As part of amazing goodies of grails is the ability to extend your applications - registering new classes problematically is a breeze
GenericApplicationContext context = new GenericApplicationContext(); context.setParent(applicationContext); /* OR */ context.setParent(grailsApplication.mainContext); // Create class from string Class clazz = new GrailsAwareClassLoader().parseClass(classString); // First create a bean definition def myBeanDef = new GenericBeanDefinition() // Set bean class myBeanDef.setBeanClass(clazz) // Set scope myBeanDef.setScope(BeanDefinition.SCOPE_SINGLETON) context.registerBeanDefinition("beandefName", myBeanDef);