Twilio function - exports event object undefined

Question

I have a Twilio function, as below; it forwards the SMS to an email address. In the phone number's configuration, I am calling this function when 'A message comes in'. There is no other component involved - no callback, no Messaging Service, no Studio, nada.

const got = require('got');
exports.handler = function(context, event, callback) {
    console.log(event.to);

    const requestBody = {
        subject: `sms to [${event.to}, from ${event.From}`, 
        //build rest of JSON request
    }
    
    got.post('https://api.mailclient.com/v3/mail/send', {
        headers: {
          'Authorization': `Bearer ${context.DEV__API_TOKEN}`,
          'Content-Type': 'application/json'
        },
        body: JSON.stringify(requestBody)
    })
    .then(response => {
          let twiml = new Twilio.twiml.MessagingResponse();
          callback(null, twiml);
   })
   .catch(err => {
        console.error(err);
        callback(err, 'error');
   });

};

I am testing the setup by sending an SMS from a mobile phone. Of course the email goes through, but the ${event.to} always turns up as 'undefined'. I am not sure what am I missing. Any pointers, please?

Answer 1

Twilio developer evangelist here.

In the incoming request the parameters are all capitalised values. You are already correctly using event.From, so you just need to change event.to to event.To and it will no longer be undefined.