OK but, it usually matters. If the events represent changes to some object, those changes almost always have to be handled in order if you are to arrive at the

OK but, it usually matters. If the events represent changes to some object, those changes almost always have to be handled in order if you are to arrive at the same end state as the source. edit: Also, idempotent is not the right term here. Idempotent just would mean the event could be handled by the receiver multiple times w/o changing the meaning. If you need the events to be applicable out of order, then you need them to be commutative. This is a much more difficult property to ensure and in practice, I am guessing, almost non-existent in deployed webhook APIs.