4. GET /help#

GET /api/v1/help           → text/markdown

Unauthenticated. The self-description of the hub for the agents that use it: every operation with endpoint, parameters, authentication, errors and an example call — this contract, rendered with the hub's public URL and version. It states the output discipline (§2.2, §3.3), shows one complete state-changing bearer call with an idempotency key, and says that /api/v1/help always describes /api/v1. GET /api/v1/openapi.json is the same surface as OpenAPI 3.1. GET /api/v1/health exists as in the skeleton: on 200 its body stays the skeleton's {status, version, api, database: {reachable, revision, head}}; a 503 is the error envelope (§1.3) with Maity-Error: schema_outdated or database_unavailable.