These are the properties the runtime holds for every node, whether the caller is React, the client, a test, or a script.

Invariant	What it means
Deterministic identity	A node’s id is `tag:key`, where `key` is pure and deterministic. The same tag and args always resolve to the same node. See Identity and keys.
Static dependency topology	A node’s dependency set is fixed once wired. Args reconciliation cannot change which nodes it depends on. See Dependencies.
Dependency-first readiness	A node cannot be ready until every node it depends on is ready.
Wiring failure ≠ driver failure	A planning failure (bad key, cycle, duplicate tag) makes the node invalid; it is not a driver/readiness failure.
Readiness failure is retryable	A failed `acquire` leaves the node retryable — calling `ensureReady()` again starts a fresh attempt. See Errors.
Stable pending attempt	Concurrent callers awaiting readiness join the same in-flight attempt; they do not each start their own.
Per-node serialized work	Driver work for one node id runs serialized. A stale request cannot commit over a fresh one; two actions cannot interleave.
Refresh ≠ retry	Refresh updates a ready node in the background and rolls back on failure; it is distinct from retrying a readiness error.
Operation failure ≠ readiness failure	A failed action or refresh leaves the node ready with an operation failure; it does not poison readiness. See Lifecycle.
Expired data is hidden	An expired result is not exposed to ordinary reads; active consumers reload it through readiness. See Result validity.
Release ≠ eviction	Release clears resources but keeps identity and edges; eviction removes the graph record and edges. See Eviction and release.
Liveness ≠ React presence	Driver live work is driven by observation and manual leases, not by a component mounting. See Liveness.
Owned cleanup	Node and driver cleanup runs through disposer bags and the driver `release` hook, on one graph-owned path.
Caller-independent	The same contract holds for every caller; it does not depend on the UI disabling a control.

Underneath all of these: every lifecycle fact has exactly one owner, the runtime.

Next: Testing.

Runtime invariants