Request-free · bounded policy model

fetchLater vs sendBeacon decision lab

This lab creates a decision and quota receipt only. It is not a browser-compatibility snapshot or empirical delivery-rate test, and it never issues a request.

Scenario

MethodHeader profileLifecycle Activation delay · 0–600000 msAvailable deferred budget · 1–655360 bytesBody · at most 4096 characters fetchLater feature detected Beacon API feature detected Client must read a response Event may retry / requires durable handling Stable idempotency key present Server reconciliation exists

Recommended policy

Independent check ledger

Gate	Input	Result	Reason

fetchLater vs sendBeacon decision lab

Scenario

Recommended policy

Independent check ledger

Semantic mutation fixtures

Canonical receipt