How it fits
The design separates deciding that an effect is allowed from carrying it to an external destination. Keryx concerns the latter and the evidence returned from delivery.
Keryx
Keryx names a delivery role in the documented Sven architecture: project or deliver an authorized effect, then return a receipt or observation of what happened.
Responsibility
Delivery cannot manufacture permission, trust or evidence validity. A receipt must be interpreted within the scope of the specific operation.
Information in
An authorized delivery request with a defined source and destination.
Information out
A delivery result and attributable receipt or failure observation.
This is a documented architectural role. It is not an announcement of a generally available standalone service.