Initiated by Roy Fielding's dissertation, there has been miles of paper written on how to structure the HTTP payloads for machine-to-machine communication. Unfortunately not nearly as much attention has been dedicated transmission of the intent of these payloads.

The specification is clear about the meaning of the verbs e.g. that GET should not change state and PUT should be idempotent. But how exactly can one design a HTTP channel between two software components so that the intent of one is transmitted exactly-once to the other?

In this talk we are going to explore some well-known and not-so-well-known approaches to ensuring the action requested by means of a HTTP request is conducted exactly once.