Hi @zmsoft 

The event hook provided, user_event_hook, must be a Python callable that accepts exactly one parameter - a dictionary representation of the event that triggered the execution of this event hook. The return value of the event hook has no significance. 

Please find an example here -

@on_event_hook
def my_event_hook(event):
   if (
       event["event_type"] == "update_progress"
       and event["details"]["update_progress"]["state"] == "STOPPING"
   ):
       print("Notified that update is stopping: ", event)