Update app.py

app.py

@@ -6,6 +6,7 @@ import pandas as pd
 from typing import TypedDict, Optional, Annotated
 from langchain_core.messages import AnyMessage
 from langchain_huggingface import HuggingFaceEndpoint, ChatHuggingFace
+from langgraph.graph.message import add_messages
 
 
 class State(TypedDict):