freshness-contract

# /freshness-contract > **EXPERIMENTAL.** A lookup, not a judgment ritual: it should cost LESS than the vibes it replaces. Fires only when prior evidence is about to be **reused for a decision** — never on every read, never as per-phase bookkeeping. It decides whether old proof still counts; what fresh proof must show belongs to your verification tools. The design is deliberately isomorphic to HTTP caching (RFC 9111): explicit invalidation beats heuristics, conflicting signals resolve restrictively, and nothing is served stale silently. No TTL numbers ship in v1 — every "how old is too old" constant would be invented; the table routes by *class and events*, which are observable. ## Step 1 — classify the artifact (volatility class) | Class | Meaning | Examples | |---|---|---| | **stable** | **exact version-pinned evidence, used for a question about that exact version** — byte stability is not applicability: a superseded spec's old bytes still match while the governing version moved | a released spec consulted AS that release, a frozen/hash-pinned artifact, an archived record. **Supersession or a dependency-version change is a named invalidator whenever the decision asks what is CURRENT** | | **write-coupled** | valid until someone writes to the source | a file you read this session, an index entry, a config, a map/roster document | | **env-coupled** | valid until the environment shifts | a passing test that touches network/services/installed tools, a capability probe, a bu...