diff --git a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/EnvironmentProto.java b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/EnvironmentProto.java
index 8b2a267d7..81960338e 100644
--- a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/EnvironmentProto.java
+++ b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/EnvironmentProto.java
@@ -122,154 +122,156 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
           + "\032\027google/api/client.proto\032\037google/api/fi"
           + "eld_behavior.proto\032\031google/api/resource."
           + "proto\0322google/cloud/dialogflow/cx/v3beta"
-          + "1/test_case.proto\032#google/longrunning/op"
-          + "erations.proto\032\033google/protobuf/empty.pr"
-          + "oto\032 google/protobuf/field_mask.proto\032\037g"
-          + "oogle/protobuf/timestamp.proto\"\230\005\n\013Envir"
-          + "onment\022\014\n\004name\030\001 \001(\t\022\031\n\014display_name\030\002 \001"
-          + "(\tB\003\340A\002\022\023\n\013description\030\003 \001(\t\022[\n\017version_"
-          + "configs\030\006 \003(\0132=.google.cloud.dialogflow."
-          + "cx.v3beta1.Environment.VersionConfigB\003\340A"
-          + "\002\0224\n\013update_time\030\005 \001(\0132\032.google.protobuf"
-          + ".TimestampB\003\340A\003\022Z\n\021test_cases_config\030\007 \001"
-          + "(\0132?.google.cloud.dialogflow.cx.v3beta1."
-          + "Environment.TestCasesConfig\032K\n\rVersionCo"
-          + "nfig\022:\n\007version\030\001 \001(\tB)\340A\002\372A#\n!dialogflo"
-          + "w.googleapis.com/Version\032\217\001\n\017TestCasesCo"
-          + "nfig\022;\n\ntest_cases\030\001 \003(\tB\'\372A$\n\"dialogflo"
-          + "w.googleapis.com/TestCase\022\035\n\025enable_cont"
-          + "inuous_run\030\002 \001(\010\022 \n\030enable_predeployment"
-          + "_run\030\003 \001(\010:}\352Az\n%dialogflow.googleapis.c"
-          + "om/Environment\022Qprojects/{project}/locat"
-          + "ions/{location}/agents/{agent}/environme"
-          + "nts/{environment}\"\177\n\027ListEnvironmentsReq"
-          + "uest\022=\n\006parent\030\001 \001(\tB-\340A\002\372A\'\022%dialogflow"
-          + ".googleapis.com/Environment\022\021\n\tpage_size"
-          + "\030\002 \001(\005\022\022\n\npage_token\030\003 \001(\t\"z\n\030ListEnviro"
-          + "nmentsResponse\022E\n\014environments\030\001 \003(\0132/.g"
-          + "oogle.cloud.dialogflow.cx.v3beta1.Enviro"
-          + "nment\022\027\n\017next_page_token\030\002 \001(\t\"T\n\025GetEnv"
-          + "ironmentRequest\022;\n\004name\030\001 \001(\tB-\340A\002\372A\'\n%d"
-          + "ialogflow.googleapis.com/Environment\"\244\001\n"
-          + "\030CreateEnvironmentRequest\022=\n\006parent\030\001 \001("
-          + "\tB-\340A\002\372A\'\022%dialogflow.googleapis.com/Env"
-          + "ironment\022I\n\013environment\030\002 \001(\0132/.google.c"
-          + "loud.dialogflow.cx.v3beta1.EnvironmentB\003"
-          + "\340A\002\"\233\001\n\030UpdateEnvironmentRequest\022I\n\013envi"
-          + "ronment\030\001 \001(\0132/.google.cloud.dialogflow."
-          + "cx.v3beta1.EnvironmentB\003\340A\002\0224\n\013update_ma"
-          + "sk\030\002 \001(\0132\032.google.protobuf.FieldMaskB\003\340A"
-          + "\002\"W\n\030DeleteEnvironmentRequest\022;\n\004name\030\001 "
-          + "\001(\tB-\340A\002\372A\'\n%dialogflow.googleapis.com/E"
-          + "nvironment\"\205\001\n\037LookupEnvironmentHistoryR"
-          + "equest\022;\n\004name\030\001 \001(\tB-\340A\002\372A\'\n%dialogflow"
-          + ".googleapis.com/Environment\022\021\n\tpage_size"
-          + "\030\002 \001(\005\022\022\n\npage_token\030\003 \001(\t\"\202\001\n LookupEnv"
-          + "ironmentHistoryResponse\022E\n\014environments\030"
-          + "\001 \003(\0132/.google.cloud.dialogflow.cx.v3bet"
-          + "a1.Environment\022\027\n\017next_page_token\030\002 \001(\t\""
-          + "\215\004\n\024ContinuousTestResult\022\014\n\004name\030\001 \001(\t\022]"
-          + "\n\006result\030\002 \001(\0162M.google.cloud.dialogflow"
-          + ".cx.v3beta1.ContinuousTestResult.Aggrega"
-          + "tedTestResult\022H\n\021test_case_results\030\003 \003(\t"
-          + "B-\372A*\n(dialogflow.googleapis.com/TestCas"
-          + "eResult\022,\n\010run_time\030\004 \001(\0132\032.google.proto"
-          + "buf.Timestamp\"V\n\024AggregatedTestResult\022&\n"
-          + "\"AGGREGATED_TEST_RESULT_UNSPECIFIED\020\000\022\n\n"
-          + "\006PASSED\020\001\022\n\n\006FAILED\020\002:\267\001\352A\263\001\n.dialogflow"
-          + ".googleapis.com/ContinuousTestResult\022\200\001p"
-          + "rojects/{project}/locations/{location}/a"
-          + "gents/{agent}/environments/{environment}"
-          + "/continuousTestResults/{continuous_test_"
-          + "result}\"^\n\030RunContinuousTestRequest\022B\n\013e"
-          + "nvironment\030\001 \001(\tB-\340A\002\372A\'\n%dialogflow.goo"
-          + "gleapis.com/Environment\"u\n\031RunContinuous"
-          + "TestResponse\022X\n\026continuous_test_result\030\001"
-          + " \001(\01328.google.cloud.dialogflow.cx.v3beta"
-          + "1.ContinuousTestResult\"Z\n\031RunContinuousT"
-          + "estMetadata\022=\n\006errors\030\001 \003(\0132-.google.clo"
-          + "ud.dialogflow.cx.v3beta1.TestError\"\221\001\n L"
-          + "istContinuousTestResultsRequest\022F\n\006paren"
-          + "t\030\001 \001(\tB6\340A\002\372A0\022.dialogflow.googleapis.c"
-          + "om/ContinuousTestResult\022\021\n\tpage_size\030\002 \001"
-          + "(\005\022\022\n\npage_token\030\003 \001(\t\"\227\001\n!ListContinuou"
-          + "sTestResultsResponse\022Y\n\027continuous_test_"
-          + "results\030\001 \003(\01328.google.cloud.dialogflow."
-          + "cx.v3beta1.ContinuousTestResult\022\027\n\017next_"
-          + "page_token\030\002 \001(\t\"\230\001\n\021DeployFlowRequest\022B"
-          + "\n\013environment\030\001 \001(\tB-\340A\002\372A\'\n%dialogflow."
-          + "googleapis.com/Environment\022?\n\014flow_versi"
-          + "on\030\002 \001(\tB)\340A\002\372A#\n!dialogflow.googleapis."
-          + "com/Version\"n\n\022DeployFlowResponse\022D\n\013env"
-          + "ironment\030\001 \001(\0132/.google.cloud.dialogflow"
-          + ".cx.v3beta1.Environment\022\022\n\ndeployment\030\002 "
-          + "\001(\t\"X\n\022DeployFlowMetadata\022B\n\013test_errors"
-          + "\030\001 \003(\0132-.google.cloud.dialogflow.cx.v3be"
-          + "ta1.TestError2\262\022\n\014Environments\022\336\001\n\020ListE"
-          + "nvironments\022;.google.cloud.dialogflow.cx"
-          + ".v3beta1.ListEnvironmentsRequest\032<.googl"
-          + "e.cloud.dialogflow.cx.v3beta1.ListEnviro"
-          + "nmentsResponse\"O\202\323\344\223\002@\022>/v3beta1/{parent"
-          + "=projects/*/locations/*/agents/*}/enviro"
-          + "nments\332A\006parent\022\313\001\n\016GetEnvironment\0229.goo"
-          + "gle.cloud.dialogflow.cx.v3beta1.GetEnvir"
-          + "onmentRequest\032/.google.cloud.dialogflow."
-          + "cx.v3beta1.Environment\"M\202\323\344\223\002@\022>/v3beta1"
-          + "/{name=projects/*/locations/*/agents/*/e"
-          + "nvironments/*}\332A\004name\022\203\002\n\021CreateEnvironm"
-          + "ent\022<.google.cloud.dialogflow.cx.v3beta1"
-          + ".CreateEnvironmentRequest\032\035.google.longr"
-          + "unning.Operation\"\220\001\202\323\344\223\002M\">/v3beta1/{par"
-          + "ent=projects/*/locations/*/agents/*}/env"
-          + "ironments:\013environment\332A\022parent,environm"
-          + "ent\312A%\n\013Environment\022\026google.protobuf.Str"
-          + "uct\022\224\002\n\021UpdateEnvironment\022<.google.cloud"
-          + ".dialogflow.cx.v3beta1.UpdateEnvironment"
-          + "Request\032\035.google.longrunning.Operation\"\241"
-          + "\001\202\323\344\223\002Y2J/v3beta1/{environment.name=proj"
-          + "ects/*/locations/*/agents/*/environments"
-          + "/*}:\013environment\332A\027environment,update_ma"
-          + "sk\312A%\n\013Environment\022\026google.protobuf.Stru"
-          + "ct\022\270\001\n\021DeleteEnvironment\022<.google.cloud."
