307,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, it returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -73963,42 +79316,56 @@
             }
         },
         "com.amazonaws.ec2#State": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "PendingAcceptance",
-                        "name": "PendingAcceptance"
-                    },
-                    {
-                        "value": "Pending",
-                        "name": "Pending"
-                    },
-                    {
-                        "value": "Available",
-                        "name": "Available"
-                    },
-                    {
-                        "value": "Deleting",
-                        "name": "Deleting"
-                    },
-                    {
-                        "value": "Deleted",
-                        "name": "Deleted"
-                    },
-                    {
-                        "value": "Rejected",
-                        "name": "Rejected"
-                    },
-                    {
-                        "value": "Failed",
-                        "name": "Failed"
-                    },
-                    {
-                        "value": "Expired",
-                        "name": "Expired"
+            "type": "enum",
+            "members": {
+                "PendingAcceptance": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "PendingAcceptance"
                     }
-                ]
+                },
+                "Pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Pending"
+                    }
+                },
+                "Available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Available"
+                    }
+                },
+                "Deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Deleting"
+                    }
+                },
+                "Deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Deleted"
+                    }
+                },
+                "Rejected": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Rejected"
+                    }
+                },
+                "Failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Failed"
+                    }
+                },
+                "Expired": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Expired"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#StateReason": {
@@ -74026,71 +79393,83 @@
             }
         },
         "com.amazonaws.ec2#StaticSourcesSupportValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#Status": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "MoveInProgress",
-                        "name": "moveInProgress"
-                    },
-                    {
-                        "value": "InVpc",
-                        "name": "inVpc"
-                    },
-                    {
-                        "value": "InClassic",
-                        "name": "inClassic"
+            "type": "enum",
+            "members": {
+                "moveInProgress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "MoveInProgress"
                     }
-                ]
+                },
+                "inVpc": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "InVpc"
+                    }
+                },
+                "inClassic": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "InClassic"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#StatusName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "reachability",
-                        "name": "reachability"
+            "type": "enum",
+            "members": {
+                "reachability": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "reachability"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#StatusType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "passed",
-                        "name": "passed"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
-                    },
-                    {
-                        "value": "insufficient-data",
-                        "name": "insufficient_data"
-                    },
-                    {
-                        "value": "initializing",
-                        "name": "initializing"
+            "type": "enum",
+            "members": {
+                "passed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "passed"
                     }
-                ]
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "insufficient_data": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "insufficient-data"
+                    }
+                },
+                "initializing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "initializing"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#StopInstances": {
@@ -74111,6 +79490,7 @@
                 "InstanceIds": {
                     "target": "com.amazonaws.ec2#InstanceIdStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the instances.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "InstanceId"
@@ -74119,6 +79499,8 @@
                 "Hibernate": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Hibernates the instance if the instance was enabled for hibernation at launch. If the\n            instance cannot hibernate successfully, a normal shutdown occurs. For more information,\n            see <a href=\"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Hibernate.html\">Hibernate\n                your instance</a> in the <i>Amazon EC2 User Guide</i>.</p>\n        <p> Default: <code>false</code>\n         </p>"
                     }
                 },
@@ -74126,6 +79508,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -74134,6 +79518,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Force",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Forces the instances to stop. The instances do not have an opportunity to flush file\n            system caches or file system metadata. If you use this option, you must perform file\n            system check and repair procedures. This option is not recommended for Windows\n            instances.</p>\n        <p>Default: <code>false</code>\n        </p>",
                         "smithy.api#xmlName": "force"
                     }
@@ -74189,18 +79575,20 @@
             }
         },
         "com.amazonaws.ec2#StorageTier": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "archive",
-                        "name": "archive"
-                    },
-                    {
-                        "value": "standard",
-                        "name": "standard"
+            "type": "enum",
+            "members": {
+                "archive": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "archive"
                     }
-                ]
+                },
+                "standard": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "standard"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#StoreImageTaskResult": {
@@ -74242,6 +79630,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ProgressPercentage",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The progress of the task as a percentage.</p>",
                         "smithy.api#xmlName": "progressPercentage"
                     }
@@ -74320,6 +79710,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AvailableIpAddressCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of unused private IPv4 addresses in the subnet. The IPv4 addresses for any\n\t\t\tstopped instances are considered unavailable.</p>",
                         "smithy.api#xmlName": "availableIpAddressCount"
                     }
@@ -74336,6 +79728,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DefaultForAz",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether this is the default subnet for the Availability Zone.</p>",
                         "smithy.api#xmlName": "defaultForAz"
                     }
@@ -74344,6 +79738,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnableLniAtDeviceIndex",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>\n            Indicates the device position for local network interfaces in this subnet. For example, \n            <code>1</code> indicates local network interfaces in this subnet are the secondary \n            network interface (eth1). \n        </p>",
                         "smithy.api#xmlName": "enableLniAtDeviceIndex"
                     }
@@ -74352,6 +79748,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MapPublicIpOnLaunch",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether instances launched in this subnet receive a public IPv4 address.</p>",
                         "smithy.api#xmlName": "mapPublicIpOnLaunch"
                     }
@@ -74360,6 +79758,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MapCustomerOwnedIpOnLaunch",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether a network interface created in this subnet (including a network\n            interface created by <a>RunInstances</a>) receives a customer-owned IPv4 address.</p>",
                         "smithy.api#xmlName": "mapCustomerOwnedIpOnLaunch"
                     }
@@ -74408,6 +79808,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AssignIpv6AddressOnCreation",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether a network interface created in this subnet (including a network\n            interface created by <a>RunInstances</a>) receives an IPv6 address.</p>",
                         "smithy.api#xmlName": "assignIpv6AddressOnCreation"
                     }
@@ -74448,6 +79850,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnableDns64",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether DNS queries made to the Amazon-provided DNS Resolver in this subnet \n            should return synthetic IPv6 addresses for IPv4-only destinations.</p>",
                         "smithy.api#xmlName": "enableDns64"
                     }
@@ -74456,6 +79860,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Ipv6Native",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether this is an IPv6 only subnet.</p>",
                         "smithy.api#xmlName": "ipv6Native"
                     }
@@ -74534,34 +79940,44 @@
             }
         },
         "com.amazonaws.ec2#SubnetCidrBlockStateCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "associating",
-                        "name": "associating"
-                    },
-                    {
-                        "value": "associated",
-                        "name": "associated"
-                    },
-                    {
-                        "value": "disassociating",
-                        "name": "disassociating"
-                    },
-                    {
-                        "value": "disassociated",
-                        "name": "disassociated"
-                    },
-                    {
-                        "value": "failing",
-                        "name": "failing"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
+            "type": "enum",
+            "members": {
+                "associating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associating"
                     }
-                ]
+                },
+                "associated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associated"
+                    }
+                },
+                "disassociating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociating"
+                    }
+                },
+                "disassociated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociated"
+                    }
+                },
+                "failing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failing"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SubnetCidrReservation": {
@@ -74641,18 +80057,20 @@
             }
         },
         "com.amazonaws.ec2#SubnetCidrReservationType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "prefix",
-                        "name": "prefix"
-                    },
-                    {
-                        "value": "explicit",
-                        "name": "explicit"
+            "type": "enum",
+            "members": {
+                "prefix": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "prefix"
                     }
-                ]
+                },
+                "explicit": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "explicit"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SubnetId": {
@@ -74718,18 +80136,20 @@
             }
         },
         "com.amazonaws.ec2#SubnetState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SuccessfulInstanceCreditSpecificationItem": {
@@ -74783,30 +80203,38 @@
             }
         },
         "com.amazonaws.ec2#SummaryStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ok",
-                        "name": "ok"
-                    },
-                    {
-                        "value": "impaired",
-                        "name": "impaired"
-                    },
-                    {
-                        "value": "insufficient-data",
-                        "name": "insufficient_data"
-                    },
-                    {
-                        "value": "not-applicable",
-                        "name": "not_applicable"
-                    },
-                    {
-                        "value": "initializing",
-                        "name": "initializing"
+            "type": "enum",
+            "members": {
+                "ok": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ok"
                     }
-                ]
+                },
+                "impaired": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "impaired"
+                    }
+                },
+                "insufficient_data": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "insufficient-data"
+                    }
+                },
