{
 "id": "a2a-discovery",
 "name": "A2A protocol, agent discovery",
 "org": "Linux Foundation",
 "kind": "work-item",
 "tier": "core",
 "status": "A2A registers /.well-known/agent-card.json for a single AgentCard; proposals for hosts serving several agents (PR #2240, issues #2276 and #2248) were open on 2026-10-13: PR #2240 and issue #2248 have no comment, and issue #2276 has no comment after 2026-10-02.",
 "status_as_of": "2026-10-13",
 "relevance": "PR #2240 proposes /.well-known/ai-catalog.json as the \"Preferred\" discovery mechanism, and issue #2276 proposes /.well-known/agent-card-list.json for providers serving multiple agents. The documentation (docs/topics/agent-discovery.md on main) says \"The current A2A specification does not prescribe a standard API for curated registries.\"; AI Catalog and Agentic Resource Discovery (ARD) not found in that file (2026-10-03). darrelmiller wrote on issue #1807 (2026-05-12) \"Rather than layering trust information into the AgentCard, we are attempting to use AI Catalog to contain that kind of trust information.\" HTTP Archive custom-metrics PR #176, merged on 2026-10-07, adds a metric for \"/.well-known/agent-card.json\" to track its presence and key metadata.",
 "committed_next": [],
 "boundary": "A maintainer wrote on PR #418 that the A2A working group \"will not be building any kind of registry standard\".",
 "participation": "The author of this map took part in issue #2276 (two comments, 2026-10-02); see Disclosure.",
 "sources": [
  {
   "url": "https://github.com/a2aproject/A2A/pull/2240",
   "archived": "https://web.archive.org/web/20261014052026/https://github.com/a2aproject/A2A/pull/2240",
   "read": "2026-10-02",
   "class": "third-party"
  },
  {
   "url": "https://github.com/a2aproject/A2A/pull/418",
   "archived": "https://web.archive.org/web/20261014052107/https://github.com/a2aproject/A2A/pull/418",
   "read": "2026-10-03",
   "class": "statement"
  },
  {
   "url": "https://github.com/a2aproject/A2A/issues/1807",
   "archived": "https://web.archive.org/web/20261014052152/https://github.com/a2aproject/A2A/issues/1807",
   "read": "2026-10-03",
   "class": "statement"
  },
  {
   "url": "https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md",
   "archived": "https://web.archive.org/web/20261014052231/https://github.com/a2aproject/A2A/blob/main/docs/topics/agent-discovery.md",
   "read": "2026-10-13",
   "class": "normative"
  },
  {
   "url": "https://github.com/HTTPArchive/custom-metrics/pull/176",
   "archived": "https://web.archive.org/web/20261014052308/https://github.com/HTTPArchive/custom-metrics/pull/176",
   "read": "2026-10-08",
   "class": "decision"
  },
  {
   "url": "https://www.linuxfoundation.org/press/linux-foundation-launches-the-agent2agent-protocol-project-to-enable-secure-intelligent-communication-between-ai-agents",
   "archived": "https://web.archive.org/web/20261009075953/https://www.linuxfoundation.org/press/linux-foundation-launches-the-agent2agent-protocol-project-to-enable-secure-intelligent-communication-between-ai-agents",
   "read": "2026-10-03",
   "class": "decision"
  }
 ],
 "overlaps": [
  "ard",
  "lf-ai-catalog",
  "a2a-core"
 ],
 "seams": [
  "S1"
 ],
 "verified": "2026-10-13",
 "evidence": {
  "read": "Repository items read (updated 2026-01-01 to 2026-10-02): discovery threads in full, the rest by keyword search; docs/roadmap.md and agent-discovery.md on main, 2026-10-03.",
  "not_read": "Technical Steering Committee (TSC) minutes and recordings, the diff of PR #2240, the Discord, long identity threads, replies on #2276 after 2026-10-02 (none found: the thread has three comments, the last of 2026-10-02).",
  "not_found": "On 2026-10-13 (main at commit 7c861a5): the state, comment count and last update of PR #2240 and issues #2276 and #2248, the latest release (v1.0.1, 2026-05-28), docs/topics/agent-discovery.md (the quoted sentence present; AI Catalog not found in it) and the history of GOVERNANCE.md (last change 2026-08-25). Not found in roadmap.md: discovery."
 },
 "open_proposals": [
  {
   "what": "PR #2240: /.well-known/ai-catalog.json as the Preferred discovery mechanism (base dev-1.1).",
   "author": "a participant",
   "date": "2026-09-16",
   "state": "open",
   "url": "https://github.com/a2aproject/A2A/pull/2240",
   "archived": "https://web.archive.org/web/20261014052026/https://github.com/a2aproject/A2A/pull/2240"
  },
  {
   "what": "Issue #2276: /.well-known/agent-card-list.json, an array of AgentCards.",
   "author": "a participant",
   "date": "2026-10-01",
   "state": "open",
   "url": "https://github.com/a2aproject/A2A/issues/2276",
   "archived": "https://web.archive.org/web/20261014052408/https://github.com/a2aproject/A2A/issues/2276"
  },
  {
   "what": "Issue #2248: standard multi-agent aggregation path and a ListAgents remote procedure call (RPC).",
   "author": "a participant",
   "date": "2026-09-20",
   "state": "open",
   "url": "https://github.com/a2aproject/A2A/issues/2248",
   "archived": "https://web.archive.org/web/20261014052441/https://github.com/a2aproject/A2A/issues/2248"
  }
 ],
 "url": "https://frmoretto.github.io/agentic-standards-map/entries/a2a-discovery.html",
 "source_url": "https://github.com/frmoretto/agentic-standards-map/blob/a1ae242918902e0768e0e6a79bd2bffc4ac5cfa3/entries/a2a-discovery.yaml",
 "licence": "https://creativecommons.org/licenses/by/4.0/"
}