Recently, over in a pull request review, we found the need to list all of the existing fedmsg topics (to see if some code we were writing would or wouldn't stumble on any of them).
Way back when, we added a feature to datagrepper that would let you list all of the unique topics, but it never worked and was eventually removed.
Here's the next best thing:
#!/usr/bin/env python from fedmsg_meta_fedora_infrastructure import ( tests, doc_utilities, ) from fedmsg.tests.test_meta import Unspecified classes = doc_utilities.load_classes(tests) classes = [cls for cls in classes if hasattr(cls.context, 'msg')] topics =  for cls in classes: if not cls.context.msg is Unspecified: topics.append(cls.context.msg['topic'] .replace('.stg.', '.prod.') .replace('.dev.', '.prod.')) # Unique and sort topics = sorted(list(set(topics))) import pprint pprint.pprint(topics)