+                "not_applicable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "not-applicable"
+                    }
+                },
+                "initializing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "initializing"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#SupportedIpAddressTypes": {
@@ -74948,6 +80376,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TotalTargetCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of units to request, filled using\n         <code>DefaultTargetCapacityType</code>.</p>",
                         "smithy.api#xmlName": "totalTargetCapacity"
                     }
@@ -74956,6 +80386,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "OnDemandTargetCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of On-Demand units to request. If you specify a target capacity for Spot units, you cannot specify a target capacity for On-Demand units.</p>",
                         "smithy.api#xmlName": "onDemandTargetCapacity"
                     }
@@ -74964,6 +80396,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SpotTargetCapacity",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of Spot units to launch. If you specify a target capacity for On-Demand units, you cannot specify a target capacity for Spot units.</p>",
                         "smithy.api#xmlName": "spotTargetCapacity"
                     }
@@ -74995,6 +80429,8 @@
                 "TotalTargetCapacity": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of units to request, filled using\n         <code>DefaultTargetCapacityType</code>.</p>",
                         "smithy.api#required": {}
                     }
@@ -75002,12 +80438,16 @@
                 "OnDemandTargetCapacity": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of On-Demand units to request.</p>"
                     }
                 },
                 "SpotTargetCapacity": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of Spot units to request.</p>"
                     }
                 },
@@ -75029,22 +80469,26 @@
             }
         },
         "com.amazonaws.ec2#TargetCapacityUnitType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "vcpu",
-                        "name": "VCPU"
-                    },
-                    {
-                        "value": "memory-mib",
-                        "name": "MEMORY_MIB"
-                    },
-                    {
-                        "value": "units",
-                        "name": "UNITS"
+            "type": "enum",
+            "members": {
+                "VCPU": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vcpu"
                     }
-                ]
+                },
+                "MEMORY_MIB": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "memory-mib"
+                    }
+                },
+                "UNITS": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "units"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TargetConfiguration": {
@@ -75054,6 +80498,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "InstanceCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of instances the Convertible Reserved Instance offering can be applied to. This parameter is \n      reserved and cannot be specified in a request</p>",
                         "smithy.api#xmlName": "instanceCount"
                     }
@@ -75077,12 +80523,15 @@
                 "InstanceCount": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of instances the Convertible Reserved Instance offering can be applied to. This parameter is reserved and cannot \n      be specified in a request</p>"
                     }
                 },
                 "OfferingId": {
                     "target": "com.amazonaws.ec2#ReservedInstancesOfferingId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The Convertible Reserved Instance offering ID.</p>",
                         "smithy.api#required": {}
                     }
@@ -75247,48 +80696,54 @@
             }
         },
         "com.amazonaws.ec2#TargetStorageTier": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "archive",
-                        "name": "archive"
+            "type": "enum",
+            "members": {
+                "archive": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "archive"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#TelemetryStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "UP",
-                        "name": "UP"
-                    },
-                    {
-                        "value": "DOWN",
-                        "name": "DOWN"
+            "type": "enum",
+            "members": {
+                "UP": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "UP"
                     }
-                ]
+                },
+                "DOWN": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "DOWN"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#Tenancy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "default",
-                        "name": "default"
-                    },
-                    {
-                        "value": "dedicated",
-                        "name": "dedicated"
-                    },
-                    {
-                        "value": "host",
-                        "name": "host"
+            "type": "enum",
+            "members": {
+                "default": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "default"
                     }
-                ]
+                },
+                "dedicated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "dedicated"
+                    }
+                },
+                "host": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "host"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TerminateClientVpnConnections": {
@@ -75309,6 +80764,7 @@
                 "ClientVpnEndpointId": {
                     "target": "com.amazonaws.ec2#ClientVpnEndpointId",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the Client VPN endpoint to which the client is connected.</p>",
                         "smithy.api#required": {}
                     }
@@ -75328,6 +80784,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -75421,6 +80879,7 @@
                 "InstanceIds": {
                     "target": "com.amazonaws.ec2#InstanceIdStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the instances.</p>\n        <p>Constraints: Up to 1000 instance IDs. We recommend breaking up this request into\n            smaller batches.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "InstanceId"
@@ -75430,6 +80889,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -75450,10 +80911,7 @@
             }
         },
         "com.amazonaws.ec2#ThreadsPerCore": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#ThreadsPerCoreList": {
             "type": "list",
@@ -75513,46 +80971,62 @@
             }
         },
         "com.amazonaws.ec2#TieringOperationStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "archival-in-progress",
-                        "name": "archival_in_progress"
-                    },
-                    {
-                        "value": "archival-completed",
-                        "name": "archival_completed"
-                    },
-                    {
-                        "value": "archival-failed",
-                        "name": "archival_failed"
-                    },
-                    {
-                        "value": "temporary-restore-in-progress",
-                        "name": "temporary_restore_in_progress"
-                    },
-                    {
-                        "value": "temporary-restore-completed",
-                        "name": "temporary_restore_completed"
-                    },
-                    {
-                        "value": "temporary-restore-failed",
-                        "name": "temporary_restore_failed"
-                    },
-                    {
-                        "value": "permanent-restore-in-progress",
-                        "name": "permanent_restore_in_progress"
-                    },
-                    {
-                        "value": "permanent-restore-completed",
-                        "name": "permanent_restore_completed"
-                    },
-                    {
-                        "value": "permanent-restore-failed",
-                        "name": "permanent_restore_failed"
+            "type": "enum",
+            "members": {
+                "archival_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "archival-in-progress"
                     }
-                ]
+                },
+                "archival_completed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "archival-completed"
+                    }
+                },
+                "archival_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "archival-failed"
+                    }
+                },
+                "temporary_restore_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "temporary-restore-in-progress"
+                    }
+                },
+                "temporary_restore_completed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "temporary-restore-completed"
+                    }
+                },
+                "temporary_restore_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "temporary-restore-failed"
+                    }
+                },
+                "permanent_restore_in_progress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "permanent-restore-in-progress"
+                    }
+                },
+                "permanent_restore_completed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "permanent-restore-completed"
+                    }
+                },
+                "permanent_restore_failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "permanent-restore-failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TotalLocalStorageGB": {
@@ -75562,6 +81036,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Min",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum amount of total local storage, in GB. If this parameter is not specified, there is\n         no minimum limit.</p>",
                         "smithy.api#xmlName": "min"
                     }
@@ -75570,6 +81046,8 @@
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Max",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum amount of total local storage, in GB. If this parameter is not specified, there is\n         no maximum limit.</p>",
                         "smithy.api#xmlName": "max"
                     }
@@ -75585,12 +81063,16 @@
                 "Min": {
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum amount of total local storage, in GB. To specify no minimum limit, omit this\n         parameter.</p>"
                     }
                 },
                 "Max": {
                     "target": "com.amazonaws.ec2#Double",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum amount of total local storage, in GB. To specify no maximum limit, omit this\n         parameter.</p>"
                     }
                 }
@@ -75600,29 +81082,31 @@
             }
         },
         "com.amazonaws.ec2#TpmSupportValues": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "v2.0",
-                        "name": "v2_0"
+            "type": "enum",
+            "members": {
+                "v2_0": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "v2.0"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#TrafficDirection": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ingress",
-                        "name": "ingress"
-                    },
-                    {
-                        "value": "egress",
-                        "name": "egress"
+            "type": "enum",
+            "members": {
+                "ingress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ingress"
                     }
-                ]
+                },
+                "egress": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "egress"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TrafficMirrorFilter": {
@@ -75724,6 +81208,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RuleNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The rule number of the Traffic Mirror rule.</p>",
                         "smithy.api#xmlName": "ruleNumber"
                     }
@@ -75740,6 +81226,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Protocol",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The protocol assigned to the Traffic Mirror rule.</p>",
                         "smithy.api#xmlName": "protocol"
                     }
@@ -75790,26 +81278,32 @@
             }
         },
         "com.amazonaws.ec2#TrafficMirrorFilterRuleField": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "destination-port-range",
-                        "name": "destination_port_range"
-                    },
-                    {
-                        "value": "source-port-range",
-                        "name": "source_port_range"
-                    },
-                    {
-                        "value": "protocol",
-                        "name": "protocol"
-                    },
-                    {
-                        "value": "description",
-                        "name": "description"
+            "type": "enum",
+            "members": {
+                "destination_port_range": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "destination-port-range"
                     }
-                ]
+                },
+                "source_port_range": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "source-port-range"
+                    }
+                },
+                "protocol": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "protocol"
+                    }
+                },
+                "description": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "description"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TrafficMirrorFilterRuleFieldList": {
