It focuses strictly on admission control: – bounds in-flight async operations – fails fast under saturation – never queues or waits – defines permit lifetime explicitly (admitted → terminal)

v0.3.1 is a small patch release that fixes cancellation classification in observability (wrapped CancellationException is now reported as CANCELLED), without changing runtime behavior.

I’m interested in feedback from people who’ve dealt with overload, fan-out amplification, or unclear async semantics in Java systems.