There isn't really a mapping between backbones models and protorpc. Backbone.js assumes the model layer is RESTful where protorpc assumes you will make method calls, each via a POST call.

I'm interested in what a model layer would look like using protorpc. One idea is to take a similar path of abstraction as the underlying appengine datastore api does: use protocol buffers to express an "entity". So you might have:

    { 
      entity_type: 'Book',
      entity_fields: [ 
        { 
          field_type: int,
          field_name: 'title',
          required: true
        }
      ]
    }

This would be a proto definition called, "Entity". From here you could build procedure calls that send entities for doing common routines, such as updates, or deletes. If you can make a structure like this work, you can build an api with javascript which hides the protobufs from you all together.. When you call Model.get('Book').create({title: 'My book'}), it constructs the Entity protobuf and calls the remote call for creating a new entity.

Just an idea! Also - protorpc is in fresh development, so it's a good idea to join the discussion group and make suggestions: https://groups.google.com/forum/#!forum/google-protorpc-disc...