Update app/main.py

app/main.py

@@ -86,6 +86,11 @@ async def rag_stream(request: Request, db: Session = Depends(get_db)):
         question=user_request.question,
         chat_history=format_chat_history(chat_history),
     )
+
+    stream = rag_chain.stream(
+        rag_input.dict(),
+        config={"callbacks": [Callback()]}
+    )
     callback = LogResponseCallback(user_request, db)
     return EventSourceResponse(generate_stream(rag_input, callback))