A2A (Agent-to-Agent Protocol)

A2A (Agent-to-Agent Protocol) is an open protocol developed by Google that enables AI agents built on different frameworks and by different vendors to communicate with each other seamlessly. A2A complements Anthropic's Model Context Protocol (MCP) by focusing on agent-to-agent interoperability rather than tool access.

A2A allows agents to discover each other's capabilities through standardized Agent Cards, negotiate communication modalities (text, forms, files, streams), and collaborate on complex tasks. The protocol supports enterprise-grade security, including authentication via OAuth and enterprise identity providers.

A2A represents a critical piece of the emerging agentic infrastructure, enabling multi-agent workflows where specialized agents can delegate subtasks to one another without requiring shared memory or identical frameworks.