PLATFORM RC-99 (no-op) — Webhooks merchant harness (v1) (rc99)

RC-99 defines a deterministic, offline merchant harness for webhooks. It executes the RC-97 receiver handler samples against the canonical RC-96 fixture suite and produces sealed integration evidence.

This OpenAPI document is contract-only:

• It intentionally defines no HTTP endpoints (paths: {}).
• It exists so the public API reference (Redoc) can document the harness artifacts and summary schemas.

Canonical RC docs:

• docs/rc/rc99.md
• dependencies: docs/rc/rc96.md, docs/rc/rc97.md

Offline harness artifacts and deterministic summaries used as integration evidence.