Stable event identifier within its owner subtree.
OptionalmetaOptional metadata used by docs and tooling.
OptionalparallelIf true, listeners with the same priority run concurrently within a batch. Batches (grouped by order) still execute sequentially in priority order.
OptionalpayloadOptional validation schema for runtime payload validation. When provided, event payload will be validated when emitted.
OptionaltagsTags attached to the event for routing or policy decisions.
OptionaltransactionalIf true, listeners run in transactional mode and must return an undo closure.
Declarative event definition contract.