diff --git a/google/iam/credentials/v1/iamcredentials_gapic.legacy.yaml b/google/iam/credentials/v1/iamcredentials_gapic.legacy.yaml
new file mode 100644
index 00000000..7524a185
--- /dev/null
+++ b/google/iam/credentials/v1/iamcredentials_gapic.legacy.yaml
@@ -0,0 +1,133 @@
+type: com.google.api.codegen.ConfigProto
+config_schema_version: 1.0.0
+# The settings of generated code in a specific language.
+language_settings:
+  java:
+    package_name: com.google.cloud.iam.credentials.v1
+  python:
+    package_name: google.cloud.iam_credentials_v1.gapic
+  go:
+    package_name: cloud.google.com/go/iam/credentials/apiv1
+  csharp:
+    package_name: Google.Iam.Credentials.V1
+  ruby:
+    package_name: Google::Cloud::Iam::Credentials::V1
+  php:
+    package_name: Google\Cloud\Iam\Credentials\V1
+  nodejs:
+    package_name: credentials.v1
+# A list of API interface configurations.
+interfaces:
+# The fully qualified name of the API interface.
+- name: google.iam.credentials.v1.IAMCredentials
+  # A list of resource collection configurations.
+  # Consists of a name_pattern and an entity_name.
+  # The name_pattern is a pattern to describe the names of the resources of this
+  # collection, using the platform's conventions for URI patterns. A generator
+  # may use this to generate methods to compose and decompose such names. The
+  # pattern should use named placeholders as in `shelves/{shelf}/books/{book}`;
+  # those will be taken as hints for the parameter names of the generated
+  # methods. If empty, no name methods are generated.
+  # The entity_name is the name to be used as a basis for generated methods and
+  # classes.
+  collections:
+  - name_pattern: projects/{project}/serviceAccounts/{service_account}
+    entity_name: service_account
+  # Definition for retryable codes.
+  retry_codes_def:
+  - name: idempotent
+    retry_codes:
+    - UNAVAILABLE
+    - DEADLINE_EXCEEDED
+  - name: non_idempotent
+    retry_codes: []
+  # Definition for retry/backoff parameters.
+  retry_params_def:
+  - name: default
+    initial_retry_delay_millis: 100
+    retry_delay_multiplier: 1.3
+    max_retry_delay_millis: 60000
+    initial_rpc_timeout_millis: 20000
+    rpc_timeout_multiplier: 1
+    max_rpc_timeout_millis: 20000
+    total_timeout_millis: 600000
+  methods:
+  - name: GenerateAccessToken
+    flattening:
+      groups:
+      - parameters:
+        - name
+        - delegates
+        - scope
+        - lifetime
+    required_fields:
+    - name
+    - scope
+    retry_codes_name: idempotent
+    retry_params_name: default
+    field_name_patterns:
+      name: service_account
+    timeout_millis: 60000
+    resource_name_treatment: STATIC_TYPES
+  - name: GenerateIdToken
+    flattening:
+      groups:
+      - parameters:
+        - name
+        - delegates
+        - audience
+        - include_email
+    required_fields:
+    - name
+    - audience
+    retry_codes_name: idempotent
+    retry_params_name: default
+    field_name_patterns:
+      name: service_account
+    timeout_millis: 60000
+    resource_name_treatment: STATIC_TYPES
+  - name: SignBlob
+    flattening:
+      groups:
+      - parameters:
+        - name
+        - delegates
+        - payload
+    required_fields:
+    - name
+    - payload
+    retry_codes_name: idempotent
+    retry_params_name: default
+    field_name_patterns:
+      name: service_account
+    timeout_millis: 60000
+    resource_name_treatment: STATIC_TYPES
+  - name: SignJwt
+    flattening:
+      groups:
+      - parameters:
+        - name
+        - delegates
+        - payload
+    required_fields:
+    - name
+    - payload
+    retry_codes_name: idempotent
+    retry_params_name: default
+    field_name_patterns:
+      name: service_account
+    timeout_millis: 60000
+    resource_name_treatment: STATIC_TYPES
+resource_name_generation:
+- message_name: GenerateAccessTokenRequest
+  field_entity_map:
+    name: service_account
+- message_name: GenerateIdTokenRequest
+  field_entity_map:
+    name: service_account
+- message_name: SignBlobRequest
+  field_entity_map:
+    name: service_account
+- message_name: SignJwtRequest
+  field_entity_map:
+    name: service_account
diff --git a/google/iam/credentials/v1/iamcredentials_gapic.yaml b/google/iam/credentials/v1/iamcredentials_gapic.yaml
