Integrate Twilio with Firebase Cloud Functions

index.js

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);


const twilio = require('twilio');
const accountSid = functions.config().twilio.sid
const authToken  = functions.config().twilio.token

const client = new twilio(accountSid, authToken);

const twilioNumber = '+19168274107' // your twilio phone number


exports.textStatus = functions.database
       .ref('/orders/{orderKey}/status')
       .onUpdate(event => {


    const orderKey = event.params.orderKey

    console.log(event)


    return admin.database()
                .ref(`/orders/${orderKey}`)
                .once('value')
                .then(snapshot => snapshot.val())
                .then(order => {
                    const status      = order.status
                    const phoneNumber = order.phoneNumber

                    if ( !validE164(phoneNumber) ) {
                        throw new Error('number must be E164 format!')
                    }

                    const textMessage = {
                        body: `Current order status: ${status}`,
                        to: phoneNumber,  // Text to this number
                        from: twilioNumber // From a valid Twilio number
                    }

                    return client.messages.create(textMessage)
                })
                .then(message => console.log(message.sid, 'success'))
                .catch(err => console.log(err))


});


/// Validate E164 format
function validE164(num) {
    return /^\+?[1-9]\d{1,14}$/.test(num)
}

it wont work without billing set up, so yes you need either Flame or Blaze plan. the reason is that cloud functions in their free usage has lots of latency and is very restricted. if you try this with a free version, look in the functions call logs and you will see this explanation

Thanks for revert