Update app.py

app.py

@@ -46,7 +46,7 @@ class BasicAgent:
         # Assistant function (process one step)
         def assistant(state: AgentState):
             return {
-                "messages": [chat_with_tools.invoke(state["messages"])]
+                "messages": [chat.invoke(state["messages"])]
             }
 
         # Create a StateGraph