@@ -75840,14 +81334,14 @@
             }
         },
         "com.amazonaws.ec2#TrafficMirrorNetworkService": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "amazon-dns",
-                        "name": "amazon_dns"
+            "type": "enum",
+            "members": {
+                "amazon_dns": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "amazon-dns"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#TrafficMirrorNetworkServiceList": {
@@ -75866,6 +81360,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FromPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The start of the Traffic Mirror port range. This applies to the TCP and UDP protocols.</p>",
                         "smithy.api#xmlName": "fromPort"
                     }
@@ -75874,6 +81370,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ToPort",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The end of the Traffic Mirror port range. This applies to the TCP and UDP protocols.</p>",
                         "smithy.api#xmlName": "toPort"
                     }
@@ -75889,12 +81387,16 @@
                 "FromPort": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The first port in the Traffic Mirror port range. This applies to the TCP and UDP protocols.</p>"
                     }
                 },
                 "ToPort": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The last port in the Traffic Mirror port range. This applies to the TCP and UDP protocols.</p>"
                     }
                 }
@@ -75904,18 +81406,20 @@
             }
         },
         "com.amazonaws.ec2#TrafficMirrorRuleAction": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "accept",
-                        "name": "accept"
-                    },
-                    {
-                        "value": "reject",
-                        "name": "reject"
+            "type": "enum",
+            "members": {
+                "accept": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "accept"
                     }
-                ]
+                },
+                "reject": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "reject"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TrafficMirrorSession": {
@@ -75965,6 +81469,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PacketLength",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of bytes in each packet to mirror. These are the bytes after the VXLAN header. To mirror a subset, set this to the length (in bytes) to mirror. For example, if you set this value to 100, then the first 100 bytes that meet the filter criteria are copied to the target. Do not specify this parameter when you want to mirror the entire packet</p>",
                         "smithy.api#xmlName": "packetLength"
                     }
@@ -75973,6 +81479,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "SessionNumber",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The session number determines the order in which sessions are evaluated when an interface is used by multiple sessions. The first session with a matching filter is the one that mirrors the packets.</p>\n         <p>Valid values are 1-32766.</p>",
                         "smithy.api#xmlName": "sessionNumber"
                     }
@@ -75981,6 +81489,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VirtualNetworkId",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The virtual network ID associated with the Traffic Mirror session.</p>",
                         "smithy.api#xmlName": "virtualNetworkId"
                     }
@@ -76007,22 +81517,26 @@
             }
         },
         "com.amazonaws.ec2#TrafficMirrorSessionField": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "packet-length",
-                        "name": "packet_length"
-                    },
-                    {
-                        "value": "description",
-                        "name": "description"
-                    },
-                    {
-                        "value": "virtual-network-id",
-                        "name": "virtual_network_id"
+            "type": "enum",
+            "members": {
+                "packet_length": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "packet-length"
                     }
-                ]
+                },
+                "description": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "description"
+                    }
+                },
+                "virtual_network_id": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "virtual-network-id"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TrafficMirrorSessionFieldList": {
@@ -76146,27 +81660,32 @@
             }
         },
         "com.amazonaws.ec2#TrafficMirrorTargetType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "network-interface",
-                        "name": "network_interface"
-                    },
-                    {
-                        "value": "network-load-balancer",
-                        "name": "network_load_balancer"
-                    },
-                    {
-                        "value": "gateway-load-balancer-endpoint",
-                        "name": "gateway_load_balancer_endpoint"
+            "type": "enum",
+            "members": {
+                "network_interface": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "network-interface"
                     }
-                ]
+                },
+                "network_load_balancer": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "network-load-balancer"
+                    }
+                },
+                "gateway_load_balancer_endpoint": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "gateway-load-balancer-endpoint"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TrafficMirroringMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -76174,22 +81693,26 @@
             }
         },
         "com.amazonaws.ec2#TrafficType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ACCEPT",
-                        "name": "ACCEPT"
-                    },
-                    {
-                        "value": "REJECT",
-                        "name": "REJECT"
-                    },
-                    {
-                        "value": "ALL",
-                        "name": "ALL"
+            "type": "enum",
+            "members": {
+                "ACCEPT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ACCEPT"
                     }
-                ]
+                },
+                "REJECT": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "REJECT"
+                    }
+                },
+                "ALL": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ALL"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitAssociationGatewayId": {
@@ -76316,26 +81839,32 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayAssociationState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "associating",
-                        "name": "associating"
-                    },
-                    {
-                        "value": "associated",
-                        "name": "associated"
-                    },
-                    {
-                        "value": "disassociating",
-                        "name": "disassociating"
-                    },
-                    {
-                        "value": "disassociated",
-                        "name": "disassociated"
+            "type": "enum",
+            "members": {
+                "associating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associating"
                     }
-                ]
+                },
+                "associated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associated"
+                    }
+                },
+                "disassociating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociating"
+                    }
+                },
+                "disassociated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociated"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayAttachment": {
@@ -76457,6 +81986,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TransitGatewayAsn",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The transit gateway Autonomous System Number (ASN).</p>",
                         "smithy.api#xmlName": "transitGatewayAsn"
                     }
@@ -76465,6 +81996,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PeerAsn",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The peer Autonomous System Number (ASN).</p>",
                         "smithy.api#xmlName": "peerAsn"
                     }
@@ -76559,93 +82092,127 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayAttachmentResourceType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "vpc",
-                        "name": "vpc"
-                    },
-                    {
-                        "value": "vpn",
-                        "name": "vpn"
-                    },
-                    {
-                        "value": "direct-connect-gateway",
-                        "name": "direct_connect_gateway"
-                    },
-                    {
-                        "value": "connect",
-                        "name": "connect"
-                    },
-                    {
-                        "value": "peering",
-                        "name": "peering"
-                    },
-                    {
-                        "value": "tgw-peering",
-                        "name": "tgw_peering"
+            "type": "enum",
+            "members": {
+                "vpc": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vpc"
                     }
-                ]
+                },
+                "vpn": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "vpn"
+                    }
+                },
+                "direct_connect_gateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "direct-connect-gateway"
+                    }
+                },
+                "connect": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "connect"
+                    }
+                },
+                "peering": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "peering"
+                    }
+                },
+                "tgw_peering": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "tgw-peering"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayAttachmentState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "initiating",
-                        "name": "initiating"
-                    },
-                    {
-                        "value": "initiatingRequest",
-                        "name": "initiatingRequest"
-                    },
-                    {
-                        "value": "pendingAcceptance",
-                        "name": "pendingAcceptance"
-                    },
-                    {
-                        "value": "rollingBack",
-                        "name": "rollingBack"
-                    },
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "modifying",
-                        "name": "modifying"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
-                    },
-                    {
-                        "value": "rejected",
-                        "name": "rejected"
-                    },
-                    {
-                        "value": "rejecting",
-                        "name": "rejecting"
-                    },
-                    {
-                        "value": "failing",
-                        "name": "failing"
+            "type": "enum",
+            "members": {
+                "initiating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "initiating"
                     }
-                ]
+                },
+                "initiatingRequest": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "initiatingRequest"
+                    }
+                },
+                "pendingAcceptance": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pendingAcceptance"
+                    }
+                },
+                "rollingBack": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "rollingBack"
+                    }
+                },
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
+                    }
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "modifying": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modifying"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "rejected": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "rejected"
+                    }
+                },
+                "rejecting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "rejecting"
+                    }
+                },
+                "failing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failing"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayCidrBlockStringList": {
@@ -76872,26 +82439,32 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayConnectPeerState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayConnectRequestBgpOptions": {
@@ -76900,6 +82473,8 @@
                 "PeerAsn": {
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The peer Autonomous System Number (ASN).</p>"
                     }
                 }
@@ -76932,6 +82507,7 @@
         "com.amazonaws.ec2#TransitGatewayMaxResults": {
             "type": "integer",
             "traits": {
+                "smithy.api#default": 0,
                 "smithy.api#range": {
                     "min": 5,
                     "max": 1000
@@ -76939,38 +82515,50 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayMulitcastDomainAssociationState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pendingAcceptance",
-                        "name": "pendingAcceptance"
-                    },
-                    {
-                        "value": "associating",
-                        "name": "associating"
