@devinivy thank you, that's a great lead, it looks a bit more finished than PouchDB, I'll give it a try. I am just looking for an "offline first database". I think that is probably one of the next logical steps on Single-State-Tree SPA. I guess my first question for him is how can I sync Model/Session and Entities. For instance I am working on a Purchase Order, so I have something like model.data.currentPO, how can I tell the database to apply all changes to the entity where PO.id = "123"?