To create a new Registration Module, implement the RegistrationModule interface. The main method of the RegistrationModule is onEvent() . This is where you put your code to handle a PURSe Event. See the PurseEvent documentation for details. See also org.ogce.purse.impl.GridSphereRegistrationModule in the source download for an example of a RegistrationModule.
See the PURSe Portlet Admin Guide for information on how to configure the PURSe Portlets to recognize your RegistrationModule.