diff --git a/_api-reference/index-apis/clone.md b/_api-reference/index-apis/clone.md
index 07391ce8f1..bc956eddba 100644
--- a/_api-reference/index-apis/clone.md
+++ b/_api-reference/index-apis/clone.md
@@ -55,6 +55,8 @@ Parameter | Type | Description
 wait_for_active_shards | String | The number of active shards that must be available before OpenSearch processes the request. Default is 1 (only the primary shard). Set to all or a positive integer. Values greater than 1 require replicas. For example, if you specify a value of 3, the index must have two replicas distributed across two additional nodes for the operation to succeed.
 master_timeout | Time | How long to wait for a connection to the master node. Default is `30s`.
 timeout | Time | How long to wait for the request to return. Default is `30s`.
+wait_for_completion | Boolean | When set to `false`, the request returns immediately instead of after the operation is finished. To monitor the operation status, use the [Tasks API]({{site.url}}{{site.baseurl}}/api-reference/tasks/) with the task ID returned by the request. Default is `true`.
+task_execution_timeout | Time | The explicit task execution timeout. Only useful when wait_for_completion is set to `false`. Default is `1h`.
 
 ## Request body
 
diff --git a/_api-reference/index-apis/open-index.md b/_api-reference/index-apis/open-index.md
index 9df21b597c..4097620acd 100644
--- a/_api-reference/index-apis/open-index.md
+++ b/_api-reference/index-apis/open-index.md
@@ -37,6 +37,8 @@ ignore_unavailable | Boolean | If true, OpenSearch does not search for missing o
 wait_for_active_shards | String | Specifies the number of active shards that must be available before OpenSearch processes the request. Default is 1 (only the primary shard). Set to all or a positive integer. Values greater than 1 require replicas. For example, if you specify a value of 3, the index must have two replicas distributed across two additional nodes for the request to succeed.
 master_timeout | Time | How long to wait for a connection to the master node. Default is `30s`.
 timeout | Time | How long to wait for a response from the cluster. Default is `30s`.
+wait_for_completion | Boolean | When set to `false`, the request returns immediately instead of after the operation is finished. To monitor the operation status, use the [Tasks API]({{site.url}}{{site.baseurl}}/api-reference/tasks/) with the task ID returned by the request. Default is `true`.
+task_execution_timeout | Time | The explicit task execution timeout. Only useful when wait_for_completion is set to `false`. Default is `1h`.
 
 
 ## Response
diff --git a/_api-reference/index-apis/shrink-index.md b/_api-reference/index-apis/shrink-index.md
index 1df9269949..851e604094 100644
--- a/_api-reference/index-apis/shrink-index.md
+++ b/_api-reference/index-apis/shrink-index.md
@@ -51,6 +51,8 @@ Parameter | Type | description
 wait_for_active_shards | String | Specifies the number of active shards that must be available before OpenSearch processes the request. Default is 1 (only the primary shard). Set to all or a positive integer. Values greater than 1 require replicas. For example, if you specify a value of 3, the index must have two replicas distributed across two additional nodes for the request to succeed.
 master_timeout | Time | How long to wait for a connection to the master node. Default is `30s`.
 timeout | Time | How long to wait for the request to return a response. Default is `30s`.
+wait_for_completion | Boolean | When set to `false`, the request returns immediately instead of after the operation is finished. To monitor the operation status, use the [Tasks API]({{site.url}}{{site.baseurl}}/api-reference/tasks/) with the task ID returned by the request. Default is `true`.
+task_execution_timeout | Time | The explicit task execution timeout. Only useful when wait_for_completion is set to `false`. Default is `1h`.
 
 ## Request body
 
diff --git a/_api-reference/index-apis/split.md b/_api-reference/index-apis/split.md
index 96032d0915..80a0f9ca35 100644
--- a/_api-reference/index-apis/split.md
+++ b/_api-reference/index-apis/split.md
@@ -55,6 +55,8 @@ Parameter | Type | Description
 wait_for_active_shards | String | The number of active shards that must be available before OpenSearch processes the request. Default is 1 (only the primary shard). Set to all or a positive integer. Values greater than 1 require replicas. For example, if you specify a value of 3, the index must have two replicas distributed across two additional nodes for the operation to succeed.
 master_timeout | Time | How long to wait for a connection to the master node. Default is `30s`.
 timeout | Time | How long to wait for the request to return. Default is `30s`.
+wait_for_completion | Boolean | When set to `false`, the request returns immediately instead of after the operation is finished. To monitor the operation status, use the [Tasks API]({{site.url}}{{site.baseurl}}/api-reference/tasks/) with the task ID returned by the request. Default is `true`.
+task_execution_timeout | Time | The explicit task execution timeout. Only useful when wait_for_completion is set to `false`. Default is `1h`.
 
 ## Request body
 
diff --git a/_im-plugin/ism/policies.md b/_im-plugin/ism/policies.md
index 02a14d8df4..8e873268de 100644
--- a/_im-plugin/ism/policies.md
+++ b/_im-plugin/ism/policies.md
@@ -117,6 +117,8 @@ Reduces the number of Lucene segments by merging the segments of individual shar
 Parameter | Description | Type | Required
 :--- | :--- |:--- |:--- |
 `max_num_segments` | The number of segments to reduce the shard to. | `number` | Yes
+wait_for_completion | Boolean | When set to `false`, the request returns immediately instead of after the operation is finished. To monitor the operation status, use the [Tasks API]({{site.url}}{{site.baseurl}}/api-reference/tasks/) with the task ID returned by the request. Default is `true`.
+task_execution_timeout | Time | The explicit task execution timeout. Only useful when wait_for_completion is set to `false`. Default is `1h`. | No
 
 ```json
 {