refac

backend/open_webui/main.py

@@ -1442,6 +1442,16 @@ async def check_url(request: Request, call_next):
             scheme="Bearer", credentials=request.cookies.get("token")
         )
 
+    # Fallback to x-api-key header for Anthropic Messages API routes
+    if request.state.token is None and request.headers.get("x-api-key"):
+        request_path = request.url.path
+        if request_path in ("/api/message", "/api/v1/messages"):
+            from fastapi.security import HTTPAuthorizationCredentials
+
+            request.state.token = HTTPAuthorizationCredentials(
+                scheme="Bearer", credentials=request.headers.get("x-api-key")
+            )
+
     request.state.enable_api_keys = app.state.config.ENABLE_API_KEYS
     response = await call_next(request)
     process_time = int(time.time()) - start_time
@@ -1893,6 +1903,69 @@ generate_chat_completions = chat_completion
 generate_chat_completion = chat_completion
 
 
+##################################
+#
+# Anthropic Messages API Compatible Endpoint
+#
+##################################
+
+
+from open_webui.utils.anthropic import (
+    convert_anthropic_to_openai_payload,
+    convert_openai_to_anthropic_response,
+    openai_stream_to_anthropic_stream,
+)
+
+
+@app.post("/api/message")
+@app.post("/api/v1/messages")  # Anthropic Messages API compatible endpoint
+async def generate_messages(
+    request: Request,
+    form_data: dict,
+    user=Depends(get_verified_user),
+):
+    """
+    Anthropic Messages API compatible endpoint.
+
+    Accepts the Anthropic Messages API format, converts internally to OpenAI
+    Chat Completions format, routes through the existing chat completion
+    pipeline, then converts the response back to Anthropic Messages format.
+
+    Supports both streaming and non-streaming requests.
+    All models configured in Open WebUI are accessible via this endpoint.
+
+    Authentication: Supports both standard Authorization header and
+    Anthropic's x-api-key header (via middleware translation).
+    """
+    # Convert Anthropic payload to OpenAI format
+    requested_model = form_data.get("model", "")
+
+    openai_payload = convert_anthropic_to_openai_payload(form_data)
+
+    # Route through the existing chat_completion handler
+    response = await chat_completion(request, openai_payload, user)
+
+    # Convert response back to Anthropic format
+    if isinstance(response, StreamingResponse):
+        # Streaming response: wrap the generator to convert SSE format
+        return StreamingResponse(
+            openai_stream_to_anthropic_stream(
+                response.body_iterator, model=requested_model
+            ),
+            media_type="text/event-stream",
+            headers={
+                "Cache-Control": "no-cache",
+                "Connection": "keep-alive",
+            },
+        )
+    elif isinstance(response, dict):
+        return convert_openai_to_anthropic_response(response, model=requested_model)
+    else:
+        # Passthrough for error responses (JSONResponse, PlainTextResponse, etc.)
+        return response
+
+
+
 @app.post("/api/chat/completed")
 async def chat_completed(
     request: Request, form_data: dict, user=Depends(get_verified_user)