diff --git a/google/genai/_gaos/_hooks/google_genai_auth.py b/google/genai/_gaos/_hooks/google_genai_auth.py
index eaa51a84c..64687f78d 100644
--- a/google/genai/_gaos/_hooks/google_genai_auth.py
+++ b/google/genai/_gaos/_hooks/google_genai_auth.py
@@ -67,7 +67,6 @@ def before_request(
         security = _resolve_security(hook_ctx.security_source)
 
         _apply_default_headers(security, request)
-        _apply_api_revision(hook_ctx, request)
         _apply_user_project(hook_ctx, request)
         _apply_auth(security, request)
 
@@ -105,15 +104,6 @@ def _apply_default_headers(
             request.headers[key] = value
 
 
-def _apply_api_revision(
-    hook_ctx: BeforeRequestContext, request: httpx.Request
-) -> None:
-    if request.headers.get("Api-Revision") is not None:
-        return
-
-    api_revision = hook_ctx.config.globals.api_revision
-    request.headers["Api-Revision"] = api_revision or GOOGLE_GENAI_API_REVISION
-
 
 def _apply_user_project(
     hook_ctx: BeforeRequestContext, request: httpx.Request
diff --git a/google/genai/_gaos/models/internal/globals.py b/google/genai/_gaos/models/internal/globals.py
index 3dca99074..a6f03da5a 100644
--- a/google/genai/_gaos/models/internal/globals.py
+++ b/google/genai/_gaos/models/internal/globals.py
@@ -28,8 +28,6 @@
 class GlobalsTypedDict(TypedDict):
     api_version: NotRequired[str]
     r"""Which version of the API to use."""
-    api_revision: NotRequired[str]
-    r"""API revision header to send with Google GenAI API requests."""
     user_project: NotRequired[str]
     r"""Quota project header to send with Google GenAI API requests."""
 
@@ -41,13 +39,6 @@ class Globals(BaseModel):
     ] = None
     r"""Which version of the API to use."""
 
-    api_revision: Annotated[
-        Optional[str],
-        pydantic.Field(alias="Api-Revision"),
-        FieldMetadata(header=HeaderMetadata(style="simple", explode=False)),
-    ] = None
-    r"""API revision header to send with Google GenAI API requests."""
-
     user_project: Annotated[
         Optional[str],
         pydantic.Field(alias="x-goog-user-project"),
@@ -57,7 +48,7 @@ class Globals(BaseModel):
 
     @model_serializer(mode="wrap")
     def serialize_model(self, handler):
-        optional_fields = set(["api_version", "api_revision", "user_project"])
+        optional_fields = set(["api_version", "user_project"])
         serialized = handler(self)
         m = {}
 
diff --git a/google/genai/_gaos/sdk.py b/google/genai/_gaos/sdk.py
index 218a74d54..452882316 100644
--- a/google/genai/_gaos/sdk.py
+++ b/google/genai/_gaos/sdk.py
@@ -67,7 +67,6 @@ def __init__(
         self,
         security: Optional[Union[types.Security, Callable[[], types.Security]]] = None,
         api_version: Optional[str] = None,
-        api_revision: Optional[str] = None,
         user_project: Optional[str] = None,
         server_idx: Optional[int] = None,
         url_params: Optional[Dict[str, str]] = None,
@@ -81,7 +80,6 @@ def __init__(
 
         :param security: The security details required for authentication
         :param api_version: Configures the api_version parameter for all supported operations
-        :param api_revision: Configures the api_revision parameter for all supported operations
         :param user_project: Configures the user_project parameter for all supported operations
         :param server_idx: The index of the server to use for all methods
         :param server_url: The server URL to use for all methods
@@ -110,9 +108,6 @@ def __init__(
             api_version=utils.get_global_from_env(
                 api_version, "GOOGLE_GENAI_API_VERSION", str
             ),
-            api_revision=utils.get_global_from_env(
-                api_revision, "GOOGLE_GENAI_API_REVISION", str
-            ),
             user_project=utils.get_global_from_env(
                 user_project, "GOOGLE_GENAI_USER_PROJECT", str
             ),
@@ -263,7 +258,6 @@ def __init__(
         self,
         security: Optional[Union[types.Security, Callable[[], types.Security]]] = None,
         api_version: Optional[str] = None,
-        api_revision: Optional[str] = None,
         user_project: Optional[str] = None,
         server_idx: Optional[int] = None,
         url_params: Optional[Dict[str, str]] = None,
@@ -277,7 +271,6 @@ def __init__(
 
         :param security: The security details required for authentication
         :param api_version: Configures the api_version parameter for all supported operations
-        :param api_revision: Configures the api_revision parameter for all supported operations
         :param user_project: Configures the user_project parameter for all supported operations
         :param server_idx: The index of the server to use for all methods
         :param server_url: The server URL to use for all methods
@@ -304,9 +297,6 @@ def __init__(
             api_version=utils.get_global_from_env(
                 api_version, "GOOGLE_GENAI_API_VERSION", str
             ),
-            api_revision=utils.get_global_from_env(
-                api_revision, "GOOGLE_GENAI_API_REVISION", str
-            ),
             user_project=utils.get_global_from_env(
                 user_project, "GOOGLE_GENAI_USER_PROJECT", str
             ),