AI►Open Source

Google’s A2A Protocol: Building a Common Language for AI Agents

As AI agents become increasingly powerful and diverse, the need for a universal way for them to communicate and collaborate has never been more pressing. Enter A2A (Agent-to-Agent) — an open-source protocol from Google that aims to standardize how AI agents talk to each other, regardless of their underlying frameworks or vendors.

What Is A2A?

A2A is designed to let different AI agents interact over a shared protocol, enabling tasks to be delegated, negotiated, and executed smoothly across systems. Whether you’re building with LangGraph, CrewAI, or something custom, A2A acts like the lingua franca for agents.

Key Components

  • Agent Card: A JSON file (/.well-known/agent.json) describing the agent’s capabilities, endpoints, and authentication requirements — useful for discovery and introspection.
  • A2A Server & Client: Servers expose capabilities via HTTP, while clients (which could be other agents) initiate tasks or communications.
  • Task Lifecycle: From submitted to working, input-required, or completed, A2A tracks the state of work — ideal for long-running or interactive jobs.
  • Messages, Parts & Artifacts: Messages between agents are broken into Parts (text, file, data), and results are returned as Artifacts.

Try It Out

Google has provided several helpful resources:

  • Sample A2A client/server implementations in Python and JavaScript
  • Multi-agent web app demos
  • CLI tools to interact with agents
  • Templates for building A2A-compatible agents in different frameworks

What’s Coming Next?

The roadmap for A2A includes:

  • Richer discovery with built-in auth metadata
  • Skill querying for dynamic capabilities
  • Smarter UX negotiation (e.g., video/audio switching mid-task)
  • More robust streaming and push notification support

Join the Movement

A2A is open for contributions, and the team welcomes feedback via GitHub or a dedicated form. As the AI landscape grows more complex, efforts like A2A are crucial to making intelligent systems interoperable, modular, and collaborative.

GitHub Repository: https://github.com/google/A2A