As announced we published the official node.js API Wrapper.
var fs = require('fs');
var cloudconvert = new (require('cloudconvert'))('your_api_key');
cloudconvert.convert({
inputformat: 'png',
outputformat: 'jpg',
file: fs.createReadStream('tests/input.png'),
converteroptions: {
quality : 75,
}
}).on('error', function(err) {
console.error('Failed: ' + err);
}).on('finished', function(data) {
console.log('Done: ' + data.message);
this.pipe(fs.createWriteStream('out.jpg'));
}).on('downloaded', function(destination) {
console.log('Downloaded to: ' + destination.path);
});