User Interface Toolkits for Node.js
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A user interface toolkit for Node.js, which is based on Qt for rendering. This project can be used to load and play QML file, make it possible to have a easy way to communicate between QML and Node.js for desktop application.


The JavaScript in QML is limited, so Brig

The JavaScript in QML is limited, which is used for QML components control only. If developer need more functions that something's like system calls(FileSystem, Socket, crypto ...etc) or using external libraries, C/C++ is the only way to make it.

In order to make QML application in pure JavaScript possible, Brig provides a way to use Node.js to extends QML without C/C++. That means developer can do more thing in QML with NPM modules and Node.js APIs.


Ensure Qt 5+ tookits and Node.js 0.10+ are ready to go on your system.

For MacOSX user, no need to install Qt development environment for brig anymore. :-)

Known Issues

  • Failed to build brig for Qt 5.8+


Install module via NPM

npm install brig

Get Started

There is a simple way to go by loading existed QML file, so you can prepare a QML content like below:


import QtQuick 2.3
import QtQuick.Controls 1.0

ApplicationWindow {
	visible: true;
	color: 'black';
	title: 'Brig Demo';
	width: 640;
	height: 480;

	Text {
		anchors.centerIn: parent;
		text: 'Brig'; 'Helvetica';
		font.bold: true;
		font.pointSize: 72;
		color: '#00ffcc';
		scale: 0;
		opacity: 0;

		Text {
			anchors.topMargin: 10; parent.bottom;
			anchors.horizontalCenter: parent.horizontalCenter;
			text: 'QML Application in Node.js'; 'Helvetica';
			font.pointSize: 16;
			color: '#e6fffa';

		Behavior on opacity {
			NumberAnimation {
				duration: 800;
				easing.type: Easing.OutCubic;

		Behavior on scale {
			NumberAnimation {
				duration: 1000;
				easing.type: Easing.OutBack;

		Component.onCompleted: {
			opacity = 1.0;
			scale = 1.0;

Then using Brig to load file in Node.js:

var Brig = require('brig');

var brig = new Brig();

brig.on('ready', function(brig) {

  // Loading QML file to play'Application.qml', function(err, window) {
    // window was opened

Customized Type

(This is experimental feature, API might be changed in the next version)

You can create a customized type in order to expose some APIs or functionality from Node.js to QML, see below:

var myQmlType = brig.createType('MyItem', {
	property: {
		prop1: 123
	method: {
		'readFile(a)': function(filename) {
			return require('fs').readFileSync(filename).toString();
	signal: [

// Triggered when instance of customized type was created
myQmlType.on('instance-created', function(instance) {

	// Signals
	instance.on('test', function(a) {
		// test(a) signal was emitted

In QML, we can import customized type with its type name and use it directly:

import Brig.MyItem 1.0


MyItem {
	// attributes...


Some exmaples you can found which used brig:


Here is a great countdown timer with Brig for hackathon event to show off, you can click image to play YouTube video:

Countdown Timer (clicks to play video)


Licensed under the MIT License


Copyright(c) 2015-2017 Fred Chien <>