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

See: examples/client

Simple publish client:

var mqtt = require('mqtt')
  , client = mqtt.createClient();

client.publish('messages', 'mqtt');
client.publish('messages', 'is pretty cool');
client.publish('messages', 'remember that!', {retain: true});
client.end();

Simple subscribe client:

var mqtt = require('mqtt')
  , client = mqtt.createClient();

client.subscribe('messages');
client.publish('messages', 'hello me!');
client.on('message', function(topic, message) {
  console.log(message);
});

Chainable API!:

var mqtt = require('mqtt')
  , client = mqtt.createClient();

client
  .subscribe('messages')
  .publish('presence', 'bin hier')
  .on('message', function(topic, message) {
    console.log(topic);
  });

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.clientId;
    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);