Interface RouteMapperOptions<IncomingEventType, OutgoingResponseType>

Module props that compose down a group instead of being replaced by the child's value.

The router carries module props without knowing them, and the default merge is child-wins, which is right for most: a child's contract is its contract. Some props are gates, and a gate declared on a group must hold for every child on top of the child's own: authz above all. A module declares its own key composable through its blueprint (stone.router.composableProps), so the router still names no module. Parent first, for the same reason group middleware runs first: a group encloses its routes.