{
 "id": "agent-to-agent",
 "name": "Agent2Agent (A2A)",
 "aliases": [
  "Agent2Agent",
  "A2A protocol"
 ],
 "definition_md": "**Agent2Agent (A2A)** is an open protocol—launched by Google in April 2025 and stewarded by the Linux Foundation Agentic AI Foundation (AAIF)—for peer-to-peer communication and task delegation between opaque autonomous agents across organizational boundaries. Where **MCP** connects a host model to tools and data sources (Step 5: Act), **A2A** coordinates multi-turn, potentially long-running **Tasks** between independent agents (Step 6: Coordinate) that discover each other via `/.well-known/agent-card.json`, exchange typed `Part` messages and output `Artifact` objects, and stream updates over SSE or webhook push notifications without exposing internal memory or prompts. Used by: a2a.",
 "step": "coordinate",
 "related_protocols": [
  "a2a",
  "mcp"
 ],
 "sources": [
  {
   "url": "https://a2a-protocol.org/latest/specification/",
   "date": "2026-09-05",
   "label": "VERIFIED"
  },
  {
   "url": "https://aaif.io/blog/a2a-joins-aaif",
   "date": "2026-09-05",
   "label": "VERIFIED"
  }
 ],
 "part_of": null,
 "group": null,
 "url": "https://agenticweb.wiki/terms/agent-to-agent/",
 "okf_url": "https://agenticweb.wiki/okf/terms/agent-to-agent.md",
 "category": "coordinate",
 "type": "term"
}