Well, basically, I think these problem becomes much easier once you stop thinking in terms of "what layers should I have", and start thinking in terms of "what code do I have that is reusable when the client is not JSF, and what code do I have that is not reusable?", and then implement the reusable code into reusable Seam components. This doesn't stop you from thinking about component dependencies, and about separation of concerns - in fact it makes it easier. It's my strong belief that conceptualizing reusability in terms of "layers" has been the source of much evil in the Java world. I try to write reusable objects, not reusable layers. But this is not an approach that Seam forces upon you, it is just my approach. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4051282#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...