Update app.py

app.py

@@ -164,7 +164,7 @@ async def handle_message(message: cl.Message):
 
         response = await post_tool.ainvoke(
             json.dumps(post_data),
-            config={"callbacks": [cl.AsyncLangchainCallbackHandler()]
+            config={"callbacks": [cl.AsyncLangchainCallbackHandler()]}
         )
                
     else: