ag2-a2a

A2A (Agent-to-Agent) integration

Expose an AG2 Agent over the A2A protocol — a standard JSON-RPC / REST / gRPC contract plus a discoverable AgentCard — so other systems can call your agent over the network. The same module also lets an AG2 Agent consume a remote A2A agent by using A2AConfig as the agent's model config.

When to use

• You want an AG2 agent reachable as a standard networked service that non-AG2 A2A clients can call (interop), not just from Python.
• You need a discoverable agent: a published AgentCard at /.well-known/agent-card.json describing the agent's skills, transports, auth, and capabilities.
• You want a choice of transport (JSON-RPC, REST, or gRPC) — possibly several at once from one server.
• You need declared auth schemes (bearer / API key / OAuth2 / OIDC / mTLS), push notifications, or multi-tenancy surfaced on the card.
• Conversely, you want one AG2 agent to call a remote A2A agent as if it were an LLM provider — use A2AConfig as the calling agent's config.

If you only need a web frontend (React/CopilotKit) in front of an agent, use the AG-UI skill instead. If two AG2 agents simply need to talk inside one process/cluster, the AG2 network is the standard multi-agent pattern.

Installation

pip install "ag2[a2a]"

Required. The a2a extra pulls in a2a-sdk (with the HTTP server). gRPC needs the a2a-sdk[grpc] extra in addition. If you cannot run commands, state the exact pip install command.

Public API (from ag2.a2a import ...): A2AConfig, A2AServer, build_card.

60-second recipe — serve an agent over A2A

A2AServer.build_jsonrpc(...) returns a ready-to-serve Starlette ASGI app. Run it directly with uvicorn:

from ag2 import Agent
from ag2.a2a import A2AServer
from ag2.config import OpenAIConfig

agent = Agent(
    name="weather_bot",
    prompt="You answer questions about the weather.",
    config=OpenAIConfig(model="gpt-4o-mini"),
)

server = A2AServer(agent)
# returns a Starlette ASGI app; `url` is the public URL written into the card
app = server.build_jsonrpc(url="http://localhost:8000")