Ember.js + Node.js Authentication/Session Not Working with Express.Session-Collection of common programming errors

I have been experimenting with Ember.js and Node.js, and have run into a problem. I have protected my API routes on the server with the standard Express.session system, but I have run into a problem when those APIs are serving an Ember.js application. Since the Ember app does not have the ability to store values in req.session, my app doesn’t function. How should I do my authentication so that I still can session-protect my API? Here is some of my current server login code:

a “check login” function:

var checkLogin = function(req, res, callback) {
    if (req.session.user) {
      callback();
    } else {
      res.send({error: "AuthRequired"});
    }
  };

Error when Ember makes a request:

TypeError: Cannot read property 'user' of undefined

Middleware setup:

app.configure(function () {
  app.use(express.bodyParser());
  app.use(express.static(__dirname + '/static/'));
  app.use(express.cookieParser());
  app.use(express.session());
  //to not care about invalid JSON requests
  app.use(function(err, req, res, next) {
    if (err.message == 'invalid json')  {
        next()
    } else {
        next(err)
    }
  });
});