I've used a similar approach for Flask-Potion, a REST API framework (http://potion.readthedocs.org/ http://potion.readthedocs.org/). References are JSON objects

I've used a similar approach for Flask-Potion, a REST API framework (http://potion.readthedocs.org/ http://potion.readthedocs.org/). References are JSON objects in the format {"$ref": uri}, which makes them exceedingly simple to fetch and cache.