A2A Protocol

The open standard for Agent-to-Agent communication

A2A Protocol Flow

Agent A

Send Connection Request

Initialize secure communication channel

Request Capabilities

Query available functions and services

Propose Task

Submit task requirements and parameters

Process Results

Handle task completion and outcomes

Agent B

Accept Connection

Establish secure communication link

Share Capabilities

Provide available service information

Accept Task

Confirm task execution readiness

Return Results

Deliver task execution results

A2A Protocol enables standardized communication and task execution between autonomous agents

Core Components

Agent Card

Standardized description card defining agent capabilities and functions.

Task

Tasks exchanged between agents with clear objectives and requirements.

Message

Communication unit between agents supporting various formats.

Part

Building blocks of messages, including text, images, code, or structured data.

Artifact

Persistent outputs of agent collaboration, such as documents or datasets.

Implementations

A2A Protocol implementations in various programming languages.

Latest Updates

March 15, 2025

A2A Protocol v1.0 Released

Google officially releases the first stable version of A2A Protocol with complete specifications and reference implementations.

April 2, 2025

Python A2A Client Library 0.9.0

New Python client library with simplified API and rich examples for quick integration.

April 10, 2025

A2A Community Contribution Guide

Learn how to contribute to the A2A ecosystem, submit new implementations, or improve existing code.

Start Building Intelligent Agent Systems with A2A

Join the developer community and build interoperable AI agent ecosystems using standardized protocols