Twilio TwiML Bins Restriction - twilio

Question

I am trying to use Twilio to create a conference call where it will be recorded. The idea is that I will merge my call with my Twilio number and it will start recording. However, I was wondering if it was possible to add restrictions.
So recording will turn on if certain numbers are on the phone, which I can add or delete.
Below is my working code that can record any calls regardless of their number.
<?xml version="1.0" encoding="UTF-8"?>
<Response>
<Say>Your call is being recorded</Say>
<Dial record="record-from-answer-dual" trim="trim-silence">
<Conference waitUrl="">
Conference Room
</Conference>
</Dial>
</Response>

Answer 1

TwiML Bins are great but sometimes, they wont work since you need to implement conditional logic to make things happen.
Twilio has a product called Twilio Functions, which is in Beta, which allows you to implement conditional logic and not have to spin up your own web servers to host that logic. Sort of like TwiML bins on steroids.
You can tweak the code below, to meet you needs. It nearly does what you want but use it more as an example of what you can do, and work from there. It is written in Javascript/Node.js. You would just need to update the logic to include TwiML which records the conference - https://www.twilio.com/docs/voice/twiml/conference#record.
You would then do the follow.
Go to Twilio Functions in your browser - https://www.twilio.com/console/runtime/functions/manage
Click the Red "+"
click + Blank for a Blank Template and click Create
Give the Function a Friendly Name, like ConferenceConditionalRecord or something similar you like
Give the Function a path, for example /conference
Erase the code in the Code box and cut/paste the code below, customizing it to meet your needs and click save
Visit you incoming numbers, https://www.twilio.com/console/phone-numbers/incoming
Choose Your Twilio Number
Under Voice & Fax, A Call Comes In, choose Function and then your Function and click Save
Test it out by calling in from different numbers. Only the 3 below will start the conference.
exports.handler = function(context, event, callback) {
let twiml = new Twilio.twiml.VoiceResponse();
let callerId = event.From || null;
let conferenceParams = {};
let conferenceName = "My Example Conference Room";
let moderators = ["[phone]", "[phone]", "[phone]"];
conferenceParams.beep = true;
if (moderators.indexOf(callerId) === -1) {
conferenceParams.startConferenceOnEnter = false;
conferenceParams.endConferenceOnExit = false;
}
else
{
conferenceParams.startConferenceOnEnter = true;
conferenceParams.endConferenceOnExit = true;
}
twiml.dial().conference(conferenceParams, conferenceName);
callback(null, twiml);
};