I'm having trouble saving data in this model relationship. My models are as follows: App.Flow = DS.Model.extend({ title: DS.attr('string'), content: DS.attr('string'), isCustom: DS.attr('boolean'), params: DS.hasMany('parameter', {async: true}) }); App.Parameter = DS.Model.extend({ flow: DS.belongsTo('flow'), param: DS.attr('string'), param_tooltip: DS.attr('string'), param_value: DS.attr('string') }); As you can see, I want Flows to have multiple Parameters. I have a rudimentary setup using Flow and Parameter fixtures, which behave as expected in the templates. However, when I try to create new ones in the controller, I have trouble setting the flow and parameter values correctly. var p = this.store.createRecord('parameter', { param: "foo", param_tooltip: "world", param_value: "hello" }); var f = this.store.createRecord('flow', { title: 'job', content: title, isCustom: true, params: [p] // doesn't seem to work }); f.set('params', [p]); // doesn't seem to work p.set('flow', f); // also doesn't seem to work // Save the new model p.save(); f.save(); I've tried a lot of solutions after staring at this and StackOverflow for a while (not just the ones listed). I'm not really sure what to try next. One thing that I noticed in the Ember inspector was that the ids of these created elements were not integers (they were something like the string 'fixture_0'), but I'm not really sure why that would be, whether its related, or how to fix it. Thanks!