jsonwebtoken doesn't retrive me a token

I am using nodejs and sequelize to create simple user registration, i already did the login and register, but when login is success i don't get any token, tried to console.log the token to see if i get some result, but there is no response in the console related to the token :S.

Here is my code:

var express = require('express');
var User = require('../../models').User;
var router = express.Router();
var jwt = require('jsonwebtoken');
var app = require('../../app');

/*var token = jwt.sign(user, app.get('superSecret'), {
  expiresInMinutes: 1440 // expires in 24 hours
});*/

router.post('/', function (req, res, next) {
  if (JSON.stringify(req.body) == "{}") {
    return res.status(400).json({ Error: "Login request body is empty" });
  }
  if (!req.body.username || !req.body.password) {
    return res.status(400).json({ Error: "Missing fields for login" });
  }


  // search a user to login
  User.findOne({ where: { username: req.body.username} }) // searching a user with the same username and password sended in req.body
    .then(function (user) {
      if (user && user.validPassword(req.body.password)) {
        //return res.status(200).json({ message: "loged in!" }); // username and password match

        // create a token
        var token = jwt.sign(user, app.get('superSecret'), {
          expiresInMinutes: 1440 // expires in 24 hours
        });

        // return the information including token as JSON
        res.json({
          success: true,
          message: 'Enjoy your token!',
          token: token
        });
      }
      else{
        return res.status(401).json({ message: "Unauthorized" }); // if there is no user with specific fields send
      }
    }).catch(function (err) {
      return res.status(500).json({ message: "server issues when trying to login!" }); // server problems
    });
});

module.exports = router;

via Antonio Costa