Is always necessary the persistence layer ?

I'm creating a project that only show forms, get the information invoking diferents webservices and show forms with the results of the webservice invoked.So I'm not acceding to any BBDD.

Can Roo support a project without defining the persistence? Or I need to define an existing database even if I don't use it ?

Now Roo requires persistence setup before allow entity and field creation.I can remove the @RooEntity annotation from domain objects. This annotation and related AJ attach object with persistence system. However, web scaffold search @RooEntity entities to generate web layer (controller, jspx, etc.).