Agent2Agent (A2A) Protocol

Agent2Agent (A2A) Protocol

An open protocol that enables communication and interoperability between opaque agentic applications.

The Agent2Agent (A2A) protocol tackles a key challenge in the AI field: allowing generative AI agents, built with different frameworks by various companies and running on distinct servers, to communicate and collaborate effectively—as agents, not merely as tools. A2A aims to offer a common language for agents, fostering a more connected, powerful, and innovative AI ecosystem.

With A2A, agents can:

• Discover each other's capabilities.
• Negotiate interaction modalities (text, forms, media).
• Collaborate securely on long-running tasks.
• Operate without revealing their internal state, memory, or tools.

DeepLearning.AI Course

Join this short course on A2A: The Agent2Agent Protocol, created in partnership with Google Cloud and IBM Research, and taught by Holt Skinner, Ivan Nardini, and Sandi Besen.

What you'll learn:

• Make agents A2A-compliant: Expose agents built with frameworks such as Google ADK, LangGraph, or BeeAI as A2A servers.
• Connect agents: Build A2A clients from scratch or use integrations to connect to A2A-compliant agents.
• Orchestrate workflows: Create sequential and hierarchical workflows of A2A-compliant agents.
• Multi-agent systems: Develop a healthcare multi-agent system using different frameworks and observe how A2A enables collaboration.
• A2A and MCP: Discover how A2A complements MCP by enabling agents to collaborate with each other.

Why A2A?

As AI agents become more widespread, their ability to interoperate is essential for building complex, multi-functional applications. A2A aims to:

• Break Down Silos: Link agents across different ecosystems.
• Enable Complex Collaboration: Allow specialized agents to collaborate on tasks that a single agent cannot accomplish alone.
• Promote Open Standards: Encourage a community-driven approach to agent communication, fostering innovation and broad adoption.
• Preserve Opacity: Allow agents to work together without sharing internal memory, proprietary logic, or specific tool implementations, improving security and protecting intellectual property.

Key Features

• Standardized Communication: JSON-RPC 2.0 over HTTP(S).
• Agent Discovery: Through "Agent Cards" detailing capabilities and connection information.
• Flexible Interaction: Supports synchronous request/response, streaming (SSE), and asynchronous push notifications.
• Rich Data Exchange: Supports text, files, and structured JSON data.
• Enterprise-Ready: Designed with security, authentication, and observability as priorities.

Getting Started

• 📚 Explore the Documentation: Visit the Agent2Agent Protocol Documentation Site for a comprehensive overview, the full protocol specification, tutorials, and guides.
• 📝 View the Specification: A2A Protocol Specification
• Use the SDKs:
• 🐍 A2A Python SDK pip install a2a-sdk
• 🐿️ A2A Go SDK go get github.com/a2aproject/a2a-go
• 🧑‍💻 A2A JS SDK npm install @a2a-js/sdk
• ☕️ A2A Java SDK using maven
• 🔷 A2A .NET SDK using NuGet dotnet add package A2A
• 🦀 A2A Rust SDK cargo add a2a-lf
• 🎬 Check out our samples to see A2A in action

Contributing

We welcome community contributions to enhance and grow the A2A protocol!

• Questions & Discussions: Join our GitHub Discussions.
• Issues & Feedback: Report issues or suggest improvements via GitHub Issues.
• Contribution Guide: See our CONTRIBUTING.md for how to contribute.
• Private Feedback: Use this Google Form.
• Partner Program: Google Cloud customers can join our partner program via this form.

What's next

Protocol Enhancements

• Agent Discovery:
• Formalize the inclusion of authorization schemes and optional credentials directly within the AgentCard.
• Agent Collaboration:
• Investigate a QuerySkill() method for dynamic checking of unsupported or unanticipated skills.
• Task Lifecycle & UX:
• Support for dynamic UX negotiation _within_ a task (e.g., agent adding audio/video mid-conversation).
• Client Methods & Transport:
• Explore extending support to client-initiated methods (beyond task management).
• Improvements to streaming reliability and push notification mechanisms.

About

The A2A Protocol is an open source project under the Linux Foundation, contributed by Google. It is licensed under the Apache License 2.0 and is open to contributions from the community.

--- Tranlated By Open Ai Tx | Last indexed: 2026-06-23 ---