fix(python): Remove oauth-token-override config flag (#11113)

OAuth token override is now always enabled for OAuth client credentials flows,
allowing users to authenticate with either client_id/client_secret OR a
pre-generated bearer token directly via the token parameter without any
configuration.

- Remove oauth_token_override field from SDKCustomConfig
- Update root_client_generator.py to always enable token override for OAuth
- Update readme_snippet_builder.py to detect OAuth from IR instead of config
- Remove token-override seed fixtures (now merged with no-custom-config)
- Regenerate seed output for oauth-client-credentials fixtures

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

Author: tjb9dc

generators/python/sdk/versions.yml

@@ -1,5 +1,15 @@
 # yaml-language-server: $schema=../../../fern-versions-yml.schema.json
 # For unreleased changes, use unreleased.yml
+- version: 4.44.1
+  changelogEntry:
+    - summary: |
+        Remove `oauth-token-override` config flag. OAuth token override is now always enabled for OAuth client
+        credentials flows, allowing users to authenticate with either client_id/client_secret OR a pre-generated
+        bearer token directly via the `token` parameter without any configuration.
+      type: fix
+  createdAt: "2025-12-09"
+  irVersion: 61
+
 - version: 4.44.0
   changelogEntry:
     - summary: |

generators/python/src/fern_python/generator_cli/generator_cli.py

@@ -96,15 +96,13 @@ def generate_readme(
         github_installation_token: Optional[str] = None,
         pagination_enabled: Union[bool, None] = False,
         websocket_enabled: bool = False,
-        oauth_token_override: bool = False,
     ) -> str:
         readme_snippet_builder = ReadmeSnippetBuilder(
             ir=self._ir,
             package_name=self._package_name,
             snippets=snippets,
             pagination_enabled=pagination_enabled,
             websocket_enabled=websocket_enabled,
-            oauth_token_override=oauth_token_override,
             generated_root_client=generated_root_client,
             api_error_reference=self._context.core_utilities.get_reference_to_api_error(as_snippet=True),
             endpoint_metadata=self._endpoint_metadata,

generators/python/src/fern_python/generator_cli/readme_snippet_builder.py

@@ -44,7 +44,6 @@ def __init__(
         source_file_factory: SourceFileFactory,
         pagination_enabled: Optional[bool] = False,
         websocket_enabled: Optional[bool] = False,
-        oauth_token_override: Optional[bool] = False,
     ):
         self._ir = ir
         self._package_name = package_name
@@ -54,7 +53,8 @@ def __init__(
         # flags and how many places need this context.
         self._pagination_enabled = pagination_enabled
         self._websocket_enabled = websocket_enabled
-        self._oauth_token_override = oauth_token_override
+        # Determine if OAuth client credentials is enabled from the IR
+        self._is_oauth_client_credentials = self._check_oauth_client_credentials(ir)
 
         self._source_file_factory = source_file_factory
 
@@ -84,7 +84,7 @@ def build_readme_snippets(self) -> Dict[generatorcli.feature.FeatureId, List[str
         if self._websocket_enabled:
             snippets[ReadmeSnippetBuilder.WEBSOCKETS_FEATURE_ID] = self._build_websocket_snippets()
 
-        if self._oauth_token_override:
+        if self._is_oauth_client_credentials:
             snippets[ReadmeSnippetBuilder.OAUTH_TOKEN_OVERRIDE_FEATURE_ID] = self._build_oauth_token_override_snippets()
 
         snippets[ReadmeSnippetBuilder.ACCESS_RAW_RESPONSE_DATA_FEATURE_ID] = (
@@ -545,6 +545,18 @@ def _client_writer_credentials(writer: AST.NodeWriter) -> None:
             print(f"Failed to generate oauth token override snippets with exception {e}")
             return []
 
+    def _check_oauth_client_credentials(self, ir: ir_types.IntermediateRepresentation) -> bool:
+        """Check if OAuth client credentials is configured in the IR."""
+        if ir.auth is None:
+            return False
+        for scheme in ir.auth.schemes:
+            scheme_union = scheme.get_as_union()
+            if scheme_union.type == "oauth":
+                oauth_config = scheme_union.configuration.get_as_union()
+                if oauth_config.type == "clientCredentials":
+                    return True
+        return False
+
     def _build_endpoint_feature_map(
         self, ir: ir_types.IntermediateRepresentation
     ) -> Dict[generatorcli.feature.FeatureId, List[ir_types.EndpointId]]:

generators/python/src/fern_python/generators/sdk/client_generator/root_client_generator.py

@@ -127,10 +127,6 @@ class SDKCustomConfig(pydantic.BaseModel):
 
     custom_pager_name: Optional[str] = None
 
-    # When enabled for OAuth client credentials, allows users to provide
-    # either client_id/client_secret OR a pre-generated token directly.
-    oauth_token_override: bool = False
-
     class Config:
         extra = pydantic.Extra.forbid
 
@@ -140,8 +136,6 @@ def parse_obj(cls, obj: Any) -> "SDKCustomConfig":
             obj = obj.copy()
             if "custom-pager-name" in obj and "custom_pager_name" not in obj:
                 obj["custom_pager_name"] = obj.pop("custom-pager-name")
-            if "oauth-token-override" in obj and "oauth_token_override" not in obj:
-                obj["oauth_token_override"] = obj.pop("oauth-token-override")
 
         obj = super().parse_obj(obj)
 

generators/python/src/fern_python/generators/sdk/custom_config.py

@@ -624,7 +624,6 @@ def _write_readme(
             pagination_enabled=context.generator_config.generate_paginated_clients,
             websocket_enabled=write_websocket_snippets,
             generated_root_client=generated_root_client,
-            oauth_token_override=context.custom_config.oauth_token_override,
         )
         project.add_file(
             os.path.join(

generators/python/src/fern_python/generators/sdk/sdk_generator.py

@@ -92,7 +92,7 @@ def test_generated_root_client_builder_instantiations_list() -> None:
     builder = _create_test_builder()
     generated_root_client = builder.build()
 
-    # Without oauth_token_override, there should be exactly one instantiation
+    # Without OAuth client credentials, there should be exactly one instantiation
     assert len(generated_root_client.sync_instantiations) == 1
     assert len(generated_root_client.async_instantiations) == 1
 
@@ -106,12 +106,12 @@ def test_generated_root_client_builder_instantiations_list() -> None:
     assert snippet_from_property.to_str() == snippet_from_list.to_str()
 
 
-def test_generated_root_client_builder_with_oauth_token_override() -> None:
-    """Test that oauth_token_override adds a second token-based instantiation."""
+def test_generated_root_client_builder_with_oauth_client_credentials() -> None:
+    """Test that OAuth client credentials adds a second token-based instantiation."""
     builder = _create_test_builder(oauth_token_override=True)
     generated_root_client = builder.build()
 
-    # With oauth_token_override, there should be two instantiations
+    # With OAuth client credentials, there should be two instantiations
     assert len(generated_root_client.sync_instantiations) == 2
     assert len(generated_root_client.async_instantiations) == 2