-                    },
-                    {
-                        "value": "associated",
-                        "name": "associated"
-                    },
-                    {
-                        "value": "disassociating",
-                        "name": "disassociating"
-                    },
-                    {
-                        "value": "disassociated",
-                        "name": "disassociated"
-                    },
-                    {
-                        "value": "rejected",
-                        "name": "rejected"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
+            "type": "enum",
+            "members": {
+                "pendingAcceptance": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pendingAcceptance"
                     }
-                ]
+                },
+                "associating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associating"
+                    }
+                },
+                "associated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associated"
+                    }
+                },
+                "disassociating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociating"
+                    }
+                },
+                "disassociated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociated"
+                    }
+                },
+                "rejected": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "rejected"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayMulticastDeregisteredGroupMembers": {
@@ -77276,26 +82864,32 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayMulticastDomainState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayMulticastGroup": {
@@ -77361,6 +82955,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "GroupMember",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates that the resource is a  transit gateway multicast group member.</p>",
                         "smithy.api#xmlName": "groupMember"
                     }
@@ -77369,6 +82965,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "GroupSource",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates that the resource is a  transit gateway multicast group member.</p>",
                         "smithy.api#xmlName": "groupSource"
                     }
@@ -77483,6 +83081,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AmazonSideAsn",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>A private Autonomous System Number (ASN) for the Amazon side of a BGP session. \n         The range is 64512 to 65534 for 16-bit ASNs and 4200000000 to 4294967294 for 32-bit ASNs.</p>",
                         "smithy.api#xmlName": "amazonSideAsn"
                     }
@@ -77917,26 +83517,32 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayPolicyTableState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayPrefixListAttachment": {
@@ -78010,6 +83616,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Blackhole",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether traffic that matches this route is dropped.</p>",
                         "smithy.api#xmlName": "blackhole"
                     }
@@ -78037,26 +83645,32 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayPrefixListReferenceState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "modifying",
-                        "name": "modifying"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "modifying": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modifying"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayPropagation": {
@@ -78116,26 +83730,32 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayPropagationState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enabling",
-                        "name": "enabling"
-                    },
-                    {
-                        "value": "enabled",
-                        "name": "enabled"
-                    },
-                    {
-                        "value": "disabling",
-                        "name": "disabling"
-                    },
-                    {
-                        "value": "disabled",
-                        "name": "disabled"
+            "type": "enum",
+            "members": {
+                "enabling": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabling"
                     }
-                ]
+                },
+                "enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enabled"
+                    }
+                },
+                "disabling": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabling"
+                    }
+                },
+                "disabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disabled"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayRequestOptions": {
@@ -78144,6 +83764,8 @@
                 "AmazonSideAsn": {
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>A private Autonomous System Number (ASN) for the Amazon side of a BGP session. \n         The range is 64512 to 65534 for 16-bit ASNs and 4200000000 to 4294967294 for 32-bit ASNs. The default is <code>64512</code>.</p>"
                     }
                 },
@@ -78301,30 +83923,38 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayRouteState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "blackhole",
-                        "name": "blackhole"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "blackhole": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "blackhole"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayRouteTable": {
@@ -78358,6 +83988,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DefaultAssociationRouteTable",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether this is the default association route table for the transit gateway.</p>",
                         "smithy.api#xmlName": "defaultAssociationRouteTable"
                     }
@@ -78366,6 +83998,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DefaultPropagationRouteTable",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether this is the default propagation route table for the transit gateway.</p>",
                         "smithy.api#xmlName": "defaultPropagationRouteTable"
                     }
@@ -78488,18 +84122,20 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayRouteTableAnnouncementDirection": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "outgoing",
-                        "name": "outgoing"
-                    },
-                    {
-                        "value": "incoming",
-                        "name": "incoming"
+            "type": "enum",
+            "members": {
+                "outgoing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "outgoing"
                     }
-                ]
+                },
+                "incoming": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "incoming"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayRouteTableAnnouncementId": {
@@ -78524,34 +84160,44 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayRouteTableAnnouncementState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "failing",
-                        "name": "failing"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
                     }
-                ]
+                },
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
+                    }
+                },
+                "failing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failing"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayRouteTableAssociation": {
@@ -78746,68 +84392,84 @@
             }
         },
         "com.amazonaws.ec2#TransitGatewayRouteTableState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayRouteType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "static",
-                        "name": "static"
-                    },
-                    {
-                        "value": "propagated",
-                        "name": "propagated"
+            "type": "enum",
+            "members": {
+                "static": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "static"
                     }
-                ]
+                },
+                "propagated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "propagated"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewayState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "modifying",
-                        "name": "modifying"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "modifying": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modifying"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TransitGatewaySubnetIdList": {
@@ -78941,18 +84603,20 @@
             }
         },
         "com.amazonaws.ec2#TransportProtocol": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "tcp",
-                        "name": "tcp"
-                    },
-                    {
-                        "value": "udp",
-                        "name": "udp"
+            "type": "enum",
+            "members": {
+                "tcp": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "tcp"
                     }
-                ]
+                },
+                "udp": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "udp"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TrunkInterfaceAssociation": {
@@ -78994,6 +84658,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "VlanId",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The ID of the VLAN when you use the VLAN protocol.</p>",
                         "smithy.api#xmlName": "vlanId"
                     }
@@ -79002,6 +84668,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "GreKey",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The application key when you use the GRE protocol.</p>",
                         "smithy.api#xmlName": "greKey"
                     }
@@ -79041,18 +84709,20 @@
             }
         },
         "com.amazonaws.ec2#TunnelInsideIpVersion": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ipv4",
-                        "name": "ipv4"
-                    },
-                    {
-                        "value": "ipv6",
-                        "name": "ipv6"
+            "type": "enum",
+            "members": {
+                "ipv4": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv4"
                     }
-                ]
+                },
+                "ipv6": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ipv6"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#TunnelOption": {
@@ -79094,6 +84764,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Phase1LifetimeSeconds",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The lifetime for phase 1 of the IKE negotiation, in seconds.</p>",
                         "smithy.api#xmlName": "phase1LifetimeSeconds"
                     }
@@ -79102,6 +84774,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Phase2LifetimeSeconds",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The lifetime for phase 2 of the IKE negotiation, in seconds.</p>",
                         "smithy.api#xmlName": "phase2LifetimeSeconds"
                     }
@@ -79110,6 +84784,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RekeyMarginTimeSeconds",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The margin time, in seconds, before the phase 2 lifetime expires, during which the\n                Amazon Web Services side of the VPN connection performs an IKE rekey.</p>",
                         "smithy.api#xmlName": "rekeyMarginTimeSeconds"
                     }
@@ -79118,6 +84794,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RekeyFuzzPercentage",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The percentage of the rekey window determined by <code>RekeyMarginTimeSeconds</code>\n            during which the rekey time is randomly selected.</p>",
                         "smithy.api#xmlName": "rekeyFuzzPercentage"
                     }
@@ -79126,6 +84804,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ReplayWindowSize",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of packets in an IKE replay window.</p>",
                         "smithy.api#xmlName": "replayWindowSize"
                     }
@@ -79134,6 +84814,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DpdTimeoutSeconds",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of seconds after which a DPD timeout occurs.</p>",
                         "smithy.api#xmlName": "dpdTimeoutSeconds"
                     }
@@ -79266,6 +84948,7 @@
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkInterfaceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network interface.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkInterfaceId"
@@ -79321,6 +85004,7 @@
                     "target": "com.amazonaws.ec2#NetworkInterfaceId",
                     "traits": {
                         "aws.protocols#ec2QueryName": "NetworkInterfaceId",
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The ID of the network interface.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "networkInterfaceId"
@@ -79347,26 +85031,32 @@
             }
         },
         "com.amazonaws.ec2#UnlimitedSupportedInstanceFamily": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "t2",
-                        "name": "t2"
-                    },
-                    {
-                        "value": "t3",
-                        "name": "t3"
-                    },
-                    {
-                        "value": "t3a",
-                        "name": "t3a"
-                    },
-                    {
-                        "value": "t4g",
-                        "name": "t4g"
+            "type": "enum",
+            "members": {
+                "t2": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "t2"
                     }
-                ]
+                },
+                "t3": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "t3"
