Javascript訂閱、發佈MQTT訊息則是使用MQTT.js。
安裝

npm install mqtt --save

發佈

var mqtt = require('mqtt')
var client  = mqtt.connect('mqtt://127.0.0.1:1883')
 
client.on('connect', function () {
  client.publish('temperature/Wuling', '23.4');
  client.end();
})

訂閱

var mqtt = require('mqtt')
var client  = mqtt.connect('mqtt://127.0.0.1:1883')
 
client.on('connect', function () {
  client.subscribe('temperature/Wuling', function (err) {

  })
})
 
client.on('message', function (topic, message) {
  // message is Buffer
  console.log(message.toString())
})