Twilio Machine Detection AnsweredBy field returns 'None'

Question

I'm developing a Twilio app that leverages the Machine Detection features. I make a request using the Twilio python client as follows:

import twilio
twilio_client = Client(ACCOUNT_SID, AUTH_TOKEN)

call = twilio_client.calls.create(
        to=number,
        from_=TWILIO_PHONE_NUMBER,
        url=EXTERNAL_URL + '/call',
        status_callback=EXTERNAL_URL + '/call_status',
        status_callback_event=["initiated", "ringing", "answered",
                               "completed", "no-answer", "busy",
                               "failed", "canceled", "queued"],
        machine_detection='Enable',
        machine_detection_timeout=20,
    )

but when I try to access the call.answered_by field I discover that the value is None. I also get back None when I use the call status API to fetch the call status 10 seconds later:

call = twilio_client.calls(sid).fetch()

Also in my my webhook that I register at `EXTERNAL_URL + '/call_status' to get notifications I don't get an 'AnsweredBy' field. I've also made sure I enabled the feature in the Twilio web console. What else I am missing?

Answer 1

Twilio developer evangelist here.

Thanks to Andy and Alex in the comments, I think they actually do cover everything.

The key here is that the AnsweredBy field will be sent as part of the webhook to the URL you set as the url parameter in the API request. In this case, that is the URL EXTERNAL_URL + '/call'.

The AnsweredBy field should eventually appear in the REST API for the call resource itself, but the way to use it is via the webhook.

Let me know if this helps at all.