+                    }
+                },
+                "t3a": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "t3a"
+                    }
+                },
+                "t4g": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "t4g"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#UnmonitorInstances": {
@@ -79387,6 +85077,7 @@
                 "InstanceIds": {
                     "target": "com.amazonaws.ec2#InstanceIdStringList",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The IDs of the instances.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "InstanceId"
@@ -79396,6 +85087,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DryRun",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>",
                         "smithy.api#xmlName": "dryRun"
                     }
@@ -79416,26 +85109,32 @@
             }
         },
         "com.amazonaws.ec2#UnsuccessfulInstanceCreditSpecificationErrorCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "InvalidInstanceID.Malformed",
-                        "name": "INVALID_INSTANCE_ID"
-                    },
-                    {
-                        "value": "InvalidInstanceID.NotFound",
-                        "name": "INSTANCE_NOT_FOUND"
-                    },
-                    {
-                        "value": "IncorrectInstanceState",
-                        "name": "INCORRECT_INSTANCE_STATE"
-                    },
-                    {
-                        "value": "InstanceCreditSpecification.NotSupported",
-                        "name": "INSTANCE_CREDIT_SPECIFICATION_NOT_SUPPORTED"
+            "type": "enum",
+            "members": {
+                "INVALID_INSTANCE_ID": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "InvalidInstanceID.Malformed"
                     }
-                ]
+                },
+                "INSTANCE_NOT_FOUND": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "InvalidInstanceID.NotFound"
+                    }
+                },
+                "INCORRECT_INSTANCE_STATE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "IncorrectInstanceState"
+                    }
+                },
+                "INSTANCE_CREDIT_SPECIFICATION_NOT_SUPPORTED": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "InstanceCreditSpecification.NotSupported"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#UnsuccessfulInstanceCreditSpecificationItem": {
@@ -79579,6 +85278,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -79616,6 +85317,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -79640,6 +85343,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 },
@@ -79677,6 +85382,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Return",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Returns <code>true</code> if the request succeeds; otherwise, returns an error.</p>",
                         "smithy.api#xmlName": "return"
                     }
@@ -79684,18 +85391,20 @@
             }
         },
         "com.amazonaws.ec2#UsageClassType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "spot",
-                        "name": "spot"
-                    },
-                    {
-                        "value": "on-demand",
-                        "name": "on_demand"
+            "type": "enum",
+            "members": {
+                "spot": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "spot"
                     }
-                ]
+                },
+                "on_demand": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "on-demand"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#UsageClassTypeList": {
@@ -79869,10 +85578,7 @@
             }
         },
         "com.amazonaws.ec2#VCpuCount": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#VCpuCountRange": {
             "type": "structure",
@@ -79881,6 +85587,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Min",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum number of vCPUs. If the value is <code>0</code>, there is no minimum\n         limit.</p>",
                         "smithy.api#xmlName": "min"
                     }
@@ -79889,6 +85597,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Max",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of vCPUs. If this parameter is not specified, there is no maximum\n         limit.</p>",
                         "smithy.api#xmlName": "max"
                     }
@@ -79904,6 +85614,8 @@
                 "Min": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The minimum number of vCPUs. To specify no minimum limit, specify <code>0</code>.</p>",
                         "smithy.api#required": {}
                     }
@@ -79911,6 +85623,8 @@
                 "Max": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The maximum number of vCPUs. To specify no maximum limit, omit this parameter.</p>"
                     }
                 }
@@ -80041,6 +85755,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AcceptedRouteCount",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of accepted routes.</p>",
                         "smithy.api#xmlName": "acceptedRouteCount"
                     }
@@ -80100,18 +85816,20 @@
             }
         },
         "com.amazonaws.ec2#VirtualizationType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "hvm",
-                        "name": "hvm"
-                    },
-                    {
-                        "value": "paravirtual",
-                        "name": "paravirtual"
+            "type": "enum",
+            "members": {
+                "hvm": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "hvm"
                     }
-                ]
+                },
+                "paravirtual": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "paravirtual"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VirtualizationTypeList": {
@@ -80169,6 +85887,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Encrypted",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the volume is encrypted.</p>",
                         "smithy.api#xmlName": "encrypted"
                     }
@@ -80193,6 +85913,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Size",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the volume, in GiBs.</p>",
                         "smithy.api#xmlName": "size"
                     }
@@ -80225,6 +85947,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Iops",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of I/O operations per second (IOPS). For <code>gp3</code>, <code>io1</code>, and <code>io2</code> volumes, this represents \n      the number of IOPS that are provisioned for the volume. For <code>gp2</code> volumes, this represents the baseline \n      performance of the volume and the rate at which the volume accumulates I/O credits for bursting.</p>",
                         "smithy.api#xmlName": "iops"
                     }
@@ -80249,6 +85973,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "FastRestored",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the volume was created using fast snapshot restore.</p>",
                         "smithy.api#xmlName": "fastRestored"
                     }
@@ -80257,6 +85983,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "MultiAttachEnabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether Amazon EBS Multi-Attach is enabled.</p>",
                         "smithy.api#xmlName": "multiAttachEnabled"
                     }
@@ -80265,6 +85993,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Throughput",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The throughput that the volume supports, in MiB/s.</p>",
                         "smithy.api#xmlName": "throughput"
                     }
@@ -80321,6 +86051,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "DeleteOnTermination",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the EBS volume is deleted on instance termination.</p>",
                         "smithy.api#xmlName": "deleteOnTermination"
                     }
@@ -80340,45 +86072,55 @@
             }
         },
         "com.amazonaws.ec2#VolumeAttachmentState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "attaching",
-                        "name": "attaching"
-                    },
-                    {
-                        "value": "attached",
-                        "name": "attached"
-                    },
-                    {
-                        "value": "detaching",
-                        "name": "detaching"
-                    },
-                    {
-                        "value": "detached",
-                        "name": "detached"
-                    },
-                    {
-                        "value": "busy",
-                        "name": "busy"
+            "type": "enum",
+            "members": {
+                "attaching": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "attaching"
                     }
-                ]
+                },
+                "attached": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "attached"
+                    }
+                },
+                "detaching": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "detaching"
+                    }
+                },
+                "detached": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "detached"
+                    }
+                },
+                "busy": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "busy"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VolumeAttributeName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "autoEnableIO",
-                        "name": "autoEnableIO"
-                    },
-                    {
-                        "value": "productCodes",
-                        "name": "productCodes"
+            "type": "enum",
+            "members": {
+                "autoEnableIO": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "autoEnableIO"
                     }
-                ]
+                },
+                "productCodes": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "productCodes"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VolumeDetail": {
@@ -80388,6 +86130,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Size",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The size of the volume, in GiB.</p>",
                         "smithy.api#required": {},
                         "smithy.api#xmlName": "size"
@@ -80450,6 +86194,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TargetSize",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The target size of the volume, in GiB.</p>",
                         "smithy.api#xmlName": "targetSize"
                     }
@@ -80458,6 +86204,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TargetIops",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The target IOPS rate of the volume.</p>",
                         "smithy.api#xmlName": "targetIops"
                     }
@@ -80474,6 +86222,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TargetThroughput",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The target throughput of the volume, in MiB/s.</p>",
                         "smithy.api#xmlName": "targetThroughput"
                     }
@@ -80482,6 +86232,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "TargetMultiAttachEnabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>The target setting for Amazon EBS Multi-Attach.</p>",
                         "smithy.api#xmlName": "targetMultiAttachEnabled"
                     }
@@ -80490,6 +86242,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "OriginalSize",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The original size of the volume, in GiB.</p>",
                         "smithy.api#xmlName": "originalSize"
                     }
@@ -80498,6 +86252,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "OriginalIops",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The original IOPS rate of the volume.</p>",
                         "smithy.api#xmlName": "originalIops"
                     }
@@ -80514,6 +86270,8 @@
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
                         "aws.protocols#ec2QueryName": "OriginalThroughput",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The original throughput of the volume, in MiB/s.</p>",
                         "smithy.api#xmlName": "originalThroughput"
                     }
@@ -80522,6 +86280,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "OriginalMultiAttachEnabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>The original setting for Amazon EBS Multi-Attach.</p>",
                         "smithy.api#xmlName": "originalMultiAttachEnabled"
                     }
@@ -80530,6 +86290,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "Progress",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The modification progress, from 0 to 100 percent complete.</p>",
                         "smithy.api#xmlName": "progress"
                     }
@@ -80565,57 +86327,73 @@
             }
         },
         "com.amazonaws.ec2#VolumeModificationState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "modifying",
-                        "name": "modifying"
-                    },
-                    {
-                        "value": "optimizing",
-                        "name": "optimizing"
-                    },
-                    {
-                        "value": "completed",
-                        "name": "completed"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
+            "type": "enum",
+            "members": {
+                "modifying": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "modifying"
                     }
-                ]
+                },
+                "optimizing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "optimizing"
+                    }
+                },
