I'm trying to figure out how the error handling works. I added something like this in my __init__.py def _q_exception_handler(request, exception): import traceback import StringIO s = StringIO.StringIO() request.response.set_content_type("text/plain") traceback.print_exc(file=s) return s.getvalue() When i try this on the demo module. I'm wondering why the PublishError is caught but not the ValueError.. Another question: What sould i do if i want to have this error handler for each request ? In fact i'm in developppement stage right now. And reading traceback in apache log is painfull. Bye Bye..