Voice mail system using Twilio Functions

1-start.js

exports.handler = function(context, event, callback) {
  let twiml = new Twilio.twiml.VoiceResponse();
  const OWNER = '+1##########'; //Your mobile number.
  
  if(event.From == OWNER){
    const gather = twiml.gather({
      action:'/callOut'
    });
    
  gather.say("Please enter the phone number you'd like to call followed by the pound sign.");
    
} else {
  twiml.sms({from:'+1##########', to:'+1##########'}, `You received a call from ${event.From}.`); //from = Twilio phone number. to = your mobile number.
  
  dial = twiml.dial({
    callerId:'+1##########', //Your Twilio phone number.
    action:'/vmail'
  });
  
  dial.number({
    url:'/whisper'
  }, OWNER);
}
  
callback(null, twiml);
};

callOut.js

exports.handler = function(context, event, callback) {
  let twiml = new Twilio.twiml.VoiceResponse();
  dial = twiml.dial({
    callerId:'+1##########' //Your Twilio number.
  });
  dial.number("+"+event.Digits);
  callback(null, twiml);
};

empty-response.xml

<?xml version="1.0" encoding="UTF-8"?>
<Response />

gather-results.js

exports.handler = function(context, event, callback) {
  let twiml = new Twilio.twiml.VoiceResponse();

  if(event.Digits && event.Digits === null ){
    twiml.hangup();
  } else {
    twiml.say("Your call is now being connected.");
  }
  
callback(null, twiml);
};

vmail.js

exports.handler = function(context, event, callback) {
  let twiml = new Twilio.twiml.VoiceResponse();

  if (event.DialCallStatus === "completed" || event.DialCallStatus === "answered") {
    twiml.hangup();
  }

  //Change this to reflect your own personal message.
  twiml.say("You have reached my voice mail. Please leave a message.");

  //Or use play to play a recorded message
  //twiml.play("https://your-url.io/voicemail.mp3");

  twiml.record({
    action: "empty-response.xml", //Use a link to a TwiML Bin for this value.
    method: "GET",
    maxLength: "200",
    recordingStatusCallback: "/vmlink"
  });

  twiml.sms({from:'+1##########', to:'+1##########'}, `The last caller did not leave a VMail.`);

  callback(null, twiml);
};

vmlink.js

exports.handler = function(context, event, callback) {
  
  if (event.RecordingStatus && event.RecordingStatus === 'completed' && event.RecordingDuration > 3){
    context.getTwilioClient().messages.create({
      to: '+1##########', //Your mobile number.
      from: '+1##########', //Your Twilio number.
      body: `The previous missed call left you a voice mail. Duration: ${event.RecordingDuration} secs. Tap the link to listen: ${event.RecordingUrl}.mp3`})
        .then(msg => {
          callback(null, msg.sid);
        }).catch(err => callback(err));
  } else {
    context.getTwilioClient().messages.create({
      to: '+1##########', //Your mobile number.
      from: '+1##########', //Your Twilio number.
      body: `The last caller did not leave a VMail.`}).then(msg => {
        callback(null, msg.sid);
      }).catch(err => callback(err));
    }
};

whisper.js

exports.handler = function(context, event, callback) {
  let twiml = new Twilio.twiml.VoiceResponse();
  let gather = twiml.gather({
    action: "/gather-results",
    numDigits: "1",
    timeout: "10"
  });
  gather.say({loop:"2"}, 'You have an incoming call. Press any number key to accept the call, or hang up to send the caller to voice mail.');
  twiml.hangup();
  callback(null, twiml);
};