Points To Remember You need to add the @Validateable annotation to the command class. Use importFrom in the constraints block with the domain name to import the constraints from domain. How to add Constraints to the Command Object. Lets us look at the example below. We have created a Domain by name User and a Command object by name UserCommand. We have created the constraints for email, password, first name and last name in User domain. We will import these constraints from domain to the command object and add some more constraints like verify password( if password and confirm password match). User.groovy package com.ekiras.domain class User { String email String password String firstName String lastName static constraints = { email(nullable: false, blank: false, unique: true, email:true) password(nullable: false, blank: false) firstName(nullable: false, blank: false) lastName(nullable: false, blank: false) ...