Update app.py

app.py

@@ -6,6 +6,7 @@ from typing import TypedDict, Annotated, Sequence
 import operator
 from langchain_core.messages import BaseMessage, HumanMessage, ToolMessage
 from langchain.tools import tool
+from langchain_community.tools.tavily_search import TavilySearchResults
 from langchain_openai import ChatOpenAI
 from langgraph.graph import StateGraph, END
 from langgraph.prebuilt import ToolNode, tools_condition