{
  "dataset": "glossary",
  "record": {
    "id": "agent-card",
    "term": "Agent Card",
    "category": "identity",
    "short_def": "A JSON document an A2A agent publishes at /.well-known/agent-card.json that advertises its identity, skills, endpoints and authentication.",
    "long_def": "The Agent Card is A2A's discovery primitive — a machine-readable 'business card' hosted at a well-known URI (per RFC 8615) listing the agent's name, description, version, service endpoints, supported interfaces, capabilities (e.g. streaming) and the AgentSkill objects it offers. A client reads the card to decide whether and how to delegate a task to the agent.",
    "see_also": [
      "a2a",
      "agent-identity",
      "agntcy"
    ],
    "etymology_origin": "Defined by the Agent2Agent (A2A) protocol; served at the well-known URI /.well-known/agent-card.json following RFC 8615 'Well-Known Uniform Resource Identifiers'.",
    "related_to": [
      "a2a",
      "agent-identity",
      "agntcy",
      "web-bot-auth"
    ],
    "contrast_with": "Unlike llms.txt or AGENTS.md, which describe a site or repository for ingestion, an Agent Card describes a callable AGENT — its skills, endpoints and auth — so other agents can discover and delegate work to it.",
    "example": "An A2A agent publishes its Agent Card at /.well-known/agent-card.json, listing skills and endpoints so client agents can discover and delegate to it.",
    "source": "https://a2a-protocol.org/dev/topics/agent-discovery/",
    "status": "active",
    "why_it_matters": "The Agent Card is how a service makes itself discoverable and delegable in a multi-agent system; publishing one is the A2A counterpart of having a sitemap for agents.",
    "sameAs": [],
    "bridge_entity": "protocols/interop/a2a",
    "last_verified": "2026-06-15",
    "md_twin": "/glossary/agent-card.md"
  }
}