Agent2Agent (A2A) is a protocol that defines a standard for communication and interaction among agents in complex, multi-agent workflows. It uses Agent Cards to describe the key elements of inter-agent communication, including skill discovery and the specification of transport and security schemes. A2A complements the Model Context Protocol (MCP) by focusing on agent-to-agent communication without exposing internal details such as an agent's state, memory or internal.
The protocol promotes best practices such as an asynchronous-first approach for long-running tasks, streaming responses for incremental updates and secure transport with HTTPS, authentication and authorization. SDKs are available in Python, JavaScript, Java and C# to facilitate rapid adoption. Although relatively new, A2A enables teams to build domain-specific agents that can collaborate to form complex workflows, making it a strong option for such scenarios.
