Verified against Semitexa Ultimate 2026.09.19.1020

Payload Parts

A payload can be extended by another module without reopening the original route class, so one transport boundary can stay singular while modules stay additive.

How it works

A base module declares the payload with one of the access attributes (#[AsPublicPayload], #[AsProtectedPayload], or #[AsServicePayload]). Another module contributes a trait marked with #[AsPayloadPart(base: ...)]. At runtime PayloadFactory composes a wrapper class that extends the base payload and uses all matching traits, so the added trait can own setters and guards for its own extra fields.

Why this matters

This solves a painful modularity problem: extra request concerns do not force a fork of the original payload and do not leak into untyped arrays. The handler still receives one trusted DTO, and each added concern can validate its own field without a central validate() choke point.