Glossary¶
Terms used across the Agentic Resource Discovery (ARD) specification and this site.
Agentic resource¶
Any external capability an AI client can call on to perform a task: an agent, MCP server, Skill, API, workflow, AI Catalog entry, or similar. The umbrella term ARD is built around.
Agent Finder¶
A product: one discovery service built on ARD — github.com/agentfinder. It is not the specification itself; many discovery services, named or not, can implement ARD.
AI Catalog¶
The base, artifact-agnostic manifest standard ARD builds on. A publisher hosts an ai-catalog.json file describing its agentic resources. See the AI Catalog Standard.
AI client¶
An orchestrator, agent, or harness — a chatbot, IDE assistant, or automation — that discovers agentic resources through ARD and invokes the ones it selects over their native mechanisms. Also just client.
ARD (Agentic Resource Discovery)¶
The open protocol defined by this specification: how agentic resources describe themselves, how clients ask for them, and how discovery services answer — all before invocation.
Attestation¶
A verifiable claim attached to a catalog entry's trustManifest (e.g. SOC2, HIPAA, GDPR) that a registry or client can fetch and check.
Capability manifest¶
Another name for the ai-catalog.json file a publisher hosts to advertise its agentic resources.
Catalog entry¶
A single agentic resource description within a manifest: its identifier, type, location (url or inline data), and optional metadata.
Discovery service¶
A service that indexes agentic resources and answers search queries (POST /search). The specification's formal term is Agent Registry (or registry); this site uses "discovery service" and "registry" interchangeably. Agent Finder is one such product.
Federation¶
How discovery services draw on each other. A search's federation parameter is auto (the service merges upstream results), referrals (it returns other services for the client to query itself), or none.
MCP, A2A, and Skills¶
Examples of the execution mechanisms and resource types ARD wraps: Model Context Protocol servers, Agent-to-Agent agent cards, and Skills. ARD discovers them; each is invoked over its own mechanism.
Media type¶
The IANA media type in a catalog entry's type field, identifying what an artifact is — e.g. application/mcp-server+json, application/a2a-agent-card+json, application/ai-skill. ARD acts as an envelope over these.
Publisher¶
Whoever hosts an ai-catalog.json describing one or more agentic resources, typically at https://<domain>/.well-known/ai-catalog.json.
Referral¶
An entry in a search response pointing to another discovery service the client may query itself (used with federation: "referrals").
Registry / Agent Registry¶
The specification's term for a discovery service that exposes the standard REST search interface. See Discovery service.
Relevance score¶
The score (0–100) on a search result: a semantic relevance ranking from the discovery service. It is not a trust, compliance, or safety rating.
Representative queries¶
Sample natural-language queries (representativeQueries, 2–5 per entry) that registries use to build semantic search ranking.
Trust manifest¶
Optional verifiable identity and trust metadata on a catalog entry (trustManifest): a cryptographic identity (e.g. did:web, SPIFFE), attestations, provenance, and a detached signature. ARD communicates these signals; it does not itself confer trust.
URN identifier¶
A catalog entry's domain-anchored logical identifier, urn:ai:<publisher>:<namespace>:<agent-name>, where <publisher> is a verifiable domain. It roots identity in DNS and stays stable as infrastructure changes.
Well-known URI¶
The conventional manifest location, https://<domain>/.well-known/ai-catalog.json, where discovery services look for a publisher's catalog.