index 7524a185..6368f96b 100644
--- a/google/iam/credentials/v1/iamcredentials_gapic.yaml
+++ b/google/iam/credentials/v1/iamcredentials_gapic.yaml
@@ -1,5 +1,5 @@
 type: com.google.api.codegen.ConfigProto
-config_schema_version: 1.0.0
+config_schema_version: 2.0.0
 # The settings of generated code in a specific language.
 language_settings:
   java:
@@ -20,114 +20,12 @@ language_settings:
 interfaces:
 # The fully qualified name of the API interface.
 - name: google.iam.credentials.v1.IAMCredentials
-  # A list of resource collection configurations.
-  # Consists of a name_pattern and an entity_name.
-  # The name_pattern is a pattern to describe the names of the resources of this
-  # collection, using the platform's conventions for URI patterns. A generator
-  # may use this to generate methods to compose and decompose such names. The
-  # pattern should use named placeholders as in `shelves/{shelf}/books/{book}`;
-  # those will be taken as hints for the parameter names of the generated
-  # methods. If empty, no name methods are generated.
-  # The entity_name is the name to be used as a basis for generated methods and
-  # classes.
-  collections:
-  - name_pattern: projects/{project}/serviceAccounts/{service_account}
-    entity_name: service_account
-  # Definition for retryable codes.
-  retry_codes_def:
-  - name: idempotent
-    retry_codes:
-    - UNAVAILABLE
-    - DEADLINE_EXCEEDED
-  - name: non_idempotent
-    retry_codes: []
-  # Definition for retry/backoff parameters.
-  retry_params_def:
-  - name: default
-    initial_retry_delay_millis: 100
-    retry_delay_multiplier: 1.3
-    max_retry_delay_millis: 60000
-    initial_rpc_timeout_millis: 20000
-    rpc_timeout_multiplier: 1
-    max_rpc_timeout_millis: 20000
-    total_timeout_millis: 600000
   methods:
   - name: GenerateAccessToken
-    flattening:
-      groups:
-      - parameters:
-        - name
-        - delegates
-        - scope
-        - lifetime
-    required_fields:
-    - name
-    - scope
     retry_codes_name: idempotent
-    retry_params_name: default
-    field_name_patterns:
-      name: service_account
-    timeout_millis: 60000
-    resource_name_treatment: STATIC_TYPES
   - name: GenerateIdToken
-    flattening:
-      groups:
-      - parameters:
-        - name
-        - delegates
-        - audience
-        - include_email
-    required_fields:
-    - name
-    - audience
     retry_codes_name: idempotent
-    retry_params_name: default
-    field_name_patterns:
-      name: service_account
-    timeout_millis: 60000
-    resource_name_treatment: STATIC_TYPES
   - name: SignBlob
-    flattening:
-      groups:
-      - parameters:
-        - name
-        - delegates
-        - payload
-    required_fields:
-    - name
-    - payload
     retry_codes_name: idempotent
-    retry_params_name: default
-    field_name_patterns:
-      name: service_account
-    timeout_millis: 60000
-    resource_name_treatment: STATIC_TYPES
   - name: SignJwt
-    flattening:
-      groups:
-      - parameters:
-        - name
-        - delegates
-        - payload
-    required_fields:
-    - name
-    - payload
     retry_codes_name: idempotent
-    retry_params_name: default
-    field_name_patterns:
-      name: service_account
-    timeout_millis: 60000
-    resource_name_treatment: STATIC_TYPES
-resource_name_generation:
-- message_name: GenerateAccessTokenRequest
-  field_entity_map:
-    name: service_account
-- message_name: GenerateIdTokenRequest
-  field_entity_map:
-    name: service_account
-- message_name: SignBlobRequest
-  field_entity_map:
-    name: service_account
-- message_name: SignJwtRequest
-  field_entity_map:
-    name: service_account