We’ve been using this for a while in production and just made some security fixes today and added it to Rubygems:
and follow the directions in the README (it GitHub link above). It should work with Rails 3.1+ and 4+ (we use it in latest Rails 3.2.x currently). If you’re unfamiliar with the Rails 4 way of doing things (activemodel serializers), there will be a slight learning curve, but it is really quick to create new controllers.
Let me know what you think, and submit pull req’s/issues if you have any.