I don't know if this is realy possible.
I'm trying to use JPA entities (with annotations) via Hibernate Configuration, but is sending me an error:
org.hibernate.MappingNotFoundException: resource: org/rds4jpa/base/config/domain/KeyGroup.hbm.xml not found

I don't have hbm.xml files since it is JPA annotated.
My configuration:

Configuration cfg = new Configuration();

cfg.setProperty("hibernate.dialect", "org.hibernate.dialect.PostgreSQLDialect");

cfg.setProperty("hibernate.connection.driver_class", "org.postgresql.Driver");
cfg.setProperty("hibernate.connection.url", "jdbc:postgresql://localhost:5432/jpa_test");
cfg.setProperty("hibernate.connection.username", "postgres");
cfg.setProperty("hibernate.connection.password", "***********");

cfg.setProperty("hibernate.show_sql", "true");
cfg.setProperty("hibernate.hbm2ddl.auto", "create-drop");

//org.rds4jpa.base
cfg.addClass(KeyGroup.class);
cfg.addClass(KeyValue.class);

//org.rds4jpa.audit
cfg.addClass(Audit.class);
cfg.addClass(AuditLine.class);

//org.rds4jpa.security
cfg.addClass(User.class);
cfg.addClass(LinkUserRole.class);
cfg.addClass(Role.class);

Sorry, my bad!!
I need to use addAnnotatedClass(...) instead of addClass(...)