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Once you have implemented the lower-level APIs you can trivially provide a GORM API to a set of Grails domain classes. For example consider the following simple domain class:

[source,groovy]
----
import grails.persistence.*

@Entity
class Book {
    String title
}
----


The following setup code can be written to enable GORM for MongoDB:

[source,groovy]
----
// create context
def context = new MongoMappingContext(databaseName)
context.addPersistentEntity(Book)

// create datastore
def mongoDatastore = new MongoDatastore(context)
mongoDatastore.afterPropertiesSet()

// enhance
def enhancer = new MongoGormEnhancer(mongoDatastore, new DatastoreTransactionManager(datastore: mongoDatastore))
enhancer.enhance()

// use GORM!
def books = Book.list()
----

The key element for enabling the use of all GORM methods (`list()`, dynamic finders, etc.) is the utilization of the `MongoGormEnhancer`. This class is a subclass of `org.grails.datastore.gorm.GormEnhancer` and offers extensions to GORM specifically tailored for MongoDB. However, a subclass is not mandatory, and if you don't need any datastore-specific extensions, you can equally use the standard `GormEnhancer`:

[source,groovy]
----
def enhancer = new GormEnhancer(mongoDatastore, new DatastoreTransactionManager(datastore: mongoDatastore))
enhancer.enhance()
----