One option that just came into my mind is an CN-in...

# ktor

[orangy]

One option that just came into my mind is an CN-interceptor.

install(ContentNegotiation) {
   …
   intercept<Parameters> {
      // called when instance of Parameters is being sent (before transform) or received (after transform)
   }
   intercept<Entity> {
   // called when instance of Entity (or derived) is being processed
   }
   intercept<Any> {
   // any instance, called if more specific type interceptor is not found. Or may be call all matching interceptors
   }
}

[orangy]

@wouterdoeland would it work for your use case?