Y.User = Y.Base.create('user', Y.Model, [Y.ModelSync.REST], {
                                                    root: '/users'
                                                });
                                                
                                                var currentUser, newUser;
                                                
                                                // GET the user data from: "/users/123"
                                                currentUser = new Y.User({id: '123'}).load();
                                                
                                                // POST the new user data to: "/users"
                                                newUser = new Y.User({name: 'Eric Ferraiuolo'}).save();
                                                

When sub-classing Y.ModelList, usually you'll want to ignore configuring the root and simply rely on the build-in convention of the list's generated URLs defaulting to the root specified by the list's model.

Y.User = Y.Base.create('user', Y.Model, [Y.ModelSync.REST], {
                                                    root: '/users/'
                                                });
                                                
                                                var currentUser, newUser;
                                                
                                                // GET the user data from: "/users/123/"
                                                currentUser = new Y.User({id: '123'}).load();
                                                
                                                // POST the new user data to: "/users/"
                                                newUser = new Y.User({name: 'Eric Ferraiuolo'}).save();
                                                

If a url is specified, it will be processed by Y.Lang.sub(), which is useful when the URLs for a Model/ModelList subclass match a specific pattern and can use simple replacement tokens; e.g.:

Y.User = Y.Base.create('user', Y.Model, [Y.ModelSync.REST], {
                                                    root: '/users',
                                                    url : '/users/{username}'
                                                });
                                                

Note: String subsitituion of the url only use string an number values provided by this object's attribute and/or the options passed to the getURL() method. Do not expect something fancy to happen with Object, Array, or Boolean values, they will simply be ignored.

If your URLs have plural roots or collection URLs, while the specific item resources are under a singular name, e.g. "/users" (plural) and "/user/123" (singular), you'll probably want to configure the root and url properties like this:

Y.User = Y.Base.create('user', Y.Model, [Y.ModelSync.REST], {
                                                    root: '/users',
                                                    url : '/user/{id}'
                                                });
                                                
                                                var currentUser, newUser;
                                                
                                                // GET the user data from: "/user/123"
                                                currentUser = new Y.User({id: '123'}).load();
                                                
                                                // POST the new user data to: "/users"
                                                newUser = new Y.User({name: 'Eric Ferraiuolo'}).save();
                                                

When sub-classing Y.ModelList, usually you'll be able to rely on the associated model to supply its root to be used as the model list's URL. If this needs to be customized, you can provide a simple string for the url property.

Y.Users = Y.Base.create('users', Y.ModelList, [Y.ModelSync.REST], {
                                                    // Leverages Y.User's root, which is "/users".
                                                    model: Y.User
                                                });
                                                
                                                // Or specified explicitly...
                                                
                                                Y.Users = Y.Base.create('users', Y.ModelList, [Y.ModelSync.REST], {
                                                    model: Y.User,
                                                    url  : '/users'
                                                });