A2A Adapter

Make any AI agent an A2A Protocol server: a few lines of Python for your own agent, or one command for a local agent like Claude Code or Pi.

a2a-adapter wraps agent CLIs, local agents, workflow engines, and Python agent frameworks behind the A2A (Agent-to-Agent) Protocol. It handles AgentCard generation, JSON-RPC, task lifecycle, and streaming through the official A2A SDK, so your adapter only needs to invoke the underlying agent.

Works with Claude Code, Codex, Pi, OpenClaw, n8n, LangGraph, LangChain, CrewAI, Ollama, Hermes Agent, and custom Python functions.

Two Ways to Use It

	Python SDK	CLI
Use it when	You're writing an agent (or wrapping a framework) and want it to speak A2A	You want to put an existing local agent such as Claude Code or Pi on A2A, without writing code
Install	pip install a2a-adapter in your project's virtualenv	uv tool install a2a-adapter (or pipx install a2a-adapter)
Run	serve_agent(adapter, port=9000) in your code	a2a-adapter claude --port 9010

Both need Python 3.11+ and serve the same A2A server, with an auto-generated Agent Card at /.well-known/agent-card.json.

1. Use It as an SDK

Add A2A support to your own agent code. Install a2a-adapter into your project's virtual environment, with extras for the framework you use:

pip install a2a-adapter              # core
pip install "a2a-adapter[langchain]" # or [crewai], [langgraph], [all]

Wrap your agent in an adapter and serve it:

from a2a_adapter import CallableAdapter, serve_agent

async def my_agent(inputs: dict) -> str:
    return f"Echo: {inputs['message']}"

adapter = CallableAdapter(func=my_agent, name="Echo Agent")
serve_agent(adapter, port=9000)

Your agent is now an A2A server at http://localhost:9000, with its Agent Card at http://localhost:9000/.well-known/agent-card.json. To mount it in an existing ASGI app instead, use to_a2a(adapter).

Supported SDK Adapters

Framework or agent	Adapter	Streaming	Example
Claude Code	ClaudeCodeAdapter	Yes	claude_code_agent.py
Codex	CodexAdapter	No	codex_agent.py
Pi	PiAdapter	Yes	pi_agent.py
OpenClaw	OpenClawAdapter	No	openclaw_agent.py
n8n	N8nAdapter	No	n8n_agent.py
LangGraph	LangGraphAdapter	Yes	langgraph_server.py
LangChain	LangChainAdapter	Yes	langchain_agent.py
CrewAI	CrewAIAdapter	No	crewai_agent.py
Ollama	OllamaAdapter	Yes	ollama_agent.py
Hermes Agent	HermesAdapter	Yes	hermes_agent.py
Python callable	CallableAdapter	Optional	quickstart.py
Custom class	BaseA2AAdapter	Optional	custom_adapter.py

2. Use It as a CLI

Start a classic local agent (Claude Code, Codex, Pi, or OpenClaw) as an A2A server with one command.

Install the CLI as an isolated tool, so the a2a-adapter command lands on your PATH:

uv tool install a2a-adapter    # or: pipx install a2a-adapter