Added middleware

Added an endpoint for invoking a response directly, circumventing the add_routes langserve method, to identify where the issue lies while deploying.

Result: Got the same error message regardless of using langserve or not, so added back in but kept the middleware.

feide_docs_rag/app.py

@@ -3,7 +3,8 @@ import asyncio
 
 from fastapi import FastAPI, HTTPException
 from pydantic import BaseModel
-from langserve import add_routes
+# from langserve import add_routes
+from fastapi.middleware.cors import CORSMiddleware
 
 if sys.platform == "win32":
     asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
@@ -16,6 +17,16 @@ app = FastAPI(
     description="Spin up a simple api server using Langchain's Runnable interfaces",
 )
 
+# Set all CORS enabled origins
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+    expose_headers=["*"],
+)
+
 class InvokeRequest(BaseModel):
     question: str
     chat_history: list[str]