Trace corpus

Fixtures for the golden-corpus tests (crates/mcp-trace-validator/tests/golden.rs):

• good/ — sessions that must validate with verdict pass.
• violations/ — single-issue sessions, each falsifying at least one check; named after the requirement whose check they exist to kill.
• golden/ — the byte-pinned expected report for every trace. Regenerate only via cargo xtask bless and review the diff like code.

Violation naming contract

A violation trace is named area-nnn-<slug>.jsonl and must produce a Fail/Warn row with findings for exactly requirement AREA-NNN — the golden harness enforces the attribution by name (violation_traces_fail_and_match_goldens), so a defect re-routed to a different requirement cannot re-bless silently. A stem that does not begin with a requirement ID fails the suite loudly.

Provenance ledger

Every trace’s origin, in one reviewable place that survives history rewrites (the invariant test in golden.rs fails if a trace is added without a ledger row). All current traces share one provenance: hand-authored for this repository as synthetic sessions (no third-party traffic, no recorded production data), written against the 2025-11-25 spec text fetched live from modelcontextprotocol.io on 2026-06-09 (re-verified clause-by-clause against the live text on 2026-06-11) and validated against the embedded registry at the commit that introduced them. Traces produced by capture tooling (roadmap M3) will record the capturing implementation and revision here.

good/

violations/

Each file injects exactly the violation its name states; golden/ shows the full expected report, including any intrinsic secondary findings the injected defect causes (a malformed notification also fails lifecycle accounting, for example).