-          + "dialogflow.cx.v3beta1.DeleteEnvironmentR"
-          + "equest\032\026.google.protobuf.Empty\"M\202\323\344\223\002@*>"
-          + "/v3beta1/{name=projects/*/locations/*/ag"
-          + "ents/*/environments/*}\332A\004name\022\215\002\n\030Lookup"
-          + "EnvironmentHistory\022C.google.cloud.dialog"
-          + "flow.cx.v3beta1.LookupEnvironmentHistory"
-          + "Request\032D.google.cloud.dialogflow.cx.v3b"
-          + "eta1.LookupEnvironmentHistoryResponse\"f\202"
-          + "\323\344\223\002Y\022W/v3beta1/{name=projects/*/locatio"
-          + "ns/*/agents/*/environments/*}:lookupEnvi"
-          + "ronmentHistory\332A\004name\022\216\002\n\021RunContinuousT"
-          + "est\022<.google.cloud.dialogflow.cx.v3beta1"
-          + ".RunContinuousTestRequest\032\035.google.longr"
-          + "unning.Operation\"\233\001\202\323\344\223\002\\\"W/v3beta1/{env"
-          + "ironment=projects/*/locations/*/agents/*"
-          + "/environments/*}:runContinuousTest:\001*\312A6"
-          + "\n\031RunContinuousTestResponse\022\031RunContinuo"
-          + "usTestMetadata\022\221\002\n\031ListContinuousTestRes"
-          + "ults\022D.google.cloud.dialogflow.cx.v3beta"
-          + "1.ListContinuousTestResultsRequest\032E.goo"
-          + "gle.cloud.dialogflow.cx.v3beta1.ListCont"
-          + "inuousTestResultsResponse\"g\202\323\344\223\002X\022V/v3be"
-          + "ta1/{parent=projects/*/locations/*/agent"
-          + "s/*/environments/*}/continuousTestResult"
-          + "s\332A\006parent\022\353\001\n\nDeployFlow\0225.google.cloud"
-          + ".dialogflow.cx.v3beta1.DeployFlowRequest"
-          + "\032\035.google.longrunning.Operation\"\206\001\202\323\344\223\002U"
-          + "\"P/v3beta1/{environment=projects/*/locat"
-          + "ions/*/agents/*/environments/*}:deployFl"
-          + "ow:\001*\312A(\n\022DeployFlowResponse\022\022DeployFlow"
-          + "Metadata\032x\312A\031dialogflow.googleapis.com\322A"
-          + "Yhttps://www.googleapis.com/auth/cloud-p"
-          + "latform,https://www.googleapis.com/auth/"
-          + "dialogflowB\330\001\n&com.google.cloud.dialogfl"
-          + "ow.cx.v3beta1B\020EnvironmentProtoP\001ZDgoogl"
-          + "e.golang.org/genproto/googleapis/cloud/d"
-          + "ialogflow/cx/v3beta1;cx\370\001\001\242\002\002DF\252\002\"Google"
-          + ".Cloud.Dialogflow.Cx.V3Beta1\352\002&Google::C"
-          + "loud::Dialogflow::CX::V3beta1b\006proto3"
+          + "1/test_case.proto\0320google/cloud/dialogfl"
+          + "ow/cx/v3beta1/webhook.proto\032#google/long"
+          + "running/operations.proto\032\033google/protobu"
+          + "f/empty.proto\032 google/protobuf/field_mas"
+          + "k.proto\032\037google/protobuf/timestamp.proto"
+          + "\"\230\005\n\013Environment\022\014\n\004name\030\001 \001(\t\022\031\n\014displa"
+          + "y_name\030\002 \001(\tB\003\340A\002\022\023\n\013description\030\003 \001(\t\022["
+          + "\n\017version_configs\030\006 \003(\0132=.google.cloud.d"
+          + "ialogflow.cx.v3beta1.Environment.Version"
+          + "ConfigB\003\340A\002\0224\n\013update_time\030\005 \001(\0132\032.googl"
+          + "e.protobuf.TimestampB\003\340A\003\022Z\n\021test_cases_"
+          + "config\030\007 \001(\0132?.google.cloud.dialogflow.c"
+          + "x.v3beta1.Environment.TestCasesConfig\032K\n"
+          + "\rVersionConfig\022:\n\007version\030\001 \001(\tB)\340A\002\372A#\n"
+          + "!dialogflow.googleapis.com/Version\032\217\001\n\017T"
+          + "estCasesConfig\022;\n\ntest_cases\030\001 \003(\tB\'\372A$\n"
+          + "\"dialogflow.googleapis.com/TestCase\022\035\n\025e"
+          + "nable_continuous_run\030\002 \001(\010\022 \n\030enable_pre"
+          + "deployment_run\030\003 \001(\010:}\352Az\n%dialogflow.go"
+          + "ogleapis.com/Environment\022Qprojects/{proj"
+          + "ect}/locations/{location}/agents/{agent}"
+          + "/environments/{environment}\"\177\n\027ListEnvir"
+          + "onmentsRequest\022=\n\006parent\030\001 \001(\tB-\340A\002\372A\'\022%"
+          + "dialogflow.googleapis.com/Environment\022\021\n"
+          + "\tpage_size\030\002 \001(\005\022\022\n\npage_token\030\003 \001(\t\"z\n\030"
+          + "ListEnvironmentsResponse\022E\n\014environments"
+          + "\030\001 \003(\0132/.google.cloud.dialogflow.cx.v3be"
+          + "ta1.Environment\022\027\n\017next_page_token\030\002 \001(\t"
+          + "\"T\n\025GetEnvironmentRequest\022;\n\004name\030\001 \001(\tB"
+          + "-\340A\002\372A\'\n%dialogflow.googleapis.com/Envir"
+          + "onment\"\244\001\n\030CreateEnvironmentRequest\022=\n\006p"
+          + "arent\030\001 \001(\tB-\340A\002\372A\'\022%dialogflow.googleap"
+          + "is.com/Environment\022I\n\013environment\030\002 \001(\0132"
+          + "/.google.cloud.dialogflow.cx.v3beta1.Env"
+          + "ironmentB\003\340A\002\"\233\001\n\030UpdateEnvironmentReque"
+          + "st\022I\n\013environment\030\001 \001(\0132/.google.cloud.d"
+          + "ialogflow.cx.v3beta1.EnvironmentB\003\340A\002\0224\n"
+          + "\013update_mask\030\002 \001(\0132\032.google.protobuf.Fie"
+          + "ldMaskB\003\340A\002\"W\n\030DeleteEnvironmentRequest\022"
+          + ";\n\004name\030\001 \001(\tB-\340A\002\372A\'\n%dialogflow.google"
+          + "apis.com/Environment\"\205\001\n\037LookupEnvironme"
+          + "ntHistoryRequest\022;\n\004name\030\001 \001(\tB-\340A\002\372A\'\n%"
+          + "dialogflow.googleapis.com/Environment\022\021\n"
+          + "\tpage_size\030\002 \001(\005\022\022\n\npage_token\030\003 \001(\t\"\202\001\n"
+          + " LookupEnvironmentHistoryResponse\022E\n\014env"
+          + "ironments\030\001 \003(\0132/.google.cloud.dialogflo"
+          + "w.cx.v3beta1.Environment\022\027\n\017next_page_to"
+          + "ken\030\002 \001(\t\"\215\004\n\024ContinuousTestResult\022\014\n\004na"
+          + "me\030\001 \001(\t\022]\n\006result\030\002 \001(\0162M.google.cloud."
+          + "dialogflow.cx.v3beta1.ContinuousTestResu"
+          + "lt.AggregatedTestResult\022H\n\021test_case_res"
+          + "ults\030\003 \003(\tB-\372A*\n(dialogflow.googleapis.c"
+          + "om/TestCaseResult\022,\n\010run_time\030\004 \001(\0132\032.go"
+          + "ogle.protobuf.Timestamp\"V\n\024AggregatedTes"
+          + "tResult\022&\n\"AGGREGATED_TEST_RESULT_UNSPEC"
+          + "IFIED\020\000\022\n\n\006PASSED\020\001\022\n\n\006FAILED\020\002:\267\001\352A\263\001\n."
+          + "dialogflow.googleapis.com/ContinuousTest"
+          + "Result\022\200\001projects/{project}/locations/{l"
+          + "ocation}/agents/{agent}/environments/{en"
+          + "vironment}/continuousTestResults/{contin"
+          + "uous_test_result}\"^\n\030RunContinuousTestRe"
+          + "quest\022B\n\013environment\030\001 \001(\tB-\340A\002\372A\'\n%dial"
+          + "ogflow.googleapis.com/Environment\"u\n\031Run"
+          + "ContinuousTestResponse\022X\n\026continuous_tes"
+          + "t_result\030\001 \001(\01328.google.cloud.dialogflow"
+          + ".cx.v3beta1.ContinuousTestResult\"Z\n\031RunC"
+          + "ontinuousTestMetadata\022=\n\006errors\030\001 \003(\0132-."
