Agent-to-Agent (A2A) Protocol: How Cross-Agent Communication Works in Production

Google launched the A2A protocol in April 2025 as an open standard for communication between intelligent systems. The protocol utilizes HTTP for data transmission and JSON-RPC for structured messaging, facilitating collaboration among smart agents. This design supports asynchronous operations, allowing one agent to send tasks to another while continuing its own work. The A2A protocol aids developers in avoiding custom coding for tool integration, thereby reducing reliance on a single vendor. It aligns with security and authorization patterns used in organizations, simplifying framework replacements without impacting infrastructure.