The Ember.js REST Adapter expects the JSON to be returned as:
{ \"person\": { \"first_name\": \"Barack\", \"last_name\": \"Obama\",
You could also normalize it into something ember would expect.
App.PersonSerializer = DS.RESTSerializer.extend({ normalizePayload: function(type, payload) { var typeKey = type.typeKey; return { typeKey: payload } } });