+          + "google.cloud.dialogflow.cx.v3beta1.TestE"
+          + "rror\"\221\001\n ListContinuousTestResultsReques"
+          + "t\022F\n\006parent\030\001 \001(\tB6\340A\002\372A0\022.dialogflow.go"
+          + "ogleapis.com/ContinuousTestResult\022\021\n\tpag"
+          + "e_size\030\002 \001(\005\022\022\n\npage_token\030\003 \001(\t\"\227\001\n!Lis"
+          + "tContinuousTestResultsResponse\022Y\n\027contin"
+          + "uous_test_results\030\001 \003(\01328.google.cloud.d"
+          + "ialogflow.cx.v3beta1.ContinuousTestResul"
+          + "t\022\027\n\017next_page_token\030\002 \001(\t\"\230\001\n\021DeployFlo"
+          + "wRequest\022B\n\013environment\030\001 \001(\tB-\340A\002\372A\'\n%d"
+          + "ialogflow.googleapis.com/Environment\022?\n\014"
+          + "flow_version\030\002 \001(\tB)\340A\002\372A#\n!dialogflow.g"
+          + "oogleapis.com/Version\"n\n\022DeployFlowRespo"
+          + "nse\022D\n\013environment\030\001 \001(\0132/.google.cloud."
+          + "dialogflow.cx.v3beta1.Environment\022\022\n\ndep"
+          + "loyment\030\002 \001(\t\"X\n\022DeployFlowMetadata\022B\n\013t"
+          + "est_errors\030\001 \003(\0132-.google.cloud.dialogfl"
+          + "ow.cx.v3beta1.TestError2\262\022\n\014Environments"
+          + "\022\336\001\n\020ListEnvironments\022;.google.cloud.dia"
+          + "logflow.cx.v3beta1.ListEnvironmentsReque"
+          + "st\032<.google.cloud.dialogflow.cx.v3beta1."
+          + "ListEnvironmentsResponse\"O\202\323\344\223\002@\022>/v3bet"
+          + "a1/{parent=projects/*/locations/*/agents"
+          + "/*}/environments\332A\006parent\022\313\001\n\016GetEnviron"
+          + "ment\0229.google.cloud.dialogflow.cx.v3beta"
+          + "1.GetEnvironmentRequest\032/.google.cloud.d"
+          + "ialogflow.cx.v3beta1.Environment\"M\202\323\344\223\002@"
+          + "\022>/v3beta1/{name=projects/*/locations/*/"
+          + "agents/*/environments/*}\332A\004name\022\203\002\n\021Crea"
+          + "teEnvironment\022<.google.cloud.dialogflow."
+          + "cx.v3beta1.CreateEnvironmentRequest\032\035.go"
+          + "ogle.longrunning.Operation\"\220\001\202\323\344\223\002M\">/v3"
+          + "beta1/{parent=projects/*/locations/*/age"
+          + "nts/*}/environments:\013environment\332A\022paren"
+          + "t,environment\312A%\n\013Environment\022\026google.pr"
+          + "otobuf.Struct\022\224\002\n\021UpdateEnvironment\022<.go"
+          + "ogle.cloud.dialogflow.cx.v3beta1.UpdateE"
+          + "nvironmentRequest\032\035.google.longrunning.O"
+          + "peration\"\241\001\202\323\344\223\002Y2J/v3beta1/{environment"
+          + ".name=projects/*/locations/*/agents/*/en"
+          + "vironments/*}:\013environment\332A\027environment"
+          + ",update_mask\312A%\n\013Environment\022\026google.pro"
+          + "tobuf.Struct\022\270\001\n\021DeleteEnvironment\022<.goo"
+          + "gle.cloud.dialogflow.cx.v3beta1.DeleteEn"
+          + "vironmentRequest\032\026.google.protobuf.Empty"
+          + "\"M\202\323\344\223\002@*>/v3beta1/{name=projects/*/loca"
+          + "tions/*/agents/*/environments/*}\332A\004name\022"
+          + "\215\002\n\030LookupEnvironmentHistory\022C.google.cl"
+          + "oud.dialogflow.cx.v3beta1.LookupEnvironm"
+          + "entHistoryRequest\032D.google.cloud.dialogf"
+          + "low.cx.v3beta1.LookupEnvironmentHistoryR"
+          + "esponse\"f\202\323\344\223\002Y\022W/v3beta1/{name=projects"
+          + "/*/locations/*/agents/*/environments/*}:"
+          + "lookupEnvironmentHistory\332A\004name\022\216\002\n\021RunC"
+          + "ontinuousTest\022<.google.cloud.dialogflow."
+          + "cx.v3beta1.RunContinuousTestRequest\032\035.go"
+          + "ogle.longrunning.Operation\"\233\001\202\323\344\223\002\\\"W/v3"
+          + "beta1/{environment=projects/*/locations/"
+          + "*/agents/*/environments/*}:runContinuous"
+          + "Test:\001*\312A6\n\031RunContinuousTestResponse\022\031R"
+          + "unContinuousTestMetadata\022\221\002\n\031ListContinu"
+          + "ousTestResults\022D.google.cloud.dialogflow"
+          + ".cx.v3beta1.ListContinuousTestResultsReq"
+          + "uest\032E.google.cloud.dialogflow.cx.v3beta"
+          + "1.ListContinuousTestResultsResponse\"g\202\323\344"
+          + "\223\002X\022V/v3beta1/{parent=projects/*/locatio"
+          + "ns/*/agents/*/environments/*}/continuous"
+          + "TestResults\332A\006parent\022\353\001\n\nDeployFlow\0225.go"
+          + "ogle.cloud.dialogflow.cx.v3beta1.DeployF"
+          + "lowRequest\032\035.google.longrunning.Operatio"
+          + "n\"\206\001\202\323\344\223\002U\"P/v3beta1/{environment=projec"
+          + "ts/*/locations/*/agents/*/environments/*"
+          + "}:deployFlow:\001*\312A(\n\022DeployFlowResponse\022\022"
+          + "DeployFlowMetadata\032x\312A\031dialogflow.google"
+          + "apis.com\322AYhttps://www.googleapis.com/au"
+          + "th/cloud-platform,https://www.googleapis"
+          + ".com/auth/dialogflowB\330\001\n&com.google.clou"
+          + "d.dialogflow.cx.v3beta1B\020EnvironmentProt"
+          + "oP\001ZDgoogle.golang.org/genproto/googleap"
+          + "is/cloud/dialogflow/cx/v3beta1;cx\370\001\001\242\002\002D"
+          + "F\252\002\"Google.Cloud.Dialogflow.Cx.V3Beta1\352\002"
+          + "&Google::Cloud::Dialogflow::CX::V3beta1b"
+          + "\006proto3"
     };
     descriptor =
         com.google.protobuf.Descriptors.FileDescriptor.internalBuildGeneratedFileFrom(
@@ -280,6 +282,7 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
               com.google.api.FieldBehaviorProto.getDescriptor(),
               com.google.api.ResourceProto.getDescriptor(),
               com.google.cloud.dialogflow.cx.v3beta1.TestCaseProto.getDescriptor(),
+              com.google.cloud.dialogflow.cx.v3beta1.WebhookProto.getDescriptor(),
               com.google.longrunning.OperationsProto.getDescriptor(),
               com.google.protobuf.EmptyProto.getDescriptor(),
               com.google.protobuf.FieldMaskProto.getDescriptor(),
@@ -471,6 +474,7 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
     com.google.api.FieldBehaviorProto.getDescriptor();
     com.google.api.ResourceProto.getDescriptor();
     com.google.cloud.dialogflow.cx.v3beta1.TestCaseProto.getDescriptor();
+    com.google.cloud.dialogflow.cx.v3beta1.WebhookProto.getDescriptor();
     com.google.longrunning.OperationsProto.getDescriptor();
     com.google.protobuf.EmptyProto.getDescriptor();
     com.google.protobuf.FieldMaskProto.getDescriptor();
diff --git a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessage.java b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessage.java
index a1b88940c..874e75422 100644
--- a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessage.java
+++ b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessage.java
@@ -253,6 +253,30 @@ private ResponseMessage(
               messageCase_ = 13;
               break;
             }
+          case 146:
+            {
+              com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall.Builder
+                  subBuilder = null;
+              if (messageCase_ == 18) {
+                subBuilder =
+                    ((com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+                            message_)
+                        .toBuilder();
+              }
+              message_ =
+                  input.readMessage(
+                      com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+                          .parser(),
+                      extensionRegistry);
+              if (subBuilder != null) {
+                subBuilder.mergeFrom(
+                    (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+                        message_);
+                message_ = subBuilder.buildPartial();
+              }
+              messageCase_ = 18;
+              break;
+            }
           default:
             {
               if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
@@ -7523,188 +7547,1031 @@ public com.google.protobuf.Parser<MixedAudio> getParserForType() {
     }
   }
 
-  private int messageCase_ = 0;
-  private java.lang.Object message_;
-
-  public enum MessageCase
-      implements
-          com.google.protobuf.Internal.EnumLite,
-          com.google.protobuf.AbstractMessage.InternalOneOfEnum {
-    TEXT(1),
-    PAYLOAD(2),
-    CONVERSATION_SUCCESS(9),
-    OUTPUT_AUDIO_TEXT(8),
-    LIVE_AGENT_HANDOFF(10),
-    END_INTERACTION(11),
-    PLAY_AUDIO(12),
-    MIXED_AUDIO(13),
-    MESSAGE_NOT_SET(0);
-    private final int value;
+  public interface TelephonyTransferCallOrBuilder
+      extends
+      // @@protoc_insertion_point(interface_extends:google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+      com.google.protobuf.MessageOrBuilder {
 
-    private MessageCase(int value) {
-      this.value = value;
-    }
     /**
-     * @param value The number of the enum to look for.
-     * @return The enum associated with the given number.
-     * @deprecated Use {@link #forNumber(int)} instead.
+     *
+     *
+     * <pre>
+     * Transfer the call to a phone number
+     * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+     * </pre>
+     *
+     * <code>string phone_number = 1;</code>
+     *
+     * @return Whether the phoneNumber field is set.
