Install nw-builder

npm install nw-builder -g

create build configuration script

For example build-standalone.js file, something likes below:

var NwBuilder = require('nw-builder');
var nw = new NwBuilder({
    files: './path/to/nwfiles/**/**', // your files
    platforms: ['osx64', 'win32', 'win64'], // the platform you want to publish
    version: '0.34.2-sdk' // nw js version

// Log stuff you want
nw.on('log',  console.log); () {
   console.log('all done!');
}).catch(function (error) {

run script to build prject

npm run-script build-standalone