mqtt.js

Important note for existing users

v0.2.0 has brough some API breaking changes to mqtt.js. Please consult the migration guide for information or open an issue if you need any help.

Introduction

mqtt.js is a library for the MQTT protocol, written in javascript.

Installation

npm install mqtt

Documentation

Detailed documentation can be found in the wiki

Client API usage

A basic publish client, the basis for bin/mqtt_pub:

var mqtt = require('mqtt');
var argv = process.argv;

for (var i = 2; i <= 5; i++) {
  if(!argv[i]) process.exit(-1);
}

var port = argv[2],
  host = argv[3],
  topic = argv[4],
  payload = argv[5];

var client = mqtt.createClient(port, host)
client.on('connect', function() {
  client.publish(topic, payload);
  client.end();
});

Server API usage

A broadcast server example, included in examples/broadcast.js:

var mqtt = require('mqtt');

mqtt.createServer(function(client) {
  var self = this;

  if (!self.clients) self.clients = {};

  client.on('connect', function(packet) {
    client.connack({returnCode: 0});
    client.id = packet.client;
    self.clients[client.id] = client;
  });

  client.on('publish', function(packet) {
    for (var k in self.clients) {
      self.clients[k].publish({topic: packet.topic, payload: packet.payload});
    }
  });

  client.on('subscribe', function(packet) {
    var granted = [];
    for (var i = 0; i < packet.subscriptions.length; i++) {
      granted.push(packet.subscriptions[i].qos);
    }

    client.suback({granted: granted});
  });

  client.on('pingreq', function(packet) {
    client.pingresp();
  });

  client.on('disconnect', function(packet) {
    client.stream.end();
  });

  client.on('close', function(err) {
    delete self.clients[client.id];
  });

  client.on('error', function(err) {
    client.stream.end();
    console.log('error!');
  });
}).listen(1883);