Optional ReadonlytransientWhen true, the observer is registered as a one-shot: the engine
fires it on the first commit whose Phase G dispatch passes the
usual Object.is equality cutoff for the observed node, then
auto-disposes the registration before the commit returns. A
subsequent commit on the same graph never sees the observer
again.
Subtleties:
transient
is "fire at most once," not "exists for at most one commit." A
caller that needs the latter constructs a normal subscription
and unsubscribes from inside the observer.subscribe, and its purpose
is to surface the current value to the new observer, not to
satisfy the one-shot contract. The engine treats the initial
fire as bookkeeping (hasFired flips), and the auto-dispose
trigger is the next Phase G fire.Defaults to false — the engine retains the registration across
commits as the canonical Graph.subscribe contract requires.
Optional knobs accepted by Graph.subscribe and Graph.subscribeMany (#766).
Remarks
The bar for adding a field here is the same as for adding a public method on Graph: name an unavoidable concept the engine cannot express without it.
transientclears that bar — adopters routinely want a "fire once then unmount" observer to react to a one-shot derived signal (e.g. SSR-hydrate completion, acommitMetadataDerivedthat publishes "the just-completed commit is the one I was waiting for") without leaking a manualunsubscribe()into every consumer call site. The engine drops a transient observer at the end of the same commit pass that fired it, so subsequent commits never see it again.