Configure the health checks contract

Implement types or schemas around GET /livez and GET /readyz so illegal states are unrepresentable at the boundary. For Kubernetes liveness vs readiness for retrieval-and-generation API, trusted inputs come from sessions, signatures, pinned digests, or workload identity — not from free-form model text. cluster operator during vector DB maintenance window should be able to read the contract and know which fields are optional, which are enumerated, and which abort the request. Constructors and boot paths must not perform provider side effects; injection points keep tests honest.

Document required env vars in .env.example with placeholders only. Rotation story belongs later, but the contract already forbids printing secrets and forbids defaulting to fail-open when a dependency is missing. Invariant to encode in types/tests: /livez only checks process; /readyz checks vector+model deps; wrong probe kills healthy pods. If a config number lacks units, fix the name (timeout_ms, rpm_hard) before writing logic.

Create fixtures for the golden path and for PROBE-RESTART-STORM-8. Name files after the behavior (429-retry-after.json, cross-tenant.json, empty-citation.json) rather than test1. Each fixture carries expected status/code. This kit is the shared language for validation and failure pages.

Compatibility promise: additive fields may appear only if readers ignore unknowns safely; breaking changes bump a version visible on the wire. For AI payloads, size limits arrive before JSON parse when hostile blobs are a risk. Document how clock skew, idempotency keys, and tracing headers travel through Kubernetes liveness vs readiness for retrieval-and-generation API. If you use feature flags later, the contract already states that flags are not authorization. Link each config knob to a unit and a failure mode (“0 means disabled” vs “0 means divide-by-zero”). A peer reviewing the PR should find PROBE-RESTART-STORM-8 named in a comment on the adversarial fixture.

Generate OpenAPI or a typed client only after the hand schema is stable for one fixture round-trip. Record how errors look on the wire — problem+json, envelope, or bare status — and stick to one. Clock sources must be injectable for skew tests. If webhooks appear later, document signature header names now even as TODOs. Keep sample payloads UTF-8 and free of real emails. Add a makefile or npm script that validates schemas without network. In this chapter the product is Kubernetes liveness vs readiness for retrieval-and-generation API, the human stakeholder is cluster operator during vector DB maintenance window, and the incident id you design against is PROBE-RESTART-STORM-8. Re-state the oracle in your notes — vector pause → readyz 503, livez 200, no restart loop; process deadlock → livez fails → restart — and keep the invariant visible: /livez only checks process; /readyz checks vector+model deps; wrong probe kills healthy pods. Track restart_count == 0 during dep outage and ready_pods ≥ 1 when deps healthy as the scoreboard. Surface under change control: GET /livez and GET /readyz. If you only have forty minutes, finish the fixture for readyz embedded in liveness → restart storm during dependency blip before polishing UI. Promotion language stays ternary: promote, hold, or roll back based on evidence, not hope.