Make Outbound Phone Calls with Node.js

Purchase a voice-enabled Twilio phone number

In the Twilio console, search for and purchase an available phone number capable of making outbound calls. You'll use this phone number as the "From" phone number when you initiate an outbound call.

Retrieve your Twilio account credentials

First, you'll need to get your Twilio account credentials. They consist of your AccountSid and your Auth Token. They can be found on the home page of the console.

There are a few key parameters to drill into when making the outbound call.

• "From" - the voice-enabled Twilio phone number you added to your account earlier
• "To" - the person you'd like to call
• "Twiml" - Instructions in the form TwiML that explains what should happen when the other party picks up the phone
• "Url" - Optionally, instead of passing the Twiml parameter, you can provide a Url that returns TwiML Voice instructions.

What is TwiML?

TwiML is the Twilio Markup Language, which is just to say that it's an XML document with special tags defined by Twilio to help you build your SMS and voice applications. TwiML is easier shown than explained. Here's some TwiML you might use to respond to an incoming phone call:

And here's some TwiML you might use to respond to an incoming SMS message:

Every TwiML document will have the root <Response> element and within that can contain one or more verbs. Verbs are actions you'd like Twilio to take, such as <Say> a greeting to a caller, or send an SMS <Message> in reply to an incoming message. For a full reference on everything you can do with TwiML, refer to our TwiML API Reference.