NodeJS MQTT minimal subscribe example with JSON messages

const mqtt = require('mqtt')
const client = mqtt.connect('mqtt://user:[email protected]')

client.on('connect', () => {
  client.subscribe('mytopic');
})

client.on('message', (topic, message) => {
  console.log(topic, JSON.parse(message))
})

If required, you can install the mqtt library using

npm i --save mqtt