A2A Python SDK

A Python library for running agentic applications as A2A Servers, following the Agent2Agent (A2A) Protocol.

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Important

Upgrading the SDK from 0.3 to 1.0? See the v0.3 → v1.0 migration guide. For supported A2A spec versions, see Compatibility.

✨ Features

• A2A Protocol Compliant: Build agentic applications that adhere to the Agent2Agent (A2A) Protocol.
• Extensible: Easily add support for different communication protocols and database backends.
• Asynchronous: Built on modern async Python for high performance.
• Optional Integrations: Includes optional support for:
  • HTTP servers (FastAPI, Starlette)
  • gRPC
  • OpenTelemetry for tracing
  • SQL databases (PostgreSQL, MySQL, SQLite)

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🧩 Compatibility

This SDK implements the A2A Protocol Specification 1.0, with compatibility mode for 0.3. See #742 for details on the compatibility scope.

Spec Version	Transport	Client	Server
1.0	JSON-RPC	✅	✅
1.0	HTTP+JSON/REST	✅	✅
1.0	gRPC	✅	✅
0.3 (compat)	JSON-RPC	✅	✅
0.3 (compat)	HTTP+JSON/REST	✅	✅
0.3 (compat)	gRPC	✅	✅

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🚀 Getting Started

Prerequisites

• Python 3.10+
• uv (recommended) or pip

🔧 Installation

Install the core SDK and any desired extras using your preferred package manager.

Feature	uv Command	pip Command
Core SDK	uv add a2a-sdk	pip install a2a-sdk
All Extras	uv add "a2a-sdk[all]"	pip install "a2a-sdk[all]"
HTTP Server	uv add "a2a-sdk[http-server]"	pip install "a2a-sdk[http-server]"
gRPC Support	uv add "a2a-sdk[grpc]"	pip install "a2a-sdk[grpc]"
OpenTelemetry Tracing	uv add "a2a-sdk[telemetry]"	pip install "a2a-sdk[telemetry]"
Encryption	uv add "a2a-sdk[encryption]"	pip install "a2a-sdk[encryption]"
Database Drivers
PostgreSQL	uv add "a2a-sdk[postgresql]"	pip install "a2a-sdk[postgresql]"
MySQL	uv add "a2a-sdk[mysql]"	pip install "a2a-sdk[mysql]"
SQLite	uv add "a2a-sdk[sqlite]"	pip install "a2a-sdk[sqlite]"
All SQL Drivers	uv add "a2a-sdk[sql]"	pip install "a2a-sdk[sql]"

Examples

Helloworld Example

1. Run Remote Agent

   git clone https://github.com/a2aproject/a2a-samples.git
   cd a2a-samples/samples/python/agents/helloworld
   uv run .

2. In another terminal, run the client

   cd a2a-samples/samples/python/agents/helloworld
   uv run test_client.py

3. You can validate your agent using the agent inspector. Follow the instructions at the a2a-inspector repo.

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🌐 More Examples

You can find a variety of more detailed examples in the a2a-samples repository:

• Python Examples
• JavaScript Examples

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🤝 Contributing

Contributions are welcome! Please see the CONTRIBUTING.md file for guidelines on how to get involved.

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📄 License

This project is licensed under the Apache 2.0 License. See the LICENSE file for more details.