The model layer contains your application's business logic, typically inside persistent entities or service objects. Models in a ColdMVC application serve two purposes: to represent individual records in your database through properties as well as to provide database access through an abstraction layer on top of Hibernate ORM.
To inject a singleton instance of a model into your components, simply add a property to your component with the name of model, prefixed with an underscore. For example, to inject a User model, just add property _User; to your component.
Models in ColdMVC contain several methods that help you easily query your database. Most of the methods are based on domain class methods found in Grails.