Twilio Studio & Functions - Call Whispers - twilio

Question

I'm trying to implement a simple call whisper that lets our agent know which phone number/product has been dialed. When a call comes in, it goes through a studio flow where the caller chooses a language. The call is then routed to a taskrouter queue via the "Enqueue" widget. From what I've read in the documentation, I need to pass the callback function a instruction: 'call' parameter in order to be able to specify a URL to be "played" to the agent.
I'm currently limited to implementing everything inside of twilio itself via Studio and Functions.
Why isn't this working, and what specifically do I need to do?
Thanks!
Assignment Callback Function
exports.handler = function(context, event, callback) {
const client = context.getTwilioClient();
let eventInfo = JSON.parse(event.TaskAttributes);
// const response = new Twilio.twiml.VoiceResponse();
console.log(Object.keys(event));
console.log(JSON.parse(event.TaskAttributes));
console.log(Object.keys(JSON.parse(event.TaskAttributes)));
// console.log(JSON.parse(event.WorkerAttributes));
const worker = JSON.parse(event.WorkerAttributes);
// console.log("ReservationSid: " + event.ReservationSid);
// console.log(typeof eventInfo);
// // ATTEMPT 1
// // This works to dequeue a call to a worker, but there is no whisper functionality
// callback(null, {
// 'instruction':'dequeue',
// 'post_work_activity_sid' : 'WORKSPACEACTIVITYSID',
// 'from' : eventInfo.from
// });
// // ATTEMPT 2
// // This works to play the whisper to the agent, but the caller is never connected to the agent.
let callbackURL = 'TWILIOFUNCTIONURL';
callback(null, {
'instruction':'call',
'post_work_activity_sid' : 'WORKSPACEACTIVITYSID',
'from' : eventInfo.from,
'url' : callbackURL
});
// // ATTEMPT 3 - Building a twiml version of attempt #2
// // This doesn't work.
//
// let callbackURL = 'TWILIOFUNCTIONURL';
// let twiml = new Twilio.twiml.VoiceResponse();
// const dial = twiml.dial();
// dial.queue({
// 'instruction':'call',
// // 'post_work_activity_sid' : 'WORKSPACEACTIVITYSID',
// 'from' : eventInfo.from,
// 'accept' : true,
// 'url' : callbackURL,
// // 'reservationSid' : event.ReservationSid
// }, event.selected_language);
// console.log(dial.toString());
// console.log(twiml.toString());
// callback(null, twiml);
// // ATTEMPT 4 - Build a twiml version of attempt #1
// // This doesn't work.
//
// let twiml = new Twilio.twiml.VoiceResponse();
// twiml.dial({
// 'instruction':'dequeue',
// 'post_work_activity_sid' : 'WORKSPACEACTIVITYSID',
// 'from' : eventInfo.from
// // 'to' : 'WORKSPACEQUEUESID'
// });
// console.log(twiml.toString());
// callback(null, twiml);
};
Callback URL containing queue announcement stuff.
exports.handler = function(context, event, callback) {
let twiml = new Twilio.twiml.VoiceResponse();
// let client = context.getTwilioClient();
// console.log("BEGIN Queue Announcer - context");
// console.log(Object.keys(context));
// console.log(context);
// console.log("BEGIN Queue Announcer - event");
// console.log(Object.keys(event));
// console.log(event);
// console.log("BEGIN Queue Announcer - client");
// console.log(Object.keys(client));
// console.log(client);
// console.log("END Queue Announcer");
// Random attempt to get the call info
// console.log("BEGIN Queue Announcer - CallSid");
// console.log(event.CallSid);
// client.calls(event.CallSid)
// .fetch()
// .then(call => console.log("Call: " + call));
// console.log("END Queue Announcer - CallSid");
let client = context.getTwilioClient();
twiml.say("QUEUE NAME GOES HERE");
twiml.dial()
.queue({
// 'reservationSid' : event.ReservationSid
}, 'english');
callback(null, twiml);
};

Answer 1

Here's what I did that worked. This is contained within a function that is effectively the "assignment callback URL".
Steps:
Use the 'echo' twimlet to generate the twiml. Modify the supplied URL to include the 'event.RegistrationSid' where appropriate.
Accept the registration via a POST request.
Do the callback, including the 'instruction : call' parameter.
exports.handler = function(context, event, callback) {
const client = context.getTwilioClient();
let eventInfo = JSON.parse(event.TaskAttributes);
// Generate the callback url
let callbackURL = `http://twimlets.com/echo?Twiml=%3C%3Fxml%20version%3D%221.0%22%20encoding%3D%22UTF-8%22%3F%3E%0A%3CResponse%3E%0A%3CSay%3ECALLWHISPERGOESHERE%3C%2FSay%3E%0A%3CDial%3E%0A%3CQueue%20reservationSid%3D%22${event.ReservationSid}%22%3E%3C%2FQueue%3E%0A%3C%2FDial%3E%0A%3C%2FResponse%3E&`;
// Generate POST request to accept the reservation
const rp = require("request-promise");
const postURI = `https://taskrouter.twilio.com/v1/Workspaces/${event.WorkspaceSid}/Tasks/${event.TaskSid}/Reservations/${event.ReservationSid}`;
const postForm = {
ReservationStatus: "accepted"
};
const postAuth = {
user: context.ACCOUNT_SID,
pass: context.AUTH_TOKEN
};
const options = {
method: "POST",
uri: postURI,
auth: postAuth,
form: postForm
};
rp(options)
.then(body => {
console.log(body);
callback(null, null);
})
.catch(err => {
console.log(err);
callback(null, err);
});
// Call the agent
callback(null, {
instruction: "call",
post_work_activity_sid: "POSTWORKACTIVITYSID",
from: eventInfo.from,
url: callbackURL
});
};