Google launches A2A, the Agent2Agent protocol

2025-04-09 · Publisher : Google · Domain : Artificial Intelligence

At Google Cloud Next, Google unveils Agent2Agent (A2A), an open protocol that lets AI agents from different vendors discover each other, exchange information and coordinate tasks.

What changes

  • More than 50 partners at launch, including Atlassian, Salesforce, SAP, ServiceNow and Workday.
  • Each agent publishes a JSON "Agent Card" describing its capabilities.
  • The protocol builds on existing standards: HTTP, SSE and JSON-RPC.
  • A2A is meant to complement MCP: MCP connects an agent to its tools, A2A connects agents to one another.
  • On June 23, 2025, Google hands the project over to the Linux Foundation, backed by more than 100 companies.

On April 9, 2025, at Google Cloud Next, Google releases Agent2Agent (A2A), an open protocol designed to make AI agents built on different platforms and by different vendors work together. The starting point: companies deploy specialized agents (HR, support, finance) that cannot talk to each other. ### What happened - **Principle**: a "client" agent delegates a task to a "remote" agent. Both exchange messages and artifacts following a defined task lifecycle, including for tasks lasting several hours. - **Discovery**: each agent exposes a JSON Agent Card describing its skills, making it possible to choose the right agent for a task. - **Technical foundations**: HTTP, Server-Sent Events and JSON-RPC, secure by default, modality-agnostic (text, audio, video). - **Ecosystem**: more than 50 technology partners and service providers at launch, including Atlassian, Box, Cohere, LangChain, MongoDB, PayPal, Salesforce, SAP, ServiceNow and Workday. - **Governance**: on June 23, 2025, Google transfers A2A to the Linux Foundation, with AWS, Cisco, Microsoft, Salesforce, SAP and ServiceNow among the founding members. ### Why it matters A2A complements Anthropic's Model Context Protocol (MCP): MCP standardizes an agent's access to its tools and data, A2A the conversation between agents. With these two building blocks, multi-agent architecture gets an open interoperability foundation, a condition for avoiding lock-in with a single vendor. ### Caveats In 2025, A2A adoption remains markedly slower than MCP's, and the security of agent-to-agent exchanges (authentication, delegation of rights) is still an open issue. ### Key takeaways A2A sets out the principle of agents collaborating across vendor boundaries; for enterprise information systems, it is a building block to watch alongside MCP.

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Tags : IA, Agents, Protocoles, Open Source, Google, Interopérabilité