Agent2Agent
The Agent2Agent (A2A) protocol is an open standard, announced by Google in April 2025, that defines how independent AI agents communicate and coordinate with one another across different systems, vendors, and frameworks.
As organizations build more agentic systems, they increasingly need agents built by different teams — and on different platforms — to work together. Without a common protocol, every agent-to-agent integration is bespoke.
A2A addresses this fragmentation by giving agents a standard way to discover each other, exchange messages, and delegate tasks, without sharing internal state or relying on proprietary integrations.
A2A is complementary to the Model Context Protocol (MCP), not a competitor to it. The two solve different problems. MCP connects an agent to its tools and data sources, while A2A connects agents to other agents. An agent harness may combine both — MCP to give each agent its capabilities, and A2A to let those agents collaborate.
Governance
In June 2025, Google transferred A2A to the Linux Foundation for vendor-neutral governance. This mirrors the path taken by MCP, which was likewise moved to a Linux Foundation fund — part of a broader industry effort to reduce fragmentation and vendor lock-in across AI agent ecosystems. IBM subsequently folded its parallel standards, the Agent Communication Protocol (ACP), into A2A.