      */
-    @java.lang.Deprecated
-    public static MessageCase valueOf(int value) {
-      return forNumber(value);
-    }
-
-    public static MessageCase forNumber(int value) {
-      switch (value) {
-        case 1:
-          return TEXT;
-        case 2:
-          return PAYLOAD;
-        case 9:
-          return CONVERSATION_SUCCESS;
-        case 8:
-          return OUTPUT_AUDIO_TEXT;
-        case 10:
-          return LIVE_AGENT_HANDOFF;
-        case 11:
-          return END_INTERACTION;
-        case 12:
-          return PLAY_AUDIO;
-        case 13:
-          return MIXED_AUDIO;
-        case 0:
-          return MESSAGE_NOT_SET;
-        default:
-          return null;
-      }
-    }
-
-    public int getNumber() {
-      return this.value;
-    }
-  };
-
-  public MessageCase getMessageCase() {
-    return MessageCase.forNumber(messageCase_);
-  }
+    boolean hasPhoneNumber();
+    /**
+     *
+     *
+     * <pre>
+     * Transfer the call to a phone number
+     * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+     * </pre>
+     *
+     * <code>string phone_number = 1;</code>
+     *
+     * @return The phoneNumber.
+     */
+    java.lang.String getPhoneNumber();
+    /**
+     *
+     *
+     * <pre>
+     * Transfer the call to a phone number
+     * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+     * </pre>
+     *
+     * <code>string phone_number = 1;</code>
+     *
+     * @return The bytes for phoneNumber.
+     */
+    com.google.protobuf.ByteString getPhoneNumberBytes();
 
-  public static final int TEXT_FIELD_NUMBER = 1;
-  /**
-   *
-   *
-   * <pre>
-   * Returns a text response.
-   * </pre>
-   *
-   * <code>.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text text = 1;</code>
-   *
-   * @return Whether the text field is set.
-   */
-  @java.lang.Override
-  public boolean hasText() {
-    return messageCase_ == 1;
+    public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall.EndpointCase
+        getEndpointCase();
   }
   /**
    *
    *
    * <pre>
-   * Returns a text response.
+   * Represents the signal that telles the client to transfer the phone call
+   * connected to the agent to a third-party endpoint.
    * </pre>
    *
-   * <code>.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text text = 1;</code>
-   *
-   * @return The text.
+   * Protobuf type {@code google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall}
    */
-  @java.lang.Override
-  public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text getText() {
-    if (messageCase_ == 1) {
-      return (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text) message_;
+  public static final class TelephonyTransferCall extends com.google.protobuf.GeneratedMessageV3
+      implements
+      // @@protoc_insertion_point(message_implements:google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+      TelephonyTransferCallOrBuilder {
+    private static final long serialVersionUID = 0L;
+    // Use TelephonyTransferCall.newBuilder() to construct.
+    private TelephonyTransferCall(com.google.protobuf.GeneratedMessageV3.Builder<?> builder) {
+      super(builder);
     }
-    return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text.getDefaultInstance();
-  }
-  /**
-   *
-   *
-   * <pre>
-   * Returns a text response.
-   * </pre>
-   *
-   * <code>.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text text = 1;</code>
-   */
-  @java.lang.Override
-  public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TextOrBuilder getTextOrBuilder() {
-    if (messageCase_ == 1) {
-      return (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text) message_;
+
+    private TelephonyTransferCall() {}
+
+    @java.lang.Override
+    @SuppressWarnings({"unused"})
+    protected java.lang.Object newInstance(UnusedPrivateParameter unused) {
+      return new TelephonyTransferCall();
     }
-    return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text.getDefaultInstance();
-  }
 
-  public static final int PAYLOAD_FIELD_NUMBER = 2;
-  /**
-   *
-   *
-   * <pre>
-   * Returns a response containing a custom, platform-specific payload.
-   * </pre>
-   *
-   * <code>.google.protobuf.Struct payload = 2;</code>
-   *
-   * @return Whether the payload field is set.
-   */
-  @java.lang.Override
-  public boolean hasPayload() {
-    return messageCase_ == 2;
-  }
-  /**
-   *
-   *
-   * <pre>
-   * Returns a response containing a custom, platform-specific payload.
-   * </pre>
-   *
-   * <code>.google.protobuf.Struct payload = 2;</code>
-   *
-   * @return The payload.
-   */
-  @java.lang.Override
-  public com.google.protobuf.Struct getPayload() {
-    if (messageCase_ == 2) {
-      return (com.google.protobuf.Struct) message_;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
+      return this.unknownFields;
     }
-    return com.google.protobuf.Struct.getDefaultInstance();
-  }
-  /**
-   *
-   *
-   * <pre>
-   * Returns a response containing a custom, platform-specific payload.
-   * </pre>
-   *
-   * <code>.google.protobuf.Struct payload = 2;</code>
-   */
-  @java.lang.Override
-  public com.google.protobuf.StructOrBuilder getPayloadOrBuilder() {
-    if (messageCase_ == 2) {
-      return (com.google.protobuf.Struct) message_;
+
+    private TelephonyTransferCall(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      this();
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                java.lang.String s = input.readStringRequireUtf8();
+                endpointCase_ = 1;
+                endpoint_ = s;
+                break;
+              }
+            default:
+              {
+                if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
+                  done = true;
+                }
+                break;
+              }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
+      } finally {
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
     }
-    return com.google.protobuf.Struct.getDefaultInstance();
-  }
 
-  public static final int CONVERSATION_SUCCESS_FIELD_NUMBER = 9;
-  /**
-   *
-   *
-   * <pre>
-   * Indicates that the conversation succeeded.
-   * </pre>
-   *
-   * <code>
-   * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.ConversationSuccess conversation_success = 9;
-   * </code>
-   *
-   * @return Whether the conversationSuccess field is set.
-   */
-  @java.lang.Override
+    public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
+      return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessageProto
+          .internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_TelephonyTransferCall_descriptor;
+    }
+
+    @java.lang.Override
+    protected com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessageProto
+          .internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_TelephonyTransferCall_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall.class,
+              com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall.Builder
+                  .class);
+    }
+
+    private int endpointCase_ = 0;
+    private java.lang.Object endpoint_;
+
+    public enum EndpointCase
+        implements
+            com.google.protobuf.Internal.EnumLite,
+            com.google.protobuf.AbstractMessage.InternalOneOfEnum {
+      PHONE_NUMBER(1),
+      ENDPOINT_NOT_SET(0);
+      private final int value;
+
+      private EndpointCase(int value) {
+        this.value = value;
+      }
+      /**
+       * @param value The number of the enum to look for.
+       * @return The enum associated with the given number.
+       * @deprecated Use {@link #forNumber(int)} instead.
+       */
+      @java.lang.Deprecated
+      public static EndpointCase valueOf(int value) {
+        return forNumber(value);
+      }
+
+      public static EndpointCase forNumber(int value) {
+        switch (value) {
+          case 1:
+            return PHONE_NUMBER;
+          case 0:
+            return ENDPOINT_NOT_SET;
+          default:
+            return null;
+        }
+      }
+
+      public int getNumber() {
+        return this.value;
+      }
+    };
+
+    public EndpointCase getEndpointCase() {
+      return EndpointCase.forNumber(endpointCase_);
+    }
+
+    public static final int PHONE_NUMBER_FIELD_NUMBER = 1;
+    /**
+     *
+     *
+     * <pre>
+     * Transfer the call to a phone number
+     * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+     * </pre>
+     *
+     * <code>string phone_number = 1;</code>
+     *
+     * @return Whether the phoneNumber field is set.
+     */
+    public boolean hasPhoneNumber() {
+      return endpointCase_ == 1;
+    }
+    /**
+     *
+     *
+     * <pre>
+     * Transfer the call to a phone number
+     * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+     * </pre>
+     *
+     * <code>string phone_number = 1;</code>
+     *
+     * @return The phoneNumber.
+     */
+    public java.lang.String getPhoneNumber() {
+      java.lang.Object ref = "";
+      if (endpointCase_ == 1) {
+        ref = endpoint_;
+      }
+      if (ref instanceof java.lang.String) {
+        return (java.lang.String) ref;
+      } else {
+        com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
+        java.lang.String s = bs.toStringUtf8();
+        if (endpointCase_ == 1) {
+          endpoint_ = s;
+        }
+        return s;
+      }
+    }
+    /**
+     *
+     *
+     * <pre>
+     * Transfer the call to a phone number
+     * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+     * </pre>
+     *
+     * <code>string phone_number = 1;</code>
+     *
+     * @return The bytes for phoneNumber.
