Agent-to-Agent Protocol (A2A)
Definition
A2A is an open protocol through which different AI agent applications can exchange tasks and results.
A2A describes the communication between agent applications. MCP serves to connect tools and data; the protocols can complement each other.
Simply explained
Like a handover between two specialized helpers.
Why it matters in practice
Relevant if separate agent applications are to work together; permissions and result checking must be implemented additionally.
Example from business
Possible example: A research agent transfers verified references via A2A to a writing agent.
Limits and pitfalls
- Unclear responsibilities, unchecked data sharing and lack of results verification; equate A2A with MCP.
Origin & history
Google announced the Agent2Agent protocol on April 9, 2025.
Use in mid-sized companies
- Possible application in medium-sized companies: A research agent transfers verified references to a writing agent.
Frequently asked questions
Is A2A the same as MCP?
No. A2A connects agent applications; MCP binds tools and data. Does A2A guarantee secure results? No, the application requires its own permissions and checks.
Sources
- Ankündigung des Agent2Agent-Protokolls (09.04.2025) · Google, Ankündigung des Agent2Agent-Protokolls (09.04.2025)
- offizielle Protokolldokumentation · A2A, offizielle Protokolldokumentation
Sources checked on 09.10.2026. Editorial application examples are hypothetical; no evidence of real customer results.
Editorially reviewed on: