What Is Agent2Agent (A2A)? The Protocol Enabling AI Agents to Communicate and Collaborate

A detailed explainer on the Agent2Agent (A2A) protocol covers how it standardizes communication and task delegation between autonomous AI agents across different systems and vendors. A2A provides a structured messaging layer that allows agents to negotiate capabilities, hand off tasks, and share context without requiring custom integration code for every agent-to-agent interaction. For developers building multi-agent systems, this protocol is directly analogous to what HTTP did for web services — a shared contract that reduces integration friction and enables composability at scale. The explainer details the protocol's architecture, message format, and how it differs from simpler tool-calling patterns already common in LLM frameworks. Teams currently building on frameworks like LangGraph, AutoGen, or CrewAI should evaluate A2A compatibility early, as it is positioning itself as an interoperability standard for the agentic ecosystem.