Capturing Twilio's outgoing call status on google appscript - flask

Question

I am trying to get the status of my outgoing twilio calls and update them onto the spreadsheet. "Completed, Busy, No-Answer, Cancelled, Failed".
However, I do not know where to include the StatusCallBackEvent and how to access the retrieved status from Google Apps Script.
Here is the code which I have to initiate an outbound call.
function makeCall(to) {
var call_url = "https://api.twilio.com/2010-04-01/Accounts/" + TWILIO_ACCOUNT_SID + "/Calls.json";
var payload = {
"To": "+" + String(to),
"From" : TWILIO_NUMBER,
"Url": "http://a1fb888ec032.ngrok.io/" +"voice",
"Method": "GET"
};
var options = {
"method" : "post",
"payload" : payload
};
options.headers = {
"Authorization" : "Basic " + Utilities.base64Encode(TWILIO_ACCOUNT_SID + ":" + TWILIO_AUTH_TOKEN)
};
var response = UrlFetchApp.fetch(call_url, options);
UrlFetchApp.fetch(call_url, options);
return JSON.parse(response);
}

Answer 1

Twilio developer evangelist here.
To receive the status of the call, you need to set a StatusCallback URL when you create the call. The URL should point towards a URL which you control that can update your spreadsheet when it receives an HTTP request from Twilio.
var payload = {
"To": "+" + String(to),
"From" : TWILIO_NUMBER,
"Url": "http://a1fb888ec032.ngrok.io/" +"voice",
"Method": "GET",
"StatusCallback": "https://SOME_URL"
};
You can use Google Sheets and App Script to set up a web application that can receive webhooks like this. Briefly, you need to create script that has a doPost method (Twilio webhooks are POST requests by defaults) and returns a successful response. Twilio statusCallback webhooks don't expect any content in the response, so you can use an empty text output.
Something like this might work:
function doPost(event) {
var callSid = event.parameter("CallSid");
var status = event.parameter("CallStatus");
// update spreadsheet with call status
return ContentService.createTextOutput('');
}
Check out the documentation on turning scripts into web apps and Twilio call status callbacks for more details.