Compatibility tiers

Referencedraft

Work is ordered by compatibility rather than by feature. Each tier is a gate, and a gate opens on a demonstration with captured output.

Tier Scope Gate
Connect Executor handshake, authentication, heartbeat, executor listing Sample applications in at least two SDK languages appear in the executor listing
Observe Read operations across workflows, queues, schedules, steps, events, notifications, streams, and aggregates The conformance suite and the upstream client's read commands pass
Operate Cancel, resume, fork, delete and their bulk forms; schedule control; export and import; versions Conformance and the upstream client's mutation commands pass
Recover Disconnected and dead state machine, recovery dispatch, confirmation, executor cleanup Chaos test: kill one executor of several, every workflow completes elsewhere, no outcome runs twice
Scale Ownership and peer forwarding, metrics, alert rules, retention, audit log Two instances behind a proxy route correctly and a metrics scrape works
Dashboard The web interface Manual acceptance checklist
Identity OIDC, users, organisations, roles, permissions, and the operations that require them The upstream client's device login works against Relay and a test identity provider in CI

The tiers are also the milestone plan. A tier is never partially claimed. If the acceptance condition has not been demonstrated, the tier is open, however much of its code exists.