discourse/app/assets/javascripts/admin/routes/admin_customize_route.js

/**
  Handles routes related to customization

  @class AdminCustomizeRoute
  @extends Discourse.Route
  @namespace Discourse
  @module Discourse
**/
Discourse.AdminCustomizeRoute = Discourse.Route.extend({

  model: function() {
    return Discourse.SiteCustomization.findAll();
  }

});