I was looking up documentation and posts on ember.js, and using ember.js with Rails.
I like the idea of Rails providing the API, and ember.js handling the UI, but I was
Check ember-auth it handles token authentication for ember.js and there is also a demo and tutorial for rails / devise / ember. ember-auth is the best approach I've seen so far to authenticate an ember.js / rails app.
So far I have implemented a basic Ember application based on Ember-auth with Devise token authentication and example Oauth for Google and LinkedIn that can be found here and is live here: https://starter-app.herokuapp.com