Error using callbacks on RetrievalQAWithSourcesChain

[tomatefarcie123]

I get TypeError: 'tuple' object is not callable running this code. I guess it's because a run call doesn't work on a chain with multiple outputs,

How then can I use callbacks on that chain?

from flask import Flask, render_template from flask_socketio import SocketIO from initialize_llm_chain import build_chain from langchain.callbacks.base import BaseCallbackHandler

Create a custom handler to stream llm response

class StreamingHandler(BaseCallbackHandler): def on_llm_new_token(self, token: str, **kwargs) -> None: socketio.emit('new_token', token)

def catch_all(*args, **kwargs):
    pass

on_agent_action = on_agent_finish = on_chain_end = on_chain_error = on_chain_start = on_llm_end = on_llm_error = on_llm_start = on_text = on_tool_end = on_tool_error = on_tool_start = catch_all

Build the langchain chain

qa_chain = build_chain()

Instantiate the handler

handler = StreamingHandler()

Initialize flask app

app = Flask(name) socketio = SocketIO(app)

Define source route

@app.route('/') def index(): return render_template('index.html')

Define socket query

@socketio.on('query', namespace='/results') def handle_query(data): results = qa_chain(data, callbacks=[handler]) ('results', results["answer"])

if name == 'main': socketio.run(app, host='localhost', port=9000, debug=True)