# Agent2Agent (A2A)

> A protocol for agents to discover and delegate tasks to each other, each publishing an Agent Card of its skills.

_The Agentic Web Lexicon · /glossary/a2a · [JSON](/api/glossary/a2a) · [all The Agentic Web Lexicon](/glossary)_

- **term:** Agent2Agent (A2A)
- **category:** protocols
- **short_def:** A protocol for agents to discover and delegate tasks to each other, each publishing an Agent Card of its skills.
- **long_def:** Where MCP connects an agent to tools, A2A connects agents to other agents. Announced by Google on 9 April 2025 and donated to the Linux Foundation in June 2025 for neutral governance. It defines Agent Cards (capability advertisements), Tasks (the work exchanged) and a transport over HTTP/SSE/JSON-RPC 2.0, with payment extensions (x402, AP2) layered on the task lifecycle.
- **see_also:** mcp, ap2, agentic-commerce
- **etymology_origin:** Announced by Google on 9 April 2025 at Google Cloud Next; released under Apache 2.0 and donated to the Linux Foundation in June 2025, which launched the Agent2Agent Protocol Project.
- **related_to:** mcp, agentic-commerce, agent-identity
- **contrast_with:** Unlike MCP, which connects an agent to tools and data, A2A connects agents to OTHER agents — discovery, task delegation and coordination between peers; the two complement each other.
- **example:** Google announced A2A on 9 April 2025; by April 2026 more than 150 organizations — including Microsoft, AWS, Salesforce, SAP and IBM — supported it.
- **source:** https://en.wikipedia.org/wiki/Agent2Agent
- **status:** active
- **why_it_matters:** A2A is the interoperability layer for multi-agent systems; a site or service that publishes an Agent Card can be discovered and delegated to by other agents.
- **sameAs:** https://en.wikipedia.org/wiki/Agent2Agent
- **bridge_entity:** protocols/interop/a2a
- **last_verified:** 2026-06-15
- **md_twin:** /glossary/a2a.md