Unique record ID (distinct from the command's meta.id, which is re-stamped on replay).
The command's action name.
The command's target, exactly as dispatched.
OptionalpayloadThe command's payload, exactly as dispatched.
The idempotency key derived at ENQUEUE time. Replays stamp this original
key onto cmd.meta.idempotencyKey, so the backend sees the same
Idempotency-Key header for every delivery attempt of this command.
Date.now() at enqueue time.
A queued command awaiting replay. JSON-serializable by design —
targetandpayloadround-trip through the storage adapter, so keep them plain data (no functions, no DOM nodes) for actions routed through the outbox.