anjz/MQTT.js

An MQTT library for node.js

mqtt.js

Introduction

mqtt.js is a library for the MQTT protocol, written in JavaScript to be used in node.js.

Important notes for existing users

• v0.3.0 improves connection stability, performance, the reconnection logic and SSL support. See #118 for details. A Connection is a Writable stream, so you can run MQTT.js over any kind of Stream (doc needed). Both the constructors of MqttClient and MqttConnection changed, but not the factory method mqtt.createClient and mqtt.createConnection.

• 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.

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

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, messageId: packet.messageId});
  });

  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);