The Python REST API has aggressive retry logic if the underlying call to the server incall_on_each_event does not succeed. This retry logic can obscure obvious problems such as somebody having an out-of-date API key or somebody not supplying the correct type of narrow arguments.

There are more details here:https://chat.zulip.org/#narrow/stream/137-feedback/topic/api.20client.20silent.20failure

You will want to discuss the best approaches on Zulip before proceeding, but the basic idea is to look for "UNAUTHORIZED" or "BAD_REQUEST" in thecode field that comes back from the server, and if you see those, you should immediately have the function either raise an Exception or somehow make it clear to the API author that they need to fix the problem.