Saving model according to JSON-API


I’m using Ember.js 2.7 and Ember Data 2.8 I have model User which has reference one-to-one UserMetum and has reference has-many Specializations. I have edit user form which affects to these three models. During saving I have a trouble how serialize in right way. First way. It’s adding attributes to relationships. I found lib frank06/ember-data-save-relationships for this way. But it doesn’t correspond to JSON-API specification. Second way. It’s serializing each model and send it to API. But it requires redundant requests to API server. Third way. Your’s?