Trouble while accessing HTTP server for JSON api

Hi i am trying to access JSON api to be used in my Front end Ember app but had problem with the back end (Express app).

Right now i am sending res as res.json(status, (json)); and is not working for some reason, but when i used ryan florence’s addressbook api example it worked, so i guess my back end is not configured properly.

I would appretiate if someone can guide me how to configure backends to respond in a Ember friendly way.

Thanks

Update

I just checked that my express app was not configured for CORS, all i have to do is follow this stackoverflow answer Allow CORS REST request to a Express/Node.js application on Heroku - Stack Overflow and it worked.