gistfile1.js

{ [ { id: "32111aae", spot_number: "BAH", commercials: [{ id: "33321eaz", title: "yar"}] } ] }

 Binder.Spot = DS.Model.extend({
    spot_number: DS.attr('string')
  });

  Binder.Commercial = DS.Model.extend({
    title: DS.attr('string'),
    spot: DS.belongsTo(Binder.Spot)
  });
  
  Binder.Spot.reopen({
    commercials: DS.hasMany(Binder.Commercial)
  });

  DS.RESTAdapter.map(Binder.Commercial({
    spot: {
      embedded: 'always'
    }
  }));