Getting error 11200 on every sms message that posts to slack - sms

Question

im trying to send sms message to slack, i have it where the message is posted. the problem im having is that the twilio console gives a 11200 error on every message.
/**
* Dependencies:
* Dotenv, Express, BodyParser, Slack Web Client, Slack Events API
*/
require('dotenv').config();
const express = require('express');
const bodyParser = require('body-parser');
const createSlackEventAdapter = require('#slack/events-api').createSlackEventAdapter;
//a new export, ErrorCode, is a dictionary of known error types
const { WebClient } = require('#slack/client');
const twilio = require('twilio');
const firebase = require('firebase');
// Creates our express app
const app = express();
// The channel we'll send TalkBot messages to
const channel = 'CBY5883L3';
// The port we'll be using for our Express server
const PORT = 3000;
// Use BodyParser for app
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json());
/**
* Tokens:
* Slack, Firebase, Twilio
*/
//Retrieve bot token from dotenv file
const bot_token = process.env.SLACK_BOT_TOKEN || '';
// Authorization token
const auth_token = process.env.SLACK_AUTH_TOKEN || '';
// Verification token for Events Adapter
const slackEvents = createSlackEventAdapter(process.env.SLACK_VERIFICATION_TOKEN);
//Slack web client
const web = new WebClient(auth_token);
const bot = new WebClient(bot_token);
//Twilio tokens
const twilio_sid = process.env.TWILIO_SID || '';
const twilio_auth = process.env.TWILIO_AUTH_TOKEN || '';
// Initialize Twilio client using our Twilio SID and Authorization token
const twilioClient = twilio(twilio_sid, twilio_auth);
app.listen(PORT, function (err) {
if (err) {
throw err
}
console.log('Server started on port 3000')
})
// Handles incoming SMS to Twilio number
app.post('/sms', function (req, res) {
const body = req.body.Body
const num = req.body.From
// Sends message to Slack - in format from {
// `res` contains information about the posted message
console.log('Message sent: ', res.ts);
})
.catch(console.error);
}

Answer 1

You get this error
Error - 11200 HTTP retrieval failure
because Twilio expects a response as it makes the POST request to your /sms endpoint.
The response needs to be a valid TwiML (XML).
Change your code:
// Handles incoming SMS to Twilio number
app.post('/sms', function (req, res) {
const body = req.body.Body
const num = req.body.From
// Sends message to Slack - in format from {
// `res` contains information about the posted message
console.log('Message sent: ', res.ts);
})
.catch(console.error);
}
to this:
// Handles incoming SMS to Twilio number
app.post('/sms', function (req, res) {
const body = req.body.Body
const num = req.body.From
// Sends message to Slack - in format from {
// `res` contains information about the posted message
const twiml = new twilio.twiml.MessagingResponse();
twiml.message('Your SMS was forwarded to Slack...');
res.writeHead(200, { 'Content-Type': 'text/xml' });
res.end(twiml.toString());
});
If don't want to respond to the sender then you just comment out this line
// twiml.message('Your SMS was forwarded to Slack...');
I hope this helps.