whats the term used to describe sending the same message to a system and receiving the same response
I"m looking for a term here.
in messaging systems you send a request, and it processes and sends a response.
if that same request is sent it should return the same response, (but not necessarily process the details)
This would be like submitting financial details twice.
Is the term "idempotent" what you have in mind?
I think idempotent is the word you're looking for.
Wikipedia says: "Idempotent operations are operations that can be applied multiple times without changing the result."
I think memoization might be what you're looking for.
A memoized function "remembers" the results corresponding to some set of specific inputs. Subsequent calls with remembered inputs return the remembered result rather than recalculating it...
Not sure if that's what you're looking for though.