fix(files): honor AsyncCursorPage returned by post_call_success_hook in list_files

litellm/proxy/openai_files_endpoints/files_endpoints.py

@@ -39,6 +39,8 @@
 )
 from litellm.proxy.utils import ProxyLogging, is_known_model
 from litellm.router import Router
+from openai.pagination import AsyncCursorPage
+
 from litellm.types.llms.openai import (
     CREATE_FILE_REQUESTS_PURPOSE,
     FileExpiresAfter,
@@ -1377,7 +1379,16 @@ async def list_files(
         _response = await proxy_logging_obj.post_call_success_hook(
             data=data, user_api_key_dict=user_api_key_dict, response=response
         )
-        if _response is not None and isinstance(_response, OpenAIFileObject):
+        # NOTE: the managed-files hook returns AsyncCursorPage for the list-files
+        # response (see enterprise/litellm_enterprise/proxy/hooks/managed_files.py:
+        # async_post_call_success_hook). Without AsyncCursorPage in this isinstance
+        # tuple the hook return value is discarded, and the unfiltered raw provider
+        # listing leaks back to the caller. The hook also mutates response.data in
+        # place which partially masks this, but breaks the moment any future hook
+        # returns a freshly-constructed page object.
+        if _response is not None and isinstance(
+            _response, (OpenAIFileObject, AsyncCursorPage)
+        ):
             response = _response
 
         ### ALERTING ###

tests/test_litellm/proxy/openai_files_endpoint/test_files_endpoint.py

@@ -1873,3 +1873,94 @@ async def _mock_afile_content(**kwargs):
     assert "stream" not in captured_kwargs
     mock_streaming_response.assert_not_awaited()
     proxy_logging_obj.post_call_failure_hook.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_list_files_uses_async_cursor_page_returned_by_post_call_hook(
+    monkeypatch, llm_router: Router
+):
+    """
+    Regression for LIT-3386 / GH #28294.
+
+    The managed-files hook (`async_post_call_success_hook`) returns an
+    `AsyncCursorPage` for GET /v1/files responses. Prior to the fix the
+    list_files endpoint only re-assigned `response` when the hook returned an
+    `OpenAIFileObject`, so any freshly-constructed page from the hook was
+    silently dropped and the unfiltered raw provider listing was returned to
+    the caller. This test asserts the hook-returned page reaches the client.
+    """
+    from openai.pagination import AsyncCursorPage
+    import litellm.proxy.proxy_server as ps
+    from litellm.proxy._types import LitellmUserRoles
+
+    setup_proxy_logging_object(monkeypatch, llm_router)
+    monkeypatch.setattr("litellm.proxy.proxy_server.llm_router", llm_router)
+
+    raw_provider_page = AsyncCursorPage(
+        data=[
+            OpenAIFileObject(
+                id="file-leaked-raw",
+                bytes=10,
+                created_at=1,
+                filename="raw.jsonl",
+                object="file",
+                purpose="batch",
+                status="processed",
+            ),
+            OpenAIFileObject(
+                id="file-owned-by-user",
+                bytes=10,
+                created_at=1,
+                filename="owned.jsonl",
+                object="file",
+                purpose="batch",
+                status="processed",
+            ),
+        ],
+    )
+
+    filtered_page = AsyncCursorPage(
+        data=[
+            OpenAIFileObject(
+                id="file-owned-by-user",
+                bytes=10,
+                created_at=1,
+                filename="owned.jsonl",
+                object="file",
+                purpose="batch",
+                status="processed",
+            ),
+        ],
+    )
+
+    monkeypatch.setattr(
+        litellm,
+        "afile_list",
+        AsyncMock(return_value=raw_provider_page),
+    )
+    monkeypatch.setattr(
+        ps.proxy_logging_obj,
+        "post_call_success_hook",
+        AsyncMock(return_value=filtered_page),
+    )
+
+    app.dependency_overrides[ps.user_api_key_auth] = lambda: UserAPIKeyAuth(
+        api_key="test-key",
+        user_role=LitellmUserRoles.PROXY_ADMIN,
+        user_id="test-user",
+    )
+
+    try:
+        response = client.get(
+            "/v1/files",
+            headers={"Authorization": "Bearer test-key"},
+        )
+    finally:
+        app.dependency_overrides.pop(ps.user_api_key_auth, None)
+
+    assert response.status_code == 200, response.text
+    body = response.json()
+    returned_ids = [item["id"] for item in body["data"]]
+    assert returned_ids == ["file-owned-by-user"], (
+        f"expected only owned file id, got {returned_ids}"
+    )