Use the MQTT.js library with Node.js or in the browser to publish and subscribe using MQTT.
// require npm package
const mqtt = require('mqtt');
// declare client
const client = mqtt.connect('mqtt://public:public@public.cloud.shiftr.io', {
clientId: 'javascript'
});
// register "connect" callback
client.on('connect', function() {
console.log('connected!');
// subscribe to topic
client.subscribe('hello');
// publish message every second
setInterval(function() {
client.publish('hello', 'world');
}, 1000);
});
// register "message" callback
client.on('message', function(topic, message) {
console.log(topic + ': ' + message.toString());
});
For more information see the JavaScript manual in the documentation.