+     */
+    public com.google.protobuf.ByteString getPhoneNumberBytes() {
+      java.lang.Object ref = "";
+      if (endpointCase_ == 1) {
+        ref = endpoint_;
+      }
+      if (ref instanceof java.lang.String) {
+        com.google.protobuf.ByteString b =
+            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
+        if (endpointCase_ == 1) {
+          endpoint_ = b;
+        }
+        return b;
+      } else {
+        return (com.google.protobuf.ByteString) ref;
+      }
+    }
+
+    private byte memoizedIsInitialized = -1;
+
+    @java.lang.Override
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized == 1) return true;
+      if (isInitialized == 0) return false;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    @java.lang.Override
+    public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
+      if (endpointCase_ == 1) {
+        com.google.protobuf.GeneratedMessageV3.writeString(output, 1, endpoint_);
+      }
+      unknownFields.writeTo(output);
+    }
+
+    @java.lang.Override
+    public int getSerializedSize() {
+      int size = memoizedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (endpointCase_ == 1) {
+        size += com.google.protobuf.GeneratedMessageV3.computeStringSize(1, endpoint_);
+      }
+      size += unknownFields.getSerializedSize();
+      memoizedSize = size;
+      return size;
+    }
+
+    @java.lang.Override
+    public boolean equals(final java.lang.Object obj) {
+      if (obj == this) {
+        return true;
+      }
+      if (!(obj
+          instanceof
+          com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)) {
+        return super.equals(obj);
+      }
+      com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall other =
+          (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall) obj;
+
+      if (!getEndpointCase().equals(other.getEndpointCase())) return false;
+      switch (endpointCase_) {
+        case 1:
+          if (!getPhoneNumber().equals(other.getPhoneNumber())) return false;
+          break;
+        case 0:
+        default:
+      }
+      if (!unknownFields.equals(other.unknownFields)) return false;
+      return true;
+    }
+
+    @java.lang.Override
+    public int hashCode() {
+      if (memoizedHashCode != 0) {
+        return memoizedHashCode;
+      }
+      int hash = 41;
+      hash = (19 * hash) + getDescriptor().hashCode();
+      switch (endpointCase_) {
+        case 1:
+          hash = (37 * hash) + PHONE_NUMBER_FIELD_NUMBER;
+          hash = (53 * hash) + getPhoneNumber().hashCode();
+          break;
+        case 0:
+        default:
+      }
+      hash = (29 * hash) + unknownFields.hashCode();
+      memoizedHashCode = hash;
+      return hash;
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseFrom(java.nio.ByteBuffer data)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseFrom(
+            java.nio.ByteBuffer data, com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseFrom(com.google.protobuf.ByteString data)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseFrom(
+            com.google.protobuf.ByteString data,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseFrom(byte[] data) throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseFrom(byte[] data, com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseFrom(java.io.InputStream input) throws java.io.IOException {
+      return com.google.protobuf.GeneratedMessageV3.parseWithIOException(PARSER, input);
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseFrom(
+            java.io.InputStream input, com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+      return com.google.protobuf.GeneratedMessageV3.parseWithIOException(
+          PARSER, input, extensionRegistry);
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseDelimitedFrom(java.io.InputStream input) throws java.io.IOException {
+      return com.google.protobuf.GeneratedMessageV3.parseDelimitedWithIOException(PARSER, input);
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseDelimitedFrom(
+            java.io.InputStream input, com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+      return com.google.protobuf.GeneratedMessageV3.parseDelimitedWithIOException(
+          PARSER, input, extensionRegistry);
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseFrom(com.google.protobuf.CodedInputStream input) throws java.io.IOException {
+      return com.google.protobuf.GeneratedMessageV3.parseWithIOException(PARSER, input);
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        parseFrom(
+            com.google.protobuf.CodedInputStream input,
+            com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+            throws java.io.IOException {
+      return com.google.protobuf.GeneratedMessageV3.parseWithIOException(
+          PARSER, input, extensionRegistry);
+    }
+
+    @java.lang.Override
+    public Builder newBuilderForType() {
+      return newBuilder();
+    }
+
+    public static Builder newBuilder() {
+      return DEFAULT_INSTANCE.toBuilder();
+    }
+
+    public static Builder newBuilder(
+        com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall prototype) {
+      return DEFAULT_INSTANCE.toBuilder().mergeFrom(prototype);
+    }
+
+    @java.lang.Override
+    public Builder toBuilder() {
+      return this == DEFAULT_INSTANCE ? new Builder() : new Builder().mergeFrom(this);
+    }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     *
+     *
+     * <pre>
+     * Represents the signal that telles the client to transfer the phone call
+     * connected to the agent to a third-party endpoint.
+     * </pre>
+     *
+     * Protobuf type {@code
+     * google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall}
+     */
+    public static final class Builder
+        extends com.google.protobuf.GeneratedMessageV3.Builder<Builder>
+        implements
+        // @@protoc_insertion_point(builder_implements:google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+        com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCallOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
+        return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessageProto
+            .internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_TelephonyTransferCall_descriptor;
+      }
+
+      @java.lang.Override
+      protected com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessageProto
+            .internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_TelephonyTransferCall_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall.class,
+                com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall.Builder
+                    .class);
+      }
+
+      // Construct using
+      // com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
+      }
+
+      @java.lang.Override
+      public Builder clear() {
+        super.clear();
+        endpointCase_ = 0;
+        endpoint_ = null;
+        return this;
+      }
+
+      @java.lang.Override
+      public com.google.protobuf.Descriptors.Descriptor getDescriptorForType() {
+        return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessageProto
+            .internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_TelephonyTransferCall_descriptor;
+      }
+
+      @java.lang.Override
+      public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+          getDefaultInstanceForType() {
+        return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+            .getDefaultInstance();
+      }
+
+      @java.lang.Override
+      public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall build() {
+        com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall result =
+            buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      @java.lang.Override
+      public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+          buildPartial() {
+        com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall result =
+            new com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall(this);
+        if (endpointCase_ == 1) {
+          result.endpoint_ = endpoint_;
+        }
+        result.endpointCase_ = endpointCase_;
+        onBuilt();
+        return result;
+      }
+
+      @java.lang.Override
+      public Builder clone() {
+        return super.clone();
+      }
+
+      @java.lang.Override
+      public Builder setField(
+          com.google.protobuf.Descriptors.FieldDescriptor field, java.lang.Object value) {
+        return super.setField(field, value);
+      }
+
+      @java.lang.Override
+      public Builder clearField(com.google.protobuf.Descriptors.FieldDescriptor field) {
+        return super.clearField(field);
+      }
+
+      @java.lang.Override
+      public Builder clearOneof(com.google.protobuf.Descriptors.OneofDescriptor oneof) {
+        return super.clearOneof(oneof);
+      }
+
+      @java.lang.Override
+      public Builder setRepeatedField(
+          com.google.protobuf.Descriptors.FieldDescriptor field,
+          int index,
+          java.lang.Object value) {
+        return super.setRepeatedField(field, index, value);
+      }
+
+      @java.lang.Override
+      public Builder addRepeatedField(
+          com.google.protobuf.Descriptors.FieldDescriptor field, java.lang.Object value) {
+        return super.addRepeatedField(field, value);
+      }
+
+      @java.lang.Override
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other
+            instanceof
+            com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall) {
+          return mergeFrom(
+              (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall) other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(
+          com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall other) {
+        if (other
+            == com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+                .getDefaultInstance()) return this;
+        switch (other.getEndpointCase()) {
+          case PHONE_NUMBER:
+            {
+              endpointCase_ = 1;
+              endpoint_ = other.endpoint_;
+              onChanged();
+              break;
+            }
+          case ENDPOINT_NOT_SET:
+            {
+              break;
+            }
+        }
+        this.mergeUnknownFields(other.unknownFields);
+        onChanged();
+        return this;
+      }
+
+      @java.lang.Override
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      @java.lang.Override
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall parsedMessage =
+            null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage =
+              (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+                  e.getUnfinishedMessage();
+          throw e.unwrapIOException();
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+
+      private int endpointCase_ = 0;
+      private java.lang.Object endpoint_;
+
+      public EndpointCase getEndpointCase() {
+        return EndpointCase.forNumber(endpointCase_);
+      }
+
+      public Builder clearEndpoint() {
+        endpointCase_ = 0;
+        endpoint_ = null;
+        onChanged();
+        return this;
+      }
+
+      /**
+       *
+       *
+       * <pre>
+       * Transfer the call to a phone number
+       * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+       * </pre>
+       *
+       * <code>string phone_number = 1;</code>
+       *
+       * @return Whether the phoneNumber field is set.
+       */
+      @java.lang.Override
+      public boolean hasPhoneNumber() {
+        return endpointCase_ == 1;
+      }
+      /**
+       *
+       *
+       * <pre>
+       * Transfer the call to a phone number
+       * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+       * </pre>
+       *
+       * <code>string phone_number = 1;</code>
+       *
+       * @return The phoneNumber.
+       */
+      @java.lang.Override
+      public java.lang.String getPhoneNumber() {
+        java.lang.Object ref = "";
+        if (endpointCase_ == 1) {
+          ref = endpoint_;
+        }
+        if (!(ref instanceof java.lang.String)) {
+          com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
+          java.lang.String s = bs.toStringUtf8();
+          if (endpointCase_ == 1) {
+            endpoint_ = s;
+          }
+          return s;
+        } else {
+          return (java.lang.String) ref;
+        }
+      }
+      /**
+       *
+       *
+       * <pre>
+       * Transfer the call to a phone number
+       * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+       * </pre>
+       *
+       * <code>string phone_number = 1;</code>
+       *
+       * @return The bytes for phoneNumber.
+       */
+      @java.lang.Override
+      public com.google.protobuf.ByteString getPhoneNumberBytes() {
+        java.lang.Object ref = "";
+        if (endpointCase_ == 1) {
+          ref = endpoint_;
+        }
+        if (ref instanceof String) {
+          com.google.protobuf.ByteString b =
+              com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
+          if (endpointCase_ == 1) {
+            endpoint_ = b;
+          }
+          return b;
+        } else {
+          return (com.google.protobuf.ByteString) ref;
+        }
+      }
+      /**
+       *
+       *
+       * <pre>
+       * Transfer the call to a phone number
+       * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+       * </pre>
+       *
+       * <code>string phone_number = 1;</code>
+       *
+       * @param value The phoneNumber to set.
+       * @return This builder for chaining.
+       */
+      public Builder setPhoneNumber(java.lang.String value) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        endpointCase_ = 1;
+        endpoint_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       *
+       *
+       * <pre>
+       * Transfer the call to a phone number
+       * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+       * </pre>
+       *
+       * <code>string phone_number = 1;</code>
+       *
+       * @return This builder for chaining.
+       */
+      public Builder clearPhoneNumber() {
+        if (endpointCase_ == 1) {
+          endpointCase_ = 0;
+          endpoint_ = null;
+          onChanged();
+        }
+        return this;
+      }
+      /**
+       *
+       *
+       * <pre>
+       * Transfer the call to a phone number
+       * in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+       * </pre>
+       *
+       * <code>string phone_number = 1;</code>
+       *
+       * @param value The bytes for phoneNumber to set.
