Spec and conformance

spec/SPEC.md states numbered requirements (RFC 2119) for inputs, evaluation order, outcomes, shadow mode, time, stores and budgets, policies and presets. spec/SPEC_VERSION is independent of the package versions.

Fixtures under spec/fixtures/<area>/<name>.json carry a policy, an optional store seed, and tests with an input and the expected decision fields: allowed, trace, rejectedBy, deferredBy, retryAt, deliverAt, surfaces, shadowed, nearLimit, a reason_pattern, and after commit, store_after. They cover the DST edge in America/New_York, Pacific/Apia, a wall-clock case in 2031, atomic commit, the ISO week, deferral, shadow mode, the optional checks and four presets.

An implementation conforms when it passes every fixture for its spec version, minus the names in spec/skip/<impl>.txt, which must be empty at a stable release.

npm test                          # TypeScript: spec-lint, then one test per fixture
npx proactive-gate replay --fixtures spec/fixtures
cd python && pytest               # Python: every fixture through Gate and AsyncGate

Writing a second implementation? Start from the fixtures, not from the TypeScript source. The reasons in the fixtures are matched by pattern, so wording may differ; the trace, the stopping check and the store keys may not.