import barcode = require('barcode'); import path = require('path'); var code39 = barcode('code39', { data: "it works", width: 400, height: 100, }); code39.getStream(function (err, readStream) { if (err) throw err; // 'readStream' is an instance of ReadableStream }); var outfile = path.join(__dirname, 'imgs', 'mycode.png'); code39.saveImage(outfile, function (err) { if (err) throw err; console.log('File has been written!'); });