anchor-x402 serves an AI Catalog
manifest at /.well-known/ai-catalog.json on api.anchor-x402.com, declaring
3 agentic resources
that a discovery service can index without asking anyone’s permission.
did:web:anchor-x402.com —
resolving it returns 404. A did:web: that does not resolve is a string, not an identity, and does not earn the identity affordance here.
/.well-known/ai-catalog.json. ARD v0.91 renamed the path to /.well-known/ard.json and made the old one an optional courtesy, so a consumer implementing only the current spec will not find this manifest.
specVersion in the manifest. 1.0 is current for the AI Catalog data model; anything lower is an earlier draft. ARD reads this field as transport-defined and ignores it.content-type-not-ai-catalog-jsondid-web-does-not-resolveentry-no-representativeQueries18 x402-paid services for AI agents — on-chain anchoring/attestation, wallet screening & due-diligence, Web3 data, verifiable signed RNG, LLM utilities, and x402 spend accounting. Pay-per-call USDC, no API keys, no accounts.
The same 18 services over MCP Streamable HTTP. server/discover, initialize and tools/list are free; tools/call settles per request in USDC via x402 (PAYMENT-SIGNATURE header). Stateless, no API key.
OpenAPI 3 spec for all 18 paid services, annotated with x402 payment metadata (per-route price and accepted rails). This is the authoritative per-route pricing source.
Content-Type: application/json —
yesAccess-Control-Allow-Origin: * —
yeshttps://api.anchor-x402.com/.well-known/ai-catalog.json on 2026-09-13, HTTP
200. The verbatim body is stored alongside its manifest in the
anchor-x402 repository
as ai-catalog/anchor-x402-ai-catalog.json. Nothing on this page is derived
or generated: an AI Catalog manifest is served from the publisher’s own domain or it does not
exist, which makes it — like an
A2A Agent Card — one of the few agent artifacts that cannot be
produced on a provider’s behalf. Grades are recomputed on every build; the specification is a
v0.9 draft and
these verdicts will move when it does.
Every descriptor here is available over the APIs.io API and to AI agents over MCP. Agent Discovery is not yet its own endpoint on the v1 API. Reach it through catalog search and the tag graph, or the MCP server.