+                "completed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "completed"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VolumeState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "creating",
-                        "name": "creating"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "in-use",
-                        "name": "in_use"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
-                    },
-                    {
-                        "value": "error",
-                        "name": "error"
+            "type": "enum",
+            "members": {
+                "creating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "creating"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "in_use": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "in-use"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                },
+                "error": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "error"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VolumeStatusAction": {
@@ -80823,22 +86601,26 @@
             }
         },
         "com.amazonaws.ec2#VolumeStatusInfoStatus": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "ok",
-                        "name": "ok"
-                    },
-                    {
-                        "value": "impaired",
-                        "name": "impaired"
-                    },
-                    {
-                        "value": "insufficient-data",
-                        "name": "insufficient_data"
+            "type": "enum",
+            "members": {
+                "ok": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "ok"
                     }
-                ]
+                },
+                "impaired": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "impaired"
+                    }
+                },
+                "insufficient_data": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "insufficient-data"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VolumeStatusItem": {
@@ -80915,53 +86697,67 @@
             }
         },
         "com.amazonaws.ec2#VolumeStatusName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "io-enabled",
-                        "name": "io_enabled"
-                    },
-                    {
-                        "value": "io-performance",
-                        "name": "io_performance"
+            "type": "enum",
+            "members": {
+                "io_enabled": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "io-enabled"
                     }
-                ]
+                },
+                "io_performance": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "io-performance"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VolumeType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "standard",
-                        "name": "standard"
-                    },
-                    {
-                        "value": "io1",
-                        "name": "io1"
-                    },
-                    {
-                        "value": "io2",
-                        "name": "io2"
-                    },
-                    {
-                        "value": "gp2",
-                        "name": "gp2"
-                    },
-                    {
-                        "value": "sc1",
-                        "name": "sc1"
-                    },
-                    {
-                        "value": "st1",
-                        "name": "st1"
-                    },
-                    {
-                        "value": "gp3",
-                        "name": "gp3"
+            "type": "enum",
+            "members": {
+                "standard": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "standard"
                     }
-                ]
+                },
+                "io1": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "io1"
+                    }
+                },
+                "io2": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "io2"
+                    }
+                },
+                "gp2": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "gp2"
+                    }
+                },
+                "sc1": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "sc1"
+                    }
+                },
+                "st1": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "st1"
+                    }
+                },
+                "gp3": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "gp3"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#Vpc": {
@@ -81035,6 +86831,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "IsDefault",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the VPC is the default VPC.</p>",
                         "smithy.api#xmlName": "isDefault"
                     }
@@ -81086,18 +86884,20 @@
             }
         },
         "com.amazonaws.ec2#VpcAttributeName": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enableDnsSupport",
-                        "name": "enableDnsSupport"
-                    },
-                    {
-                        "value": "enableDnsHostnames",
-                        "name": "enableDnsHostnames"
+            "type": "enum",
+            "members": {
+                "enableDnsSupport": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enableDnsSupport"
                     }
-                ]
+                },
+                "enableDnsHostnames": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enableDnsHostnames"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VpcCidrAssociationId": {
@@ -81169,34 +86969,44 @@
             }
         },
         "com.amazonaws.ec2#VpcCidrBlockStateCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "associating",
-                        "name": "associating"
-                    },
-                    {
-                        "value": "associated",
-                        "name": "associated"
-                    },
-                    {
-                        "value": "disassociating",
-                        "name": "disassociating"
-                    },
-                    {
-                        "value": "disassociated",
-                        "name": "disassociated"
-                    },
-                    {
-                        "value": "failing",
-                        "name": "failing"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
+            "type": "enum",
+            "members": {
+                "associating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associating"
                     }
-                ]
+                },
+                "associated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "associated"
+                    }
+                },
+                "disassociating": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociating"
+                    }
+                },
+                "disassociated": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disassociated"
+                    }
+                },
+                "failing": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failing"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VpcClassicLink": {
@@ -81206,6 +87016,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "ClassicLinkEnabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the VPC is enabled for ClassicLink.</p>",
                         "smithy.api#xmlName": "classicLinkEnabled"
                     }
@@ -81344,6 +87156,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "PrivateDnsEnabled",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>(Interface endpoint) Indicates whether the VPC is associated with a private hosted zone.</p>",
                         "smithy.api#xmlName": "privateDnsEnabled"
                     }
@@ -81352,6 +87166,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "RequesterManaged",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the endpoint is being managed by its service.</p>",
                         "smithy.api#xmlName": "requesterManaged"
                     }
@@ -81483,6 +87299,22 @@
                         "smithy.api#documentation": "<p>The IP address type for the endpoint.</p>",
                         "smithy.api#xmlName": "ipAddressType"
                     }
+                },
+                "VpcEndpointConnectionId": {
+                    "target": "com.amazonaws.ec2#String",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "VpcEndpointConnectionId",
+                        "smithy.api#documentation": "<p>The ID of the VPC endpoint connection.</p>",
+                        "smithy.api#xmlName": "vpcEndpointConnectionId"
+                    }
+                },
+                "Tags": {
+                    "target": "com.amazonaws.ec2#TagList",
+                    "traits": {
+                        "aws.protocols#ec2QueryName": "TagSet",
+                        "smithy.api#documentation": "<p>The tags.</p>",
+                        "smithy.api#xmlName": "tagSet"
+                    }
                 }
             },
             "traits": {
@@ -81559,22 +87391,26 @@
             }
         },
         "com.amazonaws.ec2#VpcEndpointType": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Interface",
-                        "name": "Interface"
-                    },
-                    {
-                        "value": "Gateway",
-                        "name": "Gateway"
-                    },
-                    {
-                        "value": "GatewayLoadBalancer",
-                        "name": "GatewayLoadBalancer"
+            "type": "enum",
+            "members": {
+                "Interface": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Interface"
                     }
-                ]
+                },
+                "Gateway": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Gateway"
+                    }
+                },
+                "GatewayLoadBalancer": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "GatewayLoadBalancer"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VpcFlowLogId": {
@@ -81742,6 +87578,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AllowDnsResolutionFromRemoteVpc",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether a local VPC can resolve public DNS hostnames to private IP addresses when queried from instances in a peer VPC.</p>",
                         "smithy.api#xmlName": "allowDnsResolutionFromRemoteVpc"
                     }
@@ -81750,6 +87588,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AllowEgressFromLocalClassicLinkToRemoteVpc",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether a local ClassicLink connection can communicate with the peer VPC over the VPC peering connection.</p>",
                         "smithy.api#xmlName": "allowEgressFromLocalClassicLinkToRemoteVpc"
                     }
@@ -81758,6 +87598,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AllowEgressFromLocalVpcToRemoteClassicLink",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether a local VPC can communicate with a ClassicLink connection in the peer VPC over the VPC peering connection.</p>",
                         "smithy.api#xmlName": "allowEgressFromLocalVpcToRemoteClassicLink"
                     }
@@ -81792,46 +87634,62 @@
             }
         },
         "com.amazonaws.ec2#VpcPeeringConnectionStateReasonCode": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "initiating-request",
-                        "name": "initiating_request"
-                    },
-                    {
-                        "value": "pending-acceptance",
-                        "name": "pending_acceptance"
-                    },
-                    {
-                        "value": "active",
-                        "name": "active"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
-                    },
-                    {
-                        "value": "rejected",
-                        "name": "rejected"
-                    },
-                    {
-                        "value": "failed",
-                        "name": "failed"
-                    },
-                    {
-                        "value": "expired",
-                        "name": "expired"
-                    },
-                    {
-                        "value": "provisioning",
-                        "name": "provisioning"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
+            "type": "enum",
+            "members": {
+                "initiating_request": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "initiating-request"
                     }
-                ]
+                },
+                "pending_acceptance": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending-acceptance"
+                    }
+                },
+                "active": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "active"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                },
+                "rejected": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "rejected"
+                    }
+                },
+                "failed": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "failed"
+                    }
+                },
+                "expired": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "expired"
+                    }
+                },
+                "provisioning": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "provisioning"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VpcPeeringConnectionVpcInfo": {
@@ -81899,29 +87757,31 @@
             }
         },
         "com.amazonaws.ec2#VpcState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VpcTenancy": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "default",
-                        "name": "default"
+            "type": "enum",
+            "members": {
