Twilio使用Node.js接收和回复SMS

Question

Im trying to set up our twilio app to respond to a client when it receives an sms. I have created a js file that sends out an initial text and another js file that will send the response when it receives a reply.

I then launched the initial server from my machine then launched ngrok http 1337 I copied and pasted the forwarding url from ngrok into the messaging webhook on my twilio dashboard and added the "/sms" to the end of the url.

When i reply to the text i do not get a response and can see in ngrok that i received a "502 Bad Gateway error".

const accounSid = 'xxxxxxxxxxxxx'
const authToken = 'xxxxxxxxxxxxx'

const client  = require('twilio')(accounSid, authToken)

client.messages.create({
    to: '+13101234567',
    from: '+13109876543',
    body: 'test'
})
.then((message) => {
    console.log(message.sid)
})

---

const http = require('http')
const express = require('express')

const MessagingResponse = require('twilio').twiml.MessagingResponse

const app = express()

app.post('/sms', (req,res) => {
    const twiml = new MessagingResponse()

    twiml.message('testing 123')

    res.writeHead(200, {'Content-Type': 'text/xml'})
    res.end(twiml.toString())
})

http.createServer(app).listen(1337, () => {
    console.log('express server listening on port 1337')
})

Answer 1

You get 502 Bad Gateway from ngrok because your Express http server is not working or is something wrong with it.

When you respond to SMS, Twilio is making a POST request to your ngrok and that is working because you get that message 502 Bad Gateway on screen.

When you launch Express you should see express server listening on port 1337

If you go with your browser to http://localhost:1337/ you should see a page with Cannot GET / since the browser does not make a POST request, but at least you can confirm that the Express server is working.