For now the generation overwrites content. You can specify which entities you want generated via reveng.xml. Customization of what type of files you want generated is editable if you go to Run > Hibernate Code generation and edit the properties of the "generate entities" launch. (if you want the changes to stay around copy the launch and use the copy as the original gets updated when you run the seam generate entities wizard) About what all the files do I would recommend you read the Seam documentation about pages.xml navigation and/or ask on the seam forum. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4177295#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...