A2A
The leading standard for agent-to-agent coordination: agents publish an Agent Card describing their skills, then negotiate and delegate tasks to one another.
Lets independent AI agents on different platforms discover each other, advertise skills, and delegate or negotiate tasks across organizational boundaries.
- name
- A2A
- full_name
- Agent2Agent Protocol
- layer
- interop
- creator
- Google (now under the Linux Foundation)
- status
- production (150+ orgs)
- source
- A2A project / Linux Foundation announcements, 2025–2026 (org count per project communications).
- year
- 2025
- one_liner
- The leading standard for agent-to-agent coordination: agents publish an Agent Card describing their skills, then negotiate and delegate tasks to one another.
- spec_url
- https://a2a-protocol.org
- snippet
GET /.well-known/agent.json → { "name": "...", "skills": [ ... ], "endpoints": { ... } }- abbreviation
- A2A
- also_known_as
Agent2AgentAgent-to-Agent Protocol- canonical_spec_url
- https://a2a-protocol.org
- entity_uri
- https://en.wikipedia.org/wiki/Agent2Agent
- taxonomy_layer
- interop
- sub_layer
- agent-to-agent
- protocol_type
- transport
- central_problem
- Lets independent AI agents on different platforms discover each other, advertise skills, and delegate or negotiate tasks across organizational boundaries.
- maintainer
- A2A project, hosted by the Agentic AI Infrastructure Foundation (AAIF) under the Linux Foundation
- governance_body
- AAIF
- license
- Apache-2.0
- maturity_tag
- production-ready
- current_spec_version
- v1.0
- spec_date
- 2026-04 verify-against-primary-at-build ↗ https://www.linuxfoundation.org/press/a2a-protocol-surpasses-150-organizations-lands-in-major-cloud-platforms-and-sees-enterprise-production-use-in-first-year
- launch_date
- 2025 verify-against-primary-at-build ↗ https://github.com/a2aproject/A2A
- last_verified
- 2026-06-15
- transport
- JSON-RPC / HTTP, with Server-Sent Events for streaming task updates
- core_mechanism
- Each agent publishes an Agent Card at a well-known URL describing its identity, skills, and endpoints; a client agent reads the card and opens a task with the remote agent, exchanging messages and artifacts over the task lifecycle until completion.
- discovery_endpoint
- /.well-known/agent.json (Agent Card)
- settlement_type
- —
- adoption_metric
- 150+ organizations, landed in major cloud platforms, enterprise production use within its first year (April 2026) source
- notable_adopters
{"value":"Google","source":"https://a2a-protocol.org"}{"value":"Major cloud platforms (per LF April 2026 press)","source":"https://www.linuxfoundation.org/press/a2a-protocol-surpasses-150-organizations-lands-in-major-cloud-platforms-and-sees-enterprise-production-use-in-first-year"}- relationships
{"predicate":"complements","target":"mcp","note":"A2A -complements-> MCP (research §2 seed triple): A2A is agent→agent, MCP is agent→tool."}{"predicate":"governed_by","target":"aaif","note":"A2A v1.0 housed by AAIF (research §2)."}{"predicate":"extends","target":"ap2","note":"AP2 is designed as an extension of A2A's task lifecycle for payments."}- ideal_use_case
- Multi-agent systems where agents from different vendors/teams must coordinate and delegate work.
- when_to_use
- When you need agents to talk to OTHER agents — discover skills, hand off tasks, and stream results across trust boundaries.
- when_not_to_use
- When a single agent just needs to call tools or read your site (use MCP or Layer-1 discovery files); A2A's agent-card + task machinery is overhead you don't need.
- code_example
- // Discover a remote agent's capabilities const card = await fetch('https://remote.example/.well-known/agent.json').then(r => r.json()); // card.skills lists what the agent can do; open a task against card.endpoints
- agent_readiness_link
- agent-readiness/a2a
- layer_legacy
- agent
last verified · by Özden Erdinc