I talked to Michael privately... and we both agreed it would be nice to have an API to configure that. We should definetly have a constructor with a list of immutable objects, but it would be nice also to have some sort of annotation... maybe an empty interface (implements org.jboss.jbser.UserImmutable). or any other options. This way, if an user has a immutable object, such as.. InvoiceID, EAN... or whatever... maybe users would be able to make usage of that even under frameworks such as EJB, Seam or JBossCache. I'm wondering what would be the simplest and more intuitive API possible here. I will make up something next week and I will post on this thread before coding it. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4034306#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...