Update app.py

app.py

@@ -9,6 +9,7 @@ from langchain_core.documents import Document
 from langgraph.graph import END, StateGraph
 from typing_extensions import TypedDict, Annotated
 from typing import Sequence, Dict, List, Optional, Any
+from langgraph.graph.message import add_messages  # Add this import
 import chromadb
 from chromadb.config import Settings
 import numpy as np