Optional ReadonlyidThe node's Node.id, for a node being restored rather than created (§79: "the engine assigns ids only to newly created objects").
Omit it — which is what every ordinary construction does — and the engine assigns the next counter value. Supply one and it is used verbatim and reserved, so no later node can be given the same id (2026-08-06, A-17). Ids are opaque strings: the format does not require them to look like the engine's own.
Construction options every node accepts (§6).
Subclass option interfaces extend this, so
idis available wherever a node is constructed; a subclass whose constructor takes no options at all inheritsNode's signature and accepts it unchanged.