Overview

The autogen.beta.a2a module exposes any AG2 Agent over the Agent2Agent (A2A) protocol and lets one AG2 agent talk to a remote A2A endpoint as if it were a regular LLM provider. The protocol is transport-agnostic: the same agent can be served over JSON-RPC, HTTP+JSON (REST) or gRPC, and clients pