Hi, I've read this How-To http://www.zope.org/Members/tazzzzz/addZClasses But I'm deadly trying to do this in a python script (that's not a ZClass method and does not reside in a product), an not in an external method. I've deeply tried to find a way but did not succed. The creation of ZClass instances through ZMI works perfectly , through the usual MyProduct/MyZClass_addForm and MyZClass_add All I do is this (translation into python script of the DTML method from above mentioned URL): context.REQUEST.set('id', myNewId) context.manage_addProduct['MyProduct'].MyZClass_add(_.None, NoRedir=1) return 'Done' I got this... Error Type: NameError Error Value: MyZClass [VERY LONG TRACEBACK FINISHING WITH] (Object: MyZClass_add) File /usr/local/Zope-2.3.3-linux2-x86/lib/python/DocumentTemplate/DT_With.py, line 138, in render (Object: MyZClass.createInObjectManager(REQUEST['id'], REQUEST)) File /usr/local/Zope-2.3.3-linux2-x86/lib/python/DocumentTemplate/DT_Util.py, line 339, in eval (Object: MyZClass.createInObjectManager(REQUEST['id'], REQUEST)) (Info: REQUEST) File <string>, line 0, in ? NameError: (see above) Does someone have an idea ? Many thanks in advance ! --Gilles