feat: set memory in chain

app.py

@@ -37,19 +37,20 @@ def initialize_session_state():
             model="text-davinci-003",
         )
 
-        st.session_state.memory = ConversationBufferMemory()
+        memory = ConversationBufferMemory(
+            memory_key="chat_history", return_messages=True
+        )
         st.session_state.conversation = ConversationalRetrievalChain.from_llm(
-            llm=llm, retriever=retriever, verbose=True
+            llm=llm, retriever=retriever, verbose=True, memory=memory
         )
 
 
 def on_click_callback():
     with get_openai_callback() as cb:
         human_prompt = st.session_state.human_prompt
-        llm_response = st.session_state.conversation.run(
+        llm_response = st.session_state.conversation(
             {
                 "question": human_prompt,
-                "chat_history": st.session_state.memory.buffer,
             }
         )
         st.session_state.history.append(Message("human", human_prompt))