Route's model hook JSON conventions


Hi all,
since it’s not totally clear to me reading the docs, I would like to ask what conventions ember use for a JSON API response triggered by the model hook in a route. To better put it: what kind of response from an API request ember expects in terms of JSON structure?
These are the conventions implied by the use of Ember-Data. However, regarding route’s model hook the expected JSON structure is not specified.

Anyone could clear this point?