+       * @return This builder for chaining.
+       */
+      public Builder setPhoneNumberBytes(com.google.protobuf.ByteString value) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        checkByteStringIsUtf8(value);
+        endpointCase_ = 1;
+        endpoint_ = value;
+        onChanged();
+        return this;
+      }
+
+      @java.lang.Override
+      public final Builder setUnknownFields(
+          final com.google.protobuf.UnknownFieldSet unknownFields) {
+        return super.setUnknownFields(unknownFields);
+      }
+
+      @java.lang.Override
+      public final Builder mergeUnknownFields(
+          final com.google.protobuf.UnknownFieldSet unknownFields) {
+        return super.mergeUnknownFields(unknownFields);
+      }
+
+      // @@protoc_insertion_point(builder_scope:google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+    }
+
+    // @@protoc_insertion_point(class_scope:google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+    private static final com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage
+            .TelephonyTransferCall
+        DEFAULT_INSTANCE;
+
+    static {
+      DEFAULT_INSTANCE =
+          new com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall();
+    }
+
+    public static com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        getDefaultInstance() {
+      return DEFAULT_INSTANCE;
+    }
+
+    private static final com.google.protobuf.Parser<TelephonyTransferCall> PARSER =
+        new com.google.protobuf.AbstractParser<TelephonyTransferCall>() {
+          @java.lang.Override
+          public TelephonyTransferCall parsePartialFrom(
+              com.google.protobuf.CodedInputStream input,
+              com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+              throws com.google.protobuf.InvalidProtocolBufferException {
+            return new TelephonyTransferCall(input, extensionRegistry);
+          }
+        };
+
+    public static com.google.protobuf.Parser<TelephonyTransferCall> parser() {
+      return PARSER;
+    }
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<TelephonyTransferCall> getParserForType() {
+      return PARSER;
+    }
+
+    @java.lang.Override
+    public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        getDefaultInstanceForType() {
+      return DEFAULT_INSTANCE;
+    }
+  }
+
+  private int messageCase_ = 0;
+  private java.lang.Object message_;
+
+  public enum MessageCase
+      implements
+          com.google.protobuf.Internal.EnumLite,
+          com.google.protobuf.AbstractMessage.InternalOneOfEnum {
+    TEXT(1),
+    PAYLOAD(2),
+    CONVERSATION_SUCCESS(9),
+    OUTPUT_AUDIO_TEXT(8),
+    LIVE_AGENT_HANDOFF(10),
+    END_INTERACTION(11),
+    PLAY_AUDIO(12),
+    MIXED_AUDIO(13),
+    TELEPHONY_TRANSFER_CALL(18),
+    MESSAGE_NOT_SET(0);
+    private final int value;
+
+    private MessageCase(int value) {
+      this.value = value;
+    }
+    /**
+     * @param value The number of the enum to look for.
+     * @return The enum associated with the given number.
+     * @deprecated Use {@link #forNumber(int)} instead.
+     */
+    @java.lang.Deprecated
+    public static MessageCase valueOf(int value) {
+      return forNumber(value);
+    }
+
+    public static MessageCase forNumber(int value) {
+      switch (value) {
+        case 1:
+          return TEXT;
+        case 2:
+          return PAYLOAD;
+        case 9:
+          return CONVERSATION_SUCCESS;
+        case 8:
+          return OUTPUT_AUDIO_TEXT;
+        case 10:
+          return LIVE_AGENT_HANDOFF;
+        case 11:
+          return END_INTERACTION;
+        case 12:
+          return PLAY_AUDIO;
+        case 13:
+          return MIXED_AUDIO;
+        case 18:
+          return TELEPHONY_TRANSFER_CALL;
+        case 0:
+          return MESSAGE_NOT_SET;
+        default:
+          return null;
+      }
+    }
+
+    public int getNumber() {
+      return this.value;
+    }
+  };
+
+  public MessageCase getMessageCase() {
+    return MessageCase.forNumber(messageCase_);
+  }
+
+  public static final int TEXT_FIELD_NUMBER = 1;
+  /**
+   *
+   *
+   * <pre>
+   * Returns a text response.
+   * </pre>
+   *
+   * <code>.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text text = 1;</code>
+   *
+   * @return Whether the text field is set.
+   */
+  @java.lang.Override
+  public boolean hasText() {
+    return messageCase_ == 1;
+  }
+  /**
+   *
+   *
+   * <pre>
+   * Returns a text response.
+   * </pre>
+   *
+   * <code>.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text text = 1;</code>
+   *
+   * @return The text.
+   */
+  @java.lang.Override
+  public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text getText() {
+    if (messageCase_ == 1) {
+      return (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text) message_;
+    }
+    return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text.getDefaultInstance();
+  }
+  /**
+   *
+   *
+   * <pre>
+   * Returns a text response.
+   * </pre>
+   *
+   * <code>.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text text = 1;</code>
+   */
+  @java.lang.Override
+  public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TextOrBuilder getTextOrBuilder() {
+    if (messageCase_ == 1) {
+      return (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text) message_;
+    }
+    return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.Text.getDefaultInstance();
+  }
+
+  public static final int PAYLOAD_FIELD_NUMBER = 2;
+  /**
+   *
+   *
+   * <pre>
+   * Returns a response containing a custom, platform-specific payload.
+   * </pre>
+   *
+   * <code>.google.protobuf.Struct payload = 2;</code>
+   *
+   * @return Whether the payload field is set.
+   */
+  @java.lang.Override
+  public boolean hasPayload() {
+    return messageCase_ == 2;
+  }
+  /**
+   *
+   *
+   * <pre>
+   * Returns a response containing a custom, platform-specific payload.
+   * </pre>
+   *
+   * <code>.google.protobuf.Struct payload = 2;</code>
+   *
+   * @return The payload.
+   */
+  @java.lang.Override
+  public com.google.protobuf.Struct getPayload() {
+    if (messageCase_ == 2) {
+      return (com.google.protobuf.Struct) message_;
+    }
+    return com.google.protobuf.Struct.getDefaultInstance();
+  }
+  /**
+   *
+   *
+   * <pre>
+   * Returns a response containing a custom, platform-specific payload.
+   * </pre>
+   *
+   * <code>.google.protobuf.Struct payload = 2;</code>
+   */
+  @java.lang.Override
+  public com.google.protobuf.StructOrBuilder getPayloadOrBuilder() {
+    if (messageCase_ == 2) {
+      return (com.google.protobuf.Struct) message_;
+    }
+    return com.google.protobuf.Struct.getDefaultInstance();
+  }
+
+  public static final int CONVERSATION_SUCCESS_FIELD_NUMBER = 9;
+  /**
+   *
+   *
+   * <pre>
+   * Indicates that the conversation succeeded.
+   * </pre>
+   *
+   * <code>
+   * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.ConversationSuccess conversation_success = 9;
+   * </code>
+   *
+   * @return Whether the conversationSuccess field is set.
+   */
+  @java.lang.Override
   public boolean hasConversationSuccess() {
     return messageCase_ == 9;
   }
@@ -8079,6 +8946,72 @@ public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.MixedAudio getMixe
     return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.MixedAudio.getDefaultInstance();
   }
 
+  public static final int TELEPHONY_TRANSFER_CALL_FIELD_NUMBER = 18;
+  /**
+   *
+   *
+   * <pre>
+   * A signal that the client should transfer the phone call connected to
+   * this agent to a third-party endpoint.
+   * </pre>
+   *
+   * <code>
+   * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+   * </code>
+   *
+   * @return Whether the telephonyTransferCall field is set.
+   */
+  @java.lang.Override
+  public boolean hasTelephonyTransferCall() {
+    return messageCase_ == 18;
+  }
+  /**
+   *
+   *
+   * <pre>
+   * A signal that the client should transfer the phone call connected to
+   * this agent to a third-party endpoint.
+   * </pre>
+   *
+   * <code>
+   * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+   * </code>
+   *
+   * @return The telephonyTransferCall.
+   */
+  @java.lang.Override
+  public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+      getTelephonyTransferCall() {
+    if (messageCase_ == 18) {
+      return (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+          message_;
+    }
+    return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        .getDefaultInstance();
+  }
+  /**
+   *
+   *
+   * <pre>
+   * A signal that the client should transfer the phone call connected to
+   * this agent to a third-party endpoint.
