gistfile1.js

// Setup backbone to handle auth tokens
        // in all it's requests by override the sync method.
        _setupAuthToken: function() {
            var _sync = Backbone.sync;
            Backbone.sync = function(method, model, options) {
                options = options || {};
                options.beforeSend = function(xhr, options) {
                    var _data = options.data;
                    var newData = _.extend(JSON.parse(options.data), {
                        auth_token: IS.currentUser.get('authToken'),
                        api_key: IS.CONSTANTS.API_KEY        
                    });
                    options.data = JSON.stringify(newData);
                };
                _sync.call(this, method, model, options);
            };
        }