"alesj" wrote : I see that a couple of classes from .spi reference some of the .plugins classes. | I saw the same problem with my BeanMetaDataBuilder - moved impl details in the plugins. | Shouldn't we keep them separate -> only plugins depend on spi? No. API/SPI is always allowed to reference plugins. Otherwise factories wouldn't be able to define a default implementation for example. The important part is that the implementation doesn't leak out to the client code, e.g. by appearing as parameters on methods. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4041345#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...