+                "default": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "default"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#VpnConnection": {
@@ -82138,6 +87998,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "EnableAcceleration",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether acceleration is enabled for the VPN connection.</p>",
                         "smithy.api#xmlName": "enableAcceleration"
                     }
@@ -82146,6 +88008,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "StaticRoutesOnly",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicates whether the VPN connection uses static routes only. Static routes must be\n            used for devices that don't support BGP.</p>",
                         "smithy.api#xmlName": "staticRoutesOnly"
                     }
@@ -82225,6 +88089,8 @@
                 "EnableAcceleration": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicate whether to enable acceleration for the VPN connection.</p>\n        <p>Default: <code>false</code>\n         </p>"
                     }
                 },
@@ -82232,6 +88098,8 @@
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
                         "aws.protocols#ec2QueryName": "StaticRoutesOnly",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Indicate whether the VPN connection uses static routes only. If you are creating a VPN\n            connection for a device that does not support BGP, you must specify <code>true</code>.\n            Use <a>CreateVpnConnectionRoute</a> to create a static route.</p>\n        <p>Default: <code>false</code>\n         </p>",
                         "smithy.api#xmlName": "staticRoutesOnly"
                     }
@@ -82290,18 +88158,20 @@
             }
         },
         "com.amazonaws.ec2#VpnEcmpSupportValue": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "enable",
-                        "name": "enable"
-                    },
-                    {
-                        "value": "disable",
-                        "name": "disable"
+            "type": "enum",
+            "members": {
+                "enable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "enable"
                     }
-                ]
+                },
+                "disable": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "disable"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VpnGateway": {
@@ -82351,6 +88221,8 @@
                     "target": "com.amazonaws.ec2#Long",
                     "traits": {
                         "aws.protocols#ec2QueryName": "AmazonSideAsn",
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The private Autonomous System Number (ASN) for the Amazon side of a BGP\n            session.</p>",
                         "smithy.api#xmlName": "amazonSideAsn"
                     }
@@ -82390,37 +88262,43 @@
             }
         },
         "com.amazonaws.ec2#VpnProtocol": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "openvpn",
-                        "name": "openvpn"
+            "type": "enum",
+            "members": {
+                "openvpn": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "openvpn"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#VpnState": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "pending",
-                        "name": "pending"
-                    },
-                    {
-                        "value": "available",
-                        "name": "available"
-                    },
-                    {
-                        "value": "deleting",
-                        "name": "deleting"
-                    },
-                    {
-                        "value": "deleted",
-                        "name": "deleted"
+            "type": "enum",
+            "members": {
+                "pending": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "pending"
                     }
-                ]
+                },
+                "available": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "available"
+                    }
+                },
+                "deleting": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleting"
+                    }
+                },
+                "deleted": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "deleted"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#VpnStaticRoute": {
@@ -82465,14 +88343,14 @@
             }
         },
         "com.amazonaws.ec2#VpnStaticRouteSource": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Static",
-                        "name": "Static"
+            "type": "enum",
+            "members": {
+                "Static": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Static"
                     }
-                ]
+                }
             }
         },
         "com.amazonaws.ec2#VpnTunnelLogOptions": {
@@ -82529,36 +88407,48 @@
                 "Phase1LifetimeSeconds": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The lifetime for phase 1 of the IKE negotiation, in seconds.</p>\n        <p>Constraints: A value between 900 and 28,800.</p>\n        <p>Default: <code>28800</code>\n         </p>"
                     }
                 },
                 "Phase2LifetimeSeconds": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The lifetime for phase 2 of the IKE negotiation, in seconds.</p>\n        <p>Constraints: A value between 900 and 3,600. The value must be less than the value for\n                <code>Phase1LifetimeSeconds</code>.</p>\n        <p>Default: <code>3600</code>\n         </p>"
                     }
                 },
                 "RekeyMarginTimeSeconds": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The margin time, in seconds, before the phase 2 lifetime expires, during which the\n                Amazon Web Services side of the VPN connection performs an IKE rekey. The exact time\n            of the rekey is randomly selected based on the value for\n                <code>RekeyFuzzPercentage</code>.</p>\n        <p>Constraints: A value between 60 and half of <code>Phase2LifetimeSeconds</code>.</p>\n        <p>Default: <code>540</code>\n         </p>"
                     }
                 },
                 "RekeyFuzzPercentage": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The percentage of the rekey window (determined by <code>RekeyMarginTimeSeconds</code>)\n            during which the rekey time is randomly selected.</p>\n        <p>Constraints: A value between 0 and 100.</p>\n        <p>Default: <code>100</code>\n         </p>"
                     }
                 },
                 "ReplayWindowSize": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of packets in an IKE replay window.</p>\n        <p>Constraints: A value between 64 and 2048.</p>\n        <p>Default: <code>1024</code>\n         </p>"
                     }
                 },
                 "DPDTimeoutSeconds": {
                     "target": "com.amazonaws.ec2#Integer",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": 0,
                         "smithy.api#documentation": "<p>The number of seconds after which a DPD timeout occurs.</p>\n        <p>Constraints: A value greater than or equal to 30.</p>\n        <p>Default: <code>30</code>\n         </p>"
                     }
                 },
@@ -82641,38 +88531,50 @@
             }
         },
         "com.amazonaws.ec2#WeekDay": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "sunday",
-                        "name": "sunday"
-                    },
-                    {
-                        "value": "monday",
-                        "name": "monday"
-                    },
-                    {
-                        "value": "tuesday",
-                        "name": "tuesday"
-                    },
-                    {
-                        "value": "wednesday",
-                        "name": "wednesday"
-                    },
-                    {
-                        "value": "thursday",
-                        "name": "thursday"
-                    },
-                    {
-                        "value": "friday",
-                        "name": "friday"
-                    },
-                    {
-                        "value": "saturday",
-                        "name": "saturday"
+            "type": "enum",
+            "members": {
+                "sunday": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "sunday"
                     }
-                ]
+                },
+                "monday": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "monday"
+                    }
+                },
+                "tuesday": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "tuesday"
+                    }
+                },
+                "wednesday": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "wednesday"
+                    }
+                },
+                "thursday": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "thursday"
+                    }
+                },
+                "friday": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "friday"
+                    }
+                },
+                "saturday": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "saturday"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#WithdrawByoipCidr": {
@@ -82693,6 +88595,7 @@
                 "Cidr": {
                     "target": "com.amazonaws.ec2#String",
                     "traits": {
+                        "smithy.api#clientOptional": {},
                         "smithy.api#documentation": "<p>The address range, in CIDR notation.</p>",
                         "smithy.api#required": {}
                     }
@@ -82700,6 +88603,8 @@
                 "DryRun": {
                     "target": "com.amazonaws.ec2#Boolean",
                     "traits": {
+                        "smithy.api#clientOptional": {},
+                        "smithy.api#default": false,
                         "smithy.api#documentation": "<p>Checks whether you have the required permissions for the action, without actually making the request, \n   and provides an error response. If you have the required permissions, the error response is <code>DryRunOperation</code>. \n   Otherwise, it is <code>UnauthorizedOperation</code>.</p>"
                     }
                 }
@@ -82737,18 +88642,20 @@
             }
         },
         "com.amazonaws.ec2#scope": {
-            "type": "string",
-            "traits": {
-                "smithy.api#enum": [
-                    {
-                        "value": "Availability Zone",
-                        "name": "AVAILABILITY_ZONE"
-                    },
-                    {
-                        "value": "Region",
-                        "name": "REGIONAL"
+            "type": "enum",
+            "members": {
+                "AVAILABILITY_ZONE": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Availability Zone"
                     }
-                ]
+                },
+                "REGIONAL": {
+                    "target": "smithy.api#Unit",
+                    "traits": {
+                        "smithy.api#enumValue": "Region"
+                    }
+                }
             }
         },
         "com.amazonaws.ec2#snapshotTierStatusSet": {
@@ -82761,16 +88668,10 @@
             }
         },
         "com.amazonaws.ec2#totalFpgaMemory": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         },
         "com.amazonaws.ec2#totalGpuMemory": {
-            "type": "integer",
-            "traits": {
-                "smithy.api#box": {}
-            }
+            "type": "integer"
         }
     }
 }
diff --git a/codegen/sdk-codegen/aws-models/sagemaker.json b/codegen/sdk-codegen/aws-models/sagemaker.json
index 5e914385677..3801d88fd52 100644
--- a/codegen/sdk-codegen/aws-models/sagemaker.json
+++ b/codegen/sdk-codegen/aws-models/sagemaker.json
@@ -4618,7 +4618,7 @@
                 }
             ],
             "traits": {
-                "smithy.api#documentation": "<p>Creates a running app for the specified UserProfile. Supported apps are\n      <code>JupyterServer</code> and <code>KernelGateway</code>. This operation is automatically\n      invoked by Amazon SageMaker Studio upon access to the associated Domain, and when new kernel\n      configurations are selected by the user. A user may have multiple Apps active simultaneously.</p>"
+                "smithy.api#documentation": "<p>Creates a running app for the specified UserProfile. This operation is automatically\n      invoked by Amazon SageMaker Studio upon access to the associated Domain, and when new kernel\n      configurations are selected by the user. A user may have multiple Apps active simultaneously.</p>"
             }
         },
         "com.amazonaws.sagemaker#CreateAppImageConfig": {
@@ -4693,7 +4693,7 @@
                 "AppType": {
                     "target": "com.amazonaws.sagemaker#AppType",
                     "traits": {
-                        "smithy.api#documentation": "<p>The type of app. Supported apps are <code>JupyterServer</code> and\n        <code>KernelGateway</code>. <code>TensorBoard</code> is not supported.</p>",
+                        "smithy.api#documentation": "<p>The type of app.</p>",
                         "smithy.api#required": {}
                     }
                 },
@@ -16948,7 +16948,7 @@
                 "ExecutionRoleIdentityConfig": {
                     "target": "com.amazonaws.sagemaker#ExecutionRoleIdentityConfig",
                     "traits": {
-                        "smithy.api#documentation": "<p>The configuration for attaching a SageMaker user profile name to the execution role as a <a href=\"https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_temp_control-access_monitor.html\">\n               <code>sts:SourceIdentity</code> key</a>.</p>"
