Merge pull request #38607 from BerriAI/litellm_fix_files_pre_call_hook

fix(proxy): trigger async_pre_call_hook on POST /v1/files uploads

litellm/proxy/openai_files_endpoints/files_endpoints.py

@@ -8,7 +8,7 @@
 import asyncio
 import traceback
 from collections.abc import Mapping
-from typing import Any, BinaryIO, Final, cast, get_args
+from typing import Any, BinaryIO, Final, TypedDict, cast, get_args
 
 import httpx
 from fastapi import (
@@ -23,6 +23,7 @@ from fastapi import (
     status,
 )
 from pydantic import TypeAdapter
+from typing_extensions import ReadOnly
 
 import litellm
 from litellm import CreateFileRequest, get_secret_str
@@ -83,6 +84,13 @@ router: Final = APIRouter()
 
 _MAX_BATCH_FILE_SIZE_MB_ADAPTER: Final = TypeAdapter(int | None)
 
+
+class UploadedFileInfo(TypedDict):
+    filename: ReadOnly[str | None]
+    content_type: ReadOnly[str | None]
+    size: ReadOnly[int | None]
+
+
 files_config = None
 
 
@@ -526,6 +534,22 @@ async def create_file(
             proxy_config=proxy_config,
         )
 
+        uploaded_file_info: Final[UploadedFileInfo] = {
+            "filename": file.filename,
+            "content_type": file.content_type,
+            "size": file.size,
+        }
+        data["purpose"] = purpose
+        data["file"] = uploaded_file_info
+        hooked_data: Final = await proxy_logging_obj.pre_call_hook(
+            user_api_key_dict=user_api_key_dict,
+            data=data,
+            call_type="acreate_file",
+        )
+        data = hooked_data if hooked_data is not None else data
+        data.pop("purpose", None)
+        data.pop("file", None)
+
         # /v1/files stores its proxy metadata under litellm_metadata, not metadata
         request_metadata: Final = data.get("metadata") or data.get("litellm_metadata") or EMPTY_MAPPING
         scan_result: Final = await _scan_batch_upload(

litellm/types/utils.py

@@ -544,6 +544,8 @@ CallTypesLiteral = Literal[
     "_arealtime",
     "create_batch",
     "acreate_batch",
+    "create_file",
+    "acreate_file",
     "pass_through_endpoint",
     "allm_passthrough_route",
     "anthropic_messages",

tests/test_litellm/proxy/openai_files_endpoint/test_files_endpoint.py

@@ -4476,3 +4476,82 @@ def test_scoped_list_files_still_resolves_deployment_credentials(
     provider_list.assert_awaited_once()
     assert provider_list.await_args.kwargs["custom_llm_provider"] == "openai"
     assert provider_list.await_args.kwargs["api_key"] == "openai_api_key"
+
+
+def _post_user_data_file() -> httpx.Response:
+    return client.post(
+        "/v1/files",
+        files={"file": ("labels.jsonl", b'{"label": "restricted"}', "application/json")},
+        data={"purpose": "user_data"},
+        headers={"Authorization": "Bearer test-key"},
+    )
+
+
+def _setup_create_file_over_pre_call_hook(monkeypatch, llm_router, hook):
+    setup_proxy_logging_object(monkeypatch, llm_router)
+    monkeypatch.setattr("litellm.proxy.proxy_server.llm_router", llm_router)
+    monkeypatch.setattr(litellm, "callbacks", [hook])
+    monkeypatch.setattr(
+        "litellm.proxy.openai_files_endpoints.files_endpoints.files_config",
+        [{"custom_llm_provider": "openai", "api_key": "sk-test"}],
+    )
+    return respx.post("https://api.openai.com/v1/files").mock(
+        return_value=respx.MockResponse(
+            status_code=200,
+            json={
+                "id": "file-hooked",
+                "object": "file",
+                "bytes": 23,
+                "created_at": 1234567890,
+                "filename": "labels.jsonl",
+                "purpose": "user_data",
+                "status": "uploaded",
+            },
+        )
+    )
+
+
+@respx.mock
+def test_create_file_triggers_async_pre_call_hook(monkeypatch, llm_router: Router):
+    """`POST /v1/files` must run `async_pre_call_hook` so a hook can inspect the upload
+    before it reaches the provider (LIT-5916)."""
+    from litellm.integrations.custom_logger import CustomLogger
+
+    recorded: dict = {}
+
+    class RecordingHook(CustomLogger):
+        async def async_pre_call_hook(self, user_api_key_dict, cache, data, call_type):
+            recorded["call_type"] = call_type
+            recorded["purpose"] = data.get("purpose")
+            recorded["file"] = data.get("file")
+
+    provider_route = _setup_create_file_over_pre_call_hook(monkeypatch, llm_router, RecordingHook())
+
+    response = _post_user_data_file()
+
+    assert response.status_code == 200, response.text
+    assert recorded["call_type"] == "acreate_file"
+    assert recorded["purpose"] == "user_data"
+    assert recorded["file"]["filename"] == "labels.jsonl"
+    assert provider_route.call_count == 1
+    forwarded_body = provider_route.calls.last.request.content
+    assert b"user_data" in forwarded_body
+    assert b"labels.jsonl" in forwarded_body
+
+
+@respx.mock
+def test_create_file_async_pre_call_hook_rejection_blocks_upload(monkeypatch, llm_router: Router):
+    """A hook rejecting the upload must 400 before the file reaches the provider."""
+    from litellm.integrations.custom_logger import CustomLogger
+
+    class RejectingHook(CustomLogger):
+        async def async_pre_call_hook(self, user_api_key_dict, cache, data, call_type):
+            return "file upload not allowed"
+
+    provider_route = _setup_create_file_over_pre_call_hook(monkeypatch, llm_router, RejectingHook())
+
+    response = _post_user_data_file()
+
+    assert response.status_code == 400, response.text
+    assert "file upload not allowed" in response.text
+    assert provider_route.call_count == 0