W4 D1 HW

app.py

@@ -128,7 +128,10 @@ async def start_chat():
     The user session is a dictionary that is unique to each user session, and is stored in the memory of the server.
     """
 
-    lcel_rag_chain = rag_prompt | hf_llm
+    lcel_rag_chain = ( {"context": itemgetter("query") | hf_retriever, "query": itemgetter("query")}
+                      
+                       | rag_prompt | hf_llm
+                    )
 
     cl.user_session.set("lcel_rag_chain", lcel_rag_chain)