+                        "smithy.api#documentation": "<p>The configuration for attaching a SageMaker user profile name to the execution role as a <a href=\"https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_temp_control-access_monitor.html\">sts:SourceIdentity key</a>.</p>"
                     }
                 }
             },
@@ -16968,7 +16968,7 @@
                 "ExecutionRoleIdentityConfig": {
                     "target": "com.amazonaws.sagemaker#ExecutionRoleIdentityConfig",
                     "traits": {
-                        "smithy.api#documentation": "<p>The configuration for attaching a SageMaker user profile name to the execution role as a <a href=\"https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_temp_control-access_monitor.html\">\n               <code>sts:SourceIdentity</code> key</a>. This configuration can only be modified if there are no apps in the <code>InService</code> or <code>Pending</code> state.</p>"
+                        "smithy.api#documentation": "<p>The configuration for attaching a SageMaker user profile name to the execution role as a <a href=\"https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_temp_control-access_monitor.html\">sts:SourceIdentity key</a>. This configuration can only be modified if there are no apps in the <code>InService</code> or <code>Pending</code> state.</p>"
                     }
                 }
             },
@@ -20073,7 +20073,7 @@
                 "MaxConcurrentTaskCount": {
                     "target": "com.amazonaws.sagemaker#MaxConcurrentTaskCount",
                     "traits": {
-                        "smithy.api#documentation": "<p>Defines the maximum number of data objects that can be labeled by human workers at the\n            same time. Also referred to as batch size. Each object may have more than one worker at one time.\n            The default value is 1000 objects.</p>"
+                        "smithy.api#documentation": "<p>Defines the maximum number of data objects that can be labeled by human workers at the\n            same time. Also referred to as batch size. Each object may have more than one worker at one time.\n            The default value is 1000 objects. To increase the maximum value to 5000 objects, contact Amazon Web Services Support.</p>"
                     }
                 },
                 "AnnotationConsolidationConfig": {
@@ -20579,10 +20579,16 @@
                 "Strategy": {
                     "target": "com.amazonaws.sagemaker#HyperParameterTuningJobStrategyType",
                     "traits": {
-                        "smithy.api#documentation": "<p>Specifies how hyperparameter tuning chooses the combinations of hyperparameter values\n            to use for the training job it launches. To use the Bayesian search strategy, set this\n            to <code>Bayesian</code>. To randomly search, set it to <code>Random</code>. For\n            information about search strategies, see <a href=\"https://docs.aws.amazon.com/sagemaker/latest/dg/automatic-model-tuning-how-it-works.html\">How\n                Hyperparameter Tuning Works</a>.</p>",
+                        "smithy.api#documentation": "<p>Specifies how hyperparameter tuning chooses the combinations of hyperparameter values\n            to use for the training job it launches. For information about search strategies, see\n                <a href=\"https://docs.aws.amazon.com/sagemaker/latest/dg/automatic-model-tuning-how-it-works.html\">How\n                Hyperparameter Tuning Works</a>.</p>",
                         "smithy.api#required": {}
                     }
                 },
+                "StrategyConfig": {
+                    "target": "com.amazonaws.sagemaker#HyperParameterTuningJobStrategyConfig",
+                    "traits": {
+                        "smithy.api#documentation": "<p>The configuration for the <code>Hyperband</code> optimization strategy. This parameter\n         should be provided only if <code>Hyperband</code> is selected as the strategy for\n            <code>HyperParameterTuningJobConfig</code>.</p>"
+                    }
+                },
                 "HyperParameterTuningJobObjective": {
                     "target": "com.amazonaws.sagemaker#HyperParameterTuningJobObjective",
                     "traits": {
@@ -20605,7 +20611,7 @@
                 "TrainingJobEarlyStoppingType": {
                     "target": "com.amazonaws.sagemaker#TrainingJobEarlyStoppingType",
                     "traits": {
-                        "smithy.api#documentation": "<p>Specifies whether to use early stopping for training jobs launched by the\n            hyperparameter tuning job. This can be one of the following values (the default value is\n                <code>OFF</code>):</p>\n        <dl>\n            <dt>OFF</dt>\n            <dd>\n                    <p>Training jobs launched by the hyperparameter tuning job do not use early\n                        stopping.</p>\n                </dd>\n            <dt>AUTO</dt>\n            <dd>\n                    <p>SageMaker stops training jobs launched by the hyperparameter tuning job when\n                        they are unlikely to perform better than previously completed training jobs.\n                        For more information, see <a href=\"https://docs.aws.amazon.com/sagemaker/latest/dg/automatic-model-tuning-early-stopping.html\">Stop Training Jobs Early</a>.</p>\n                </dd>\n         </dl>"
+                        "smithy.api#documentation": "<p>Specifies whether to use early stopping for training jobs launched by the\n            hyperparameter tuning job. Because the <code>Hyperband</code> strategy has its own\n            advanced internal early stopping mechanism,\n            <code>TrainingJobEarlyStoppingType</code> must be <code>OFF</code> to use <code>Hyperband</code>. This parameter can take on one of the following values (the\n            default value is <code>OFF</code>):</p>\n        <dl>\n            <dt>OFF</dt>\n            <dd>\n                    <p>Training jobs launched by the hyperparameter tuning job do not use early\n                        stopping.</p>\n                </dd>\n            <dt>AUTO</dt>\n            <dd>\n                    <p>SageMaker stops training jobs launched by the hyperparameter tuning job when\n                        they are unlikely to perform better than previously completed training jobs.\n                        For more information, see <a href=\"https://docs.aws.amazon.com/sagemaker/latest/dg/automatic-model-tuning-early-stopping.html\">Stop Training Jobs Early</a>.</p>\n                </dd>\n         </dl>"
                     }
                 },
                 "TuningJobCompletionCriteria": {
@@ -20801,6 +20807,20 @@
                 ]
             }
         },
+        "com.amazonaws.sagemaker#HyperParameterTuningJobStrategyConfig": {
+            "type": "structure",
+            "members": {
+                "HyperbandStrategyConfig": {
+                    "target": "com.amazonaws.sagemaker#HyperbandStrategyConfig",
+                    "traits": {
+                        "smithy.api#documentation": "<p>The configuration for the object that specifies the <code>Hyperband</code> strategy.\n         This parameter is only supported for the <code>Hyperband</code> selection for\n            <code>Strategy</code> within the <code>HyperParameterTuningJobConfig</code> API.</p>"
+                    }
+                }
+            },
+            "traits": {
+                "smithy.api#documentation": "<p>The configuration for a training job launched by a hyperparameter tuning job. Choose\n            <code>Bayesian</code> for Bayesian optimization, and <code>Random</code> for random\n         search optimization. For more advanced use cases, use <code>Hyperband</code>, which\n         evaluates objective metrics for training jobs after every epoch. For more information about\n         strategies, see <a href=\"https://docs.aws.amazon.com/sagemaker/latest/dg/automatic-model-tuning-how-it-works.html\">How Hyperparameter\n            Tuning Works</a>.</p>"
+            }
+        },
         "com.amazonaws.sagemaker#HyperParameterTuningJobStrategyType": {
             "type": "string",
             "traits": {
@@ -20813,6 +20833,10 @@
                     {
                         "value": "Random",
                         "name": "RANDOM"
+                    },
+                    {
+                        "value": "Hyperband",
+                        "name": "HYPERBAND"
                     }
                 ]
             }
@@ -20850,7 +20874,7 @@
                 "Strategy": {
                     "target": "com.amazonaws.sagemaker#HyperParameterTuningJobStrategyType",
                     "traits": {
-                        "smithy.api#documentation": "<p>Specifies the search strategy hyperparameter tuning uses to choose which\n            hyperparameters to\n            use\n            for each iteration. Currently, the only valid value is\n            Bayesian.</p>",
+                        "smithy.api#documentation": "<p>Specifies the search strategy hyperparameter tuning uses to choose which\n            hyperparameters to\n            evaluate\n            at each iteration.</p>",
                         "smithy.api#required": {}
                     }
                 },
@@ -21004,6 +21028,44 @@
                 }
             }
         },
+        "com.amazonaws.sagemaker#HyperbandStrategyConfig": {
+            "type": "structure",
+            "members": {
+                "MinResource": {
+                    "target": "com.amazonaws.sagemaker#HyperbandStrategyMinResource",
+                    "traits": {
+                        "smithy.api#documentation": "<p>The minimum number of resources (such as epochs) that can be used by a training job\n         launched by a hyperparameter tuning job. If the value for <code>MinResource</code> has not\n         been reached, the training job will not be stopped by <code>Hyperband</code>.</p>"
+                    }
+                },
+                "MaxResource": {
+                    "target": "com.amazonaws.sagemaker#HyperbandStrategyMaxResource",
+                    "traits": {
+                        "smithy.api#documentation": "<p>The maximum number of resources (such as epochs) that can be used by a training job\n         launched by a hyperparameter tuning job. Once a job reaches the <code>MaxResource</code>\n         value, it is stopped. If a value for <code>MaxResource</code> is not provided, and\n            <code>Hyperband</code> is selected as the hyperparameter tuning strategy,\n            <code>HyperbandTrainingJ</code> attempts to infer <code>MaxResource</code> from the\n         following keys (if present) in <a href=\"https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_HyperParameterTrainingJobDefinition.html#sagemaker-Type-HyperParameterTrainingJobDefinition-StaticHyperParameters\">StaticsHyperParameters</a>:</p>\n         <ul>\n            <li>\n               <p>\n                  <code>epochs</code>\n               </p>\n            </li>\n            <li>\n               <p>\n                  <code>numepochs</code>\n               </p>\n            </li>\n            <li>\n               <p>\n                  <code>n-epochs</code>\n               </p>\n            </li>\n            <li>\n               <p>\n                  <code>n_epochs</code>\n               </p>\n            </li>\n            <li>\n               <p>\n                  <code>num_epochs</code>\n               </p>\n            </li>\n         </ul>\n         <p>If <code>HyperbandStrategyConfig</code> is unable to infer a value for\n            <code>MaxResource</code>, it generates a validation error. The maximum value is 20,000\n         epochs. All metrics that correspond to an objective metric are used to derive <a href=\"https://docs.aws.amazon.com/sagemaker/latest/dg/automatic-model-tuning-early-stopping.html\">early stopping\n            decisions</a>. For <a href=\"https://docs.aws.amazon.com/sagemaker/latest/dg/distributed-training.html\">distributive</a> training jobs,\n         ensure that duplicate metrics are not printed in the logs across the individual nodes in a\n         training job. If multiple nodes are publishing duplicate or incorrect metrics, training\n         jobs may make an incorrect stopping decision and stop the job prematurely. </p>"
+                    }
+                }
+            },
+            "traits": {
+                "smithy.api#documentation": "<p>The configuration for <code>Hyperband</code>, a multi-fidelity based hyperparameter\n         tuning strategy. <code>Hyperband</code> uses the final and intermediate results of a\n         training job to dynamically allocate resources to utilized hyperparameter configurations\n         while automatically stopping under-performing configurations. This parameter should be\n         provided only if <code>Hyperband</code> is selected as the <code>StrategyConfig</code>\n         under the <code>HyperParameterTuningJobConfig</code> API.</p>"
+            }
+        },
+        "com.amazonaws.sagemaker#HyperbandStrategyMaxResource": {
+            "type": "integer",
+            "traits": {
+                "smithy.api#box": {},
+                "smithy.api#range": {
+                    "min": 1
+                }
+            }
+        },
+        "com.amazonaws.sagemaker#HyperbandStrategyMinResource": {
+            "type": "integer",
+            "traits": {
+                "smithy.api#box": {},
+                "smithy.api#range": {
+                    "min": 1
+                }
+            }
+        },
         "com.amazonaws.sagemaker#IdempotencyToken": {
             "type": "string",
             "traits": {
@@ -28535,7 +28597,7 @@
                 "smithy.api#box": {},
                 "smithy.api#range": {
                     "min": 1,
-                    "max": 1000
+                    "max": 5000
                 }
             }
         },