How do I make an arbitrary HTTP request to an API?

I’m trying to do something like what is described here:

I already have an API that works with the RESTAdapter. However, I am trying to add new API routes that Ember.js can call that will kick off various server-side actions, some of which update records and some do not.

TIA!

Update:

Am trying this, just manually making an ajax request using Ember’s jQuery.