whats the term used to describe sending the same message to a system and reciving the same response

Question

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.

Answer 1

Echo?

Not sure if that's what you're looking for though.

Answer 2

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...

Answer 3

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."

Answer 4

Is the term "idempotent" what you have in mind?