create-phone-number-forwarding (CPNF)

A small CLI utility that buys a Twilio number and forwards incoming calls/SMS' to your own number

Prerequisite

To buy and configure phone numbers using CPNF you need to have a free Twilio account and a UNIX environment.

⚠️ Running this script will create cost because it buys a US Twilio phone number. If you want to have more information have a look at the pricing page.

Okay, but what's Twilio?

Twilio is a global cloud communications and customer engagement platform that has several APIs at it's core. These APIs enable developers to build and automate flows that usually happen over phone, SMS, Whatsapp, Email, ...

Setup

Make sure you have the following configuration values at hand (or stored in environment variables):

• your Twilio account SID (TWILIO_ACCOUNT_SID)
• your Twilio auth token (TWILIO_AUTH_TOKEN)
• the phone number you want redirect calls and SMS to (MY_PHONE_NUMBER)

CPNF will ask for these values if they were not present in the environment variables.

npx run create-phone-number-forwarding

# or alternatively

npm i -g create-phone-number-forwarding
create-phone-number-forwarding

That's it to buy and configure a phone number. And it should like the following: 👇

Cool, but how does this work?

Whenever someone calls or sends a text message to a Twilio phone number, Twilio will make an HTTP request (a so called webhook) to a configurable URL. This URL should return TwiML (Twilio's configuration file format).

To forward SMS and phone call what you need to publicly accessible URLs that return the following configuration

TwiML configuration to forward a call

<Response>
  <Dial>$YOUR_PHONE_NUMBER</Dial>
</Response>

TwiML configuration to forward an SMS

<Response>
  <Message to="$YOUR_PHONE_NUMBER">From: $SENDER. Message: $MESSAGE_BODY</Message>
</Response>

Webhook URLs via Twilio functions

Luckily, Twilio offers also a serverless product. These let you deploy quick HTTP endpoints in a few minutes.

Function to foward a call

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

Function to forward an SMS

exports.handler = function(context, event, callback) {
  let twiml = new Twilio.twiml.MessagingResponse();
  twiml.message(`From: ${event.From}. Message: ${event.Body}`, {
    to: context.MY_PHONE_NUMBER
  });
  callback(null, twiml);
};

CPNF sits on top of twilio-run and the Twilio CLI. All the logic and functionality can be found in create-phone-number-forwarding.sh.

Celebrate result 🎉

Phone calls and SMS to your new Twilio number will now be forwarded to your personal number.