var repl = new ReplitClient(
  'api.repl.it',
  '80',
  'ruby',
  token
);

repl.connect().then(function() {
  return repl.evaluate(
    'puts "hello world"',
    { stdout: function(out) { console.log(out); } }
  );
}).then(function(result) {
   console.log('result: ', result.error || result.data);
});