+   * </pre>
+   *
+   * <code>
+   * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+   * </code>
+   */
+  @java.lang.Override
+  public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCallOrBuilder
+      getTelephonyTransferCallOrBuilder() {
+    if (messageCase_ == 18) {
+      return (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+          message_;
+    }
+    return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        .getDefaultInstance();
+  }
+
   private byte memoizedIsInitialized = -1;
 
   @java.lang.Override
@@ -8124,6 +9057,11 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
       output.writeMessage(
           13, (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.MixedAudio) message_);
     }
+    if (messageCase_ == 18) {
+      output.writeMessage(
+          18,
+          (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall) message_);
+    }
     unknownFields.writeTo(output);
   }
 
@@ -8176,6 +9114,13 @@ public int getSerializedSize() {
           com.google.protobuf.CodedOutputStream.computeMessageSize(
               13, (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.MixedAudio) message_);
     }
+    if (messageCase_ == 18) {
+      size +=
+          com.google.protobuf.CodedOutputStream.computeMessageSize(
+              18,
+              (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+                  message_);
+    }
     size += unknownFields.getSerializedSize();
     memoizedSize = size;
     return size;
@@ -8218,6 +9163,9 @@ public boolean equals(final java.lang.Object obj) {
       case 13:
         if (!getMixedAudio().equals(other.getMixedAudio())) return false;
         break;
+      case 18:
+        if (!getTelephonyTransferCall().equals(other.getTelephonyTransferCall())) return false;
+        break;
       case 0:
       default:
     }
@@ -8265,6 +9213,10 @@ public int hashCode() {
         hash = (37 * hash) + MIXED_AUDIO_FIELD_NUMBER;
         hash = (53 * hash) + getMixedAudio().hashCode();
         break;
+      case 18:
+        hash = (37 * hash) + TELEPHONY_TRANSFER_CALL_FIELD_NUMBER;
+        hash = (53 * hash) + getTelephonyTransferCall().hashCode();
+        break;
       case 0:
       default:
     }
@@ -8512,6 +9464,13 @@ public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage buildPartial() {
           result.message_ = mixedAudioBuilder_.build();
         }
       }
+      if (messageCase_ == 18) {
+        if (telephonyTransferCallBuilder_ == null) {
+          result.message_ = message_;
+        } else {
+          result.message_ = telephonyTransferCallBuilder_.build();
+        }
+      }
       result.messageCase_ = messageCase_;
       onBuilt();
       return result;
@@ -8604,6 +9563,11 @@ public Builder mergeFrom(com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage
             mergeMixedAudio(other.getMixedAudio());
             break;
           }
+        case TELEPHONY_TRANSFER_CALL:
+          {
+            mergeTelephonyTransferCall(other.getTelephonyTransferCall());
+            break;
+          }
         case MESSAGE_NOT_SET:
           {
             break;
@@ -10602,6 +11566,262 @@ public Builder clearMixedAudio() {
       return mixedAudioBuilder_;
     }
 
+    private com.google.protobuf.SingleFieldBuilderV3<
+            com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall,
+            com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall.Builder,
+            com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCallOrBuilder>
+        telephonyTransferCallBuilder_;
+    /**
+     *
+     *
+     * <pre>
+     * A signal that the client should transfer the phone call connected to
+     * this agent to a third-party endpoint.
+     * </pre>
+     *
+     * <code>
+     * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+     * </code>
+     *
+     * @return Whether the telephonyTransferCall field is set.
+     */
+    @java.lang.Override
+    public boolean hasTelephonyTransferCall() {
+      return messageCase_ == 18;
+    }
+    /**
+     *
+     *
+     * <pre>
+     * A signal that the client should transfer the phone call connected to
+     * this agent to a third-party endpoint.
+     * </pre>
+     *
+     * <code>
+     * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+     * </code>
+     *
+     * @return The telephonyTransferCall.
+     */
+    @java.lang.Override
+    public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+        getTelephonyTransferCall() {
+      if (telephonyTransferCallBuilder_ == null) {
+        if (messageCase_ == 18) {
+          return (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+              message_;
+        }
+        return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+            .getDefaultInstance();
+      } else {
+        if (messageCase_ == 18) {
+          return telephonyTransferCallBuilder_.getMessage();
+        }
+        return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+            .getDefaultInstance();
+      }
+    }
+    /**
+     *
+     *
+     * <pre>
+     * A signal that the client should transfer the phone call connected to
+     * this agent to a third-party endpoint.
+     * </pre>
+     *
+     * <code>
+     * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+     * </code>
+     */
+    public Builder setTelephonyTransferCall(
+        com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall value) {
+      if (telephonyTransferCallBuilder_ == null) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        message_ = value;
+        onChanged();
+      } else {
+        telephonyTransferCallBuilder_.setMessage(value);
+      }
+      messageCase_ = 18;
+      return this;
+    }
+    /**
+     *
+     *
+     * <pre>
+     * A signal that the client should transfer the phone call connected to
+     * this agent to a third-party endpoint.
+     * </pre>
+     *
+     * <code>
+     * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+     * </code>
+     */
+    public Builder setTelephonyTransferCall(
+        com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall.Builder
+            builderForValue) {
+      if (telephonyTransferCallBuilder_ == null) {
+        message_ = builderForValue.build();
+        onChanged();
+      } else {
+        telephonyTransferCallBuilder_.setMessage(builderForValue.build());
+      }
+      messageCase_ = 18;
+      return this;
+    }
+    /**
+     *
+     *
+     * <pre>
+     * A signal that the client should transfer the phone call connected to
+     * this agent to a third-party endpoint.
+     * </pre>
+     *
+     * <code>
+     * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+     * </code>
+     */
+    public Builder mergeTelephonyTransferCall(
+        com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall value) {
+      if (telephonyTransferCallBuilder_ == null) {
+        if (messageCase_ == 18
+            && message_
+                != com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+                    .getDefaultInstance()) {
+          message_ =
+              com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+                  .newBuilder(
+                      (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+                          message_)
+                  .mergeFrom(value)
+                  .buildPartial();
+        } else {
+          message_ = value;
+        }
+        onChanged();
+      } else {
+        if (messageCase_ == 18) {
+          telephonyTransferCallBuilder_.mergeFrom(value);
+        }
+        telephonyTransferCallBuilder_.setMessage(value);
+      }
+      messageCase_ = 18;
+      return this;
+    }
+    /**
+     *
+     *
+     * <pre>
+     * A signal that the client should transfer the phone call connected to
+     * this agent to a third-party endpoint.
+     * </pre>
+     *
+     * <code>
+     * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+     * </code>
+     */
+    public Builder clearTelephonyTransferCall() {
+      if (telephonyTransferCallBuilder_ == null) {
+        if (messageCase_ == 18) {
+          messageCase_ = 0;
+          message_ = null;
+          onChanged();
+        }
+      } else {
+        if (messageCase_ == 18) {
+          messageCase_ = 0;
+          message_ = null;
+        }
+        telephonyTransferCallBuilder_.clear();
+      }
+      return this;
+    }
+    /**
+     *
+     *
+     * <pre>
+     * A signal that the client should transfer the phone call connected to
+     * this agent to a third-party endpoint.
+     * </pre>
+     *
+     * <code>
+     * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+     * </code>
+     */
+    public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall.Builder
+        getTelephonyTransferCallBuilder() {
+      return getTelephonyTransferCallFieldBuilder().getBuilder();
+    }
+    /**
+     *
+     *
+     * <pre>
+     * A signal that the client should transfer the phone call connected to
+     * this agent to a third-party endpoint.
+     * </pre>
+     *
+     * <code>
+     * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+     * </code>
+     */
+    @java.lang.Override
+    public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCallOrBuilder
+        getTelephonyTransferCallOrBuilder() {
+      if ((messageCase_ == 18) && (telephonyTransferCallBuilder_ != null)) {
+        return telephonyTransferCallBuilder_.getMessageOrBuilder();
+      } else {
+        if (messageCase_ == 18) {
+          return (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+              message_;
+        }
+        return com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+            .getDefaultInstance();
+      }
+    }
+    /**
+     *
+     *
+     * <pre>
+     * A signal that the client should transfer the phone call connected to
+     * this agent to a third-party endpoint.
+     * </pre>
+     *
+     * <code>
+     * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+     * </code>
+     */
+    private com.google.protobuf.SingleFieldBuilderV3<
+            com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall,
+            com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall.Builder,
+            com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCallOrBuilder>
+        getTelephonyTransferCallFieldBuilder() {
+      if (telephonyTransferCallBuilder_ == null) {
+        if (!(messageCase_ == 18)) {
+          message_ =
+              com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+                  .getDefaultInstance();
+        }
+        telephonyTransferCallBuilder_ =
+            new com.google.protobuf.SingleFieldBuilderV3<
+                com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall,
+                com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+                    .Builder,
+                com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage
+                    .TelephonyTransferCallOrBuilder>(
+                (com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall)
+                    message_,
+                getParentForChildren(),
+                isClean());
+        message_ = null;
+      }
+      messageCase_ = 18;
+      onChanged();
+      ;
+      return telephonyTransferCallBuilder_;
+    }
+
     @java.lang.Override
     public final Builder setUnknownFields(final com.google.protobuf.UnknownFieldSet unknownFields) {
       return super.setUnknownFields(unknownFields);
diff --git a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessageOrBuilder.java b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessageOrBuilder.java
index 989651d29..e696ce060 100644
--- a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessageOrBuilder.java
+++ b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessageOrBuilder.java
@@ -375,5 +375,51 @@ public interface ResponseMessageOrBuilder
   com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.MixedAudioOrBuilder
       getMixedAudioOrBuilder();
 
+  /**
+   *
+   *
+   * <pre>
+   * A signal that the client should transfer the phone call connected to
+   * this agent to a third-party endpoint.
+   * </pre>
+   *
+   * <code>
+   * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+   * </code>
+   *
+   * @return Whether the telephonyTransferCall field is set.
+   */
+  boolean hasTelephonyTransferCall();
+  /**
+   *
+   *
+   * <pre>
+   * A signal that the client should transfer the phone call connected to
+   * this agent to a third-party endpoint.
+   * </pre>
+   *
+   * <code>
+   * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+   * </code>
+   *
+   * @return The telephonyTransferCall.
+   */
+  com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall
+      getTelephonyTransferCall();
+  /**
+   *
+   *
+   * <pre>
+   * A signal that the client should transfer the phone call connected to
+   * this agent to a third-party endpoint.
+   * </pre>
+   *
+   * <code>
+   * .google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCall telephony_transfer_call = 18;
+   * </code>
+   */
+  com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.TelephonyTransferCallOrBuilder
+      getTelephonyTransferCallOrBuilder();
+
   public com.google.cloud.dialogflow.cx.v3beta1.ResponseMessage.MessageCase getMessageCase();
 }
diff --git a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessageProto.java b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessageProto.java
index dc3c369c1..169d43879 100644
--- a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessageProto.java
+++ b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/java/com/google/cloud/dialogflow/cx/v3beta1/ResponseMessageProto.java
@@ -63,6 +63,10 @@ public static void registerAllExtensions(com.google.protobuf.ExtensionRegistry r
       internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_MixedAudio_Segment_descriptor;
   static final com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
       internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_MixedAudio_Segment_fieldAccessorTable;
+  static final com.google.protobuf.Descriptors.Descriptor
+      internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_TelephonyTransferCall_descriptor;
+  static final com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+      internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_TelephonyTransferCall_fieldAccessorTable;
 
   public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
     return descriptor;
@@ -76,7 +80,7 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
           + "ponse_message.proto\022\"google.cloud.dialog"
           + "flow.cx.v3beta1\032\037google/api/field_behavi"
           + "or.proto\032\034google/protobuf/struct.proto\032\034"
-          + "google/api/annotations.proto\"\255\n\n\017Respons"
+          + "google/api/annotations.proto\"\330\013\n\017Respons"
           + "eMessage\022H\n\004text\030\001 \001(\01328.google.cloud.di"
           + "alogflow.cx.v3beta1.ResponseMessage.Text"
           + "H\000\022*\n\007payload\030\002 \001(\0132\027.google.protobuf.St"
@@ -94,28 +98,32 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
           + "loud.dialogflow.cx.v3beta1.ResponseMessa"
           + "ge.PlayAudioH\000\022Z\n\013mixed_audio\030\r \001(\0132>.go"
           + "ogle.cloud.dialogflow.cx.v3beta1.Respons"
-          + "eMessage.MixedAudioB\003\340A\003H\000\032C\n\004Text\022\021\n\004te"
-          + "xt\030\001 \003(\tB\003\340A\002\022(\n\033allow_playback_interrup"
-          + "tion\030\002 \001(\010B\003\340A\003\032=\n\020LiveAgentHandoff\022)\n\010m"
-          + "etadata\030\001 \001(\0132\027.google.protobuf.Struct\032@"
-          + "\n\023ConversationSuccess\022)\n\010metadata\030\001 \001(\0132"
-          + "\027.google.protobuf.Struct\032e\n\017OutputAudioT"
-          + "ext\022\016\n\004text\030\001 \001(\tH\000\022\016\n\004ssml\030\002 \001(\tH\000\022(\n\033a"
-          + "llow_playback_interruption\030\003 \001(\010B\003\340A\003B\010\n"
-          + "\006source\032\020\n\016EndInteraction\032M\n\tPlayAudio\022\026"
-          + "\n\taudio_uri\030\001 \001(\tB\003\340A\002\022(\n\033allow_playback"
-          + "_interruption\030\002 \001(\010B\003\340A\003\032\306\001\n\nMixedAudio\022"
-          + "X\n\010segments\030\001 \003(\0132F.google.cloud.dialogf"
-          + "low.cx.v3beta1.ResponseMessage.MixedAudi"
-          + "o.Segment\032^\n\007Segment\022\017\n\005audio\030\001 \001(\014H\000\022\r\n"
-          + "\003uri\030\002 \001(\tH\000\022(\n\033allow_playback_interrupt"
-          + "ion\030\003 \001(\010B\003\340A\003B\t\n\007contentB\t\n\007messageB\334\001\n"
-          + "&com.google.cloud.dialogflow.cx.v3beta1B"
-          + "\024ResponseMessageProtoP\001ZDgoogle.golang.o"
-          + "rg/genproto/googleapis/cloud/dialogflow/"
-          + "cx/v3beta1;cx\370\001\001\242\002\002DF\252\002\"Google.Cloud.Dia"
-          + "logflow.Cx.V3Beta1\352\002&Google::Cloud::Dial"
-          + "ogflow::CX::V3beta1b\006proto3"
+          + "eMessage.MixedAudioB\003\340A\003H\000\022l\n\027telephony_"
+          + "transfer_call\030\022 \001(\0132I.google.cloud.dialo"
+          + "gflow.cx.v3beta1.ResponseMessage.Telepho"
+          + "nyTransferCallH\000\032C\n\004Text\022\021\n\004text\030\001 \003(\tB\003"
+          + "\340A\002\022(\n\033allow_playback_interruption\030\002 \001(\010"
+          + "B\003\340A\003\032=\n\020LiveAgentHandoff\022)\n\010metadata\030\001 "
+          + "\001(\0132\027.google.protobuf.Struct\032@\n\023Conversa"
+          + "tionSuccess\022)\n\010metadata\030\001 \001(\0132\027.google.p"
+          + "rotobuf.Struct\032e\n\017OutputAudioText\022\016\n\004tex"
+          + "t\030\001 \001(\tH\000\022\016\n\004ssml\030\002 \001(\tH\000\022(\n\033allow_playb"
+          + "ack_interruption\030\003 \001(\010B\003\340A\003B\010\n\006source\032\020\n"
+          + "\016EndInteraction\032M\n\tPlayAudio\022\026\n\taudio_ur"
+          + "i\030\001 \001(\tB\003\340A\002\022(\n\033allow_playback_interrupt"
+          + "ion\030\002 \001(\010B\003\340A\003\032\306\001\n\nMixedAudio\022X\n\010segment"
+          + "s\030\001 \003(\0132F.google.cloud.dialogflow.cx.v3b"
+          + "eta1.ResponseMessage.MixedAudio.Segment\032"
+          + "^\n\007Segment\022\017\n\005audio\030\001 \001(\014H\000\022\r\n\003uri\030\002 \001(\t"
+          + "H\000\022(\n\033allow_playback_interruption\030\003 \001(\010B"
+          + "\003\340A\003B\t\n\007content\032;\n\025TelephonyTransferCall"
+          + "\022\026\n\014phone_number\030\001 \001(\tH\000B\n\n\010endpointB\t\n\007"
+          + "messageB\334\001\n&com.google.cloud.dialogflow."
+          + "cx.v3beta1B\024ResponseMessageProtoP\001ZDgoog"
+          + "le.golang.org/genproto/googleapis/cloud/"
+          + "dialogflow/cx/v3beta1;cx\370\001\001\242\002\002DF\252\002\"Googl"
+          + "e.Cloud.Dialogflow.Cx.V3Beta1\352\002&Google::"
+          + "Cloud::Dialogflow::CX::V3beta1b\006proto3"
     };
     descriptor =
         com.google.protobuf.Descriptors.FileDescriptor.internalBuildGeneratedFileFrom(
@@ -139,6 +147,7 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
               "EndInteraction",
               "PlayAudio",
               "MixedAudio",
+              "TelephonyTransferCall",
               "Message",
             });
     internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_Text_descriptor =
@@ -219,6 +228,16 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
             new java.lang.String[] {
               "Audio", "Uri", "AllowPlaybackInterruption", "Content",
             });
+    internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_TelephonyTransferCall_descriptor =
+        internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_descriptor
+            .getNestedTypes()
+            .get(7);
+    internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_TelephonyTransferCall_fieldAccessorTable =
+        new com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
+            internal_static_google_cloud_dialogflow_cx_v3beta1_ResponseMessage_TelephonyTransferCall_descriptor,
+            new java.lang.String[] {
+              "PhoneNumber", "Endpoint",
+            });
     com.google.protobuf.ExtensionRegistry registry =
         com.google.protobuf.ExtensionRegistry.newInstance();
     registry.add(com.google.api.FieldBehaviorProto.fieldBehavior);
diff --git a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/proto/google/cloud/dialogflow/cx/v3beta1/environment.proto b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/proto/google/cloud/dialogflow/cx/v3beta1/environment.proto
index 61bf0648e..a53460eae 100644
--- a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/proto/google/cloud/dialogflow/cx/v3beta1/environment.proto
+++ b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/proto/google/cloud/dialogflow/cx/v3beta1/environment.proto
@@ -21,6 +21,7 @@ import "google/api/client.proto";
 import "google/api/field_behavior.proto";
 import "google/api/resource.proto";
 import "google/cloud/dialogflow/cx/v3beta1/test_case.proto";
+import "google/cloud/dialogflow/cx/v3beta1/webhook.proto";
 import "google/longrunning/operations.proto";
 import "google/protobuf/empty.proto";
 import "google/protobuf/field_mask.proto";
diff --git a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/proto/google/cloud/dialogflow/cx/v3beta1/response_message.proto b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/proto/google/cloud/dialogflow/cx/v3beta1/response_message.proto
index d9331eb42..f6b747f1d 100644
--- a/proto-google-cloud-dialogflow-cx-v3beta1/src/main/proto/google/cloud/dialogflow/cx/v3beta1/response_message.proto
+++ b/proto-google-cloud-dialogflow-cx-v3beta1/src/main/proto/google/cloud/dialogflow/cx/v3beta1/response_message.proto
@@ -164,6 +164,17 @@ message ResponseMessage {
     repeated Segment segments = 1;
   }
 
+  // Represents the signal that telles the client to transfer the phone call
+  // connected to the agent to a third-party endpoint.
+  message TelephonyTransferCall {
+    // Endpoint to transfer the call to.
+    oneof endpoint {
+      // Transfer the call to a phone number
+      // in [E.164 format](https://en.wikipedia.org/wiki/E.164).
+      string phone_number = 1;
+    }
+  }
+
   // Required. The rich response message.
   oneof message {
     // Returns a text response.
@@ -202,5 +213,9 @@ message ResponseMessage {
     // This message is generated by Dialogflow only and not supposed to be
     // defined by the user.
     MixedAudio mixed_audio = 13 [(google.api.field_behavior) = OUTPUT_ONLY];
+
+    // A signal that the client should transfer the phone call connected to
+    // this agent to a third-party endpoint.
+    TelephonyTransferCall telephony_transfer_call = 18;
   }
 }