---
id: a2a-sdk
version: "1.1.2"
license: Apache-2.0
license_treatment: permissive
maintenance: active
---

# a2a-sdk — A2A Python SDK

License: permissive · Maintenance: active · Downloads: 12.4M/mo

## What it is and what it does

The A2A SDK is a Python library for building agentic applications that follow the Agent2Agent (A2A) Protocol specification. It provides a framework for agents to communicate asynchronously over multiple transports—JSON-RPC, HTTP+JSON/REST, and gRPC—with built-in support for modern async Python. The core library is lightweight, but the SDK includes optional integrations for HTTP servers (FastAPI, Starlette), distributed tracing (OpenTelemetry), and SQL persistence (PostgreSQL, MySQL, SQLite), allowing you to compose a deployment stack suited to your needs.

The SDK is maintained actively and supports Python 3.10 through 3.14. It implements the A2A Protocol specification version 1.0 with backward compatibility for 0.3, so agents built with this SDK can interoperate with other A2A-compliant implementations. The 8 core runtime dependencies are all established ecosystem packages, and the install is low-friction.

Use it for:

- Build a microservice-based agent system where agents communicate over HTTP or gRPC following a standardized protocol.
- Implement an agent that exposes itself as a JSON-RPC server for remote clients to invoke its capabilities.
- Create an agentic application with distributed tracing and observability using OpenTelemetry integration.
- Deploy agents with persistent state backed by PostgreSQL, MySQL, or SQLite without writing custom storage logic.
- Develop multi-agent workflows where agents coordinate via the A2A Protocol across different network transports.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

A Python SDK for building agentic applications that communicate via the Agent2Agent (A2A) Protocol, supporting JSON-RPC, HTTP+JSON/REST, and gRPC transports with optional integrations for FastAPI, OpenTelemetry, and SQL databases.

Yes. The SDK is actively maintained, has no known vulnerabilities, uses a permissive Apache 2.0 license, and requires only standard ecosystem dependencies. It is well-suited for anyone building agent-to-agent communication systems that need to follow a standardized protocol. The optional extras allow you to scale from simple local agents to distributed, observable, persistent deployments. Start with the core install and add extras as your use case demands.

## Install

pip install a2a-sdk
uv add a2a-sdk
poetry add a2a-sdk

## Installing a2a-sdk

Before you install: Low friction install with a pure-Python wheel. Active maintenance with a release 23 days old and recent commits. The 8 runtime dependencies are standard ecosystem packages (pydantic, protobuf, httpx, google-api-core), suggesting a stable, well-integrated foundation.

License in practice: Apache 2.0 permissive license allows commercial and private use with minimal restrictions, making it suitable for proprietary agent applications.

Quickstart:

pip install a2a-sdk

from a2a_sdk import Agent

agent = Agent()
# Define agent capabilities and handlers

Requires Python 3.10 or later; the SDK is built on async Python and expects familiarity with asynchronous programming patterns.

Verify before relying:

- Whether the optional integrations (FastAPI, gRPC, OpenTelemetry, SQL drivers) are included in the core install or require separate extras.
- Performance characteristics and throughput limits for typical agentic workloads.
- Maturity and stability of the A2A Protocol specification itself, given the SDK is at version 1.1.2 and the protocol at 1.0.

## Package facts

- License: Apache-2.0 (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 12.4M/month (top 5,000 on PyPI)
- Known vulnerabilities: none known

## Tags

agent to agent protocol python, A2A SDK agentic applications, agent communication framework, async agent server library, A2A protocol implementation, agent2agent python sdk, distributed agent protocol, agent-framework, async-protocol, distributed-agents

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