Update app.py

app.py

@@ -52,13 +52,7 @@ chat_prompt = ChatPromptTemplate.from_messages([
 
 chat_model = ChatOpenAI(model="gpt-4o-mini")
 set_llm_cache(InMemoryCache())
-
-retrieval_augmented_qa_chain = (
-        {"context": itemgetter("question") | retriever, "question": itemgetter("question")}
-        | RunnablePassthrough.assign(context=itemgetter("context"))
-        | chat_prompt | chat_model
-    )
-
+chat_openai = ChatOpenAI()
 
 ### On Chat Start (Session Start) Section ###
 @cl.on_chat_start
@@ -114,18 +108,17 @@ async def on_chat_start():
     vectorstore.add_documents(docs)
     retriever = vectorstore.as_retriever(search_type="mmr", search_kwargs={"k": 3})
     
-    chat_openai = ChatOpenAI()
-
     # Create a chain
-    retrieval_augmented_qa_pipeline = RetrievalAugmentedQAPipeline(
-        vector_db_retriever=vector_db,
-        llm=chat_openai
+    retrieval_augmented_qa_chain = (
+        {"context": itemgetter("question") | retriever, "question": itemgetter("question")}
+        | RunnablePassthrough.assign(context=itemgetter("context"))
+        | chat_prompt | chat_model
     )
     
     # Let the user know that the system is ready
     msg.content = f"Processing `{file.name}` done. You can now ask questions!"
     await msg.update()
-    cl.user_session.set("chain", retrieval_augmented_qa_pipeline)
+    cl.user_session.set("chain", retrieval_augmented_qa_chain)
 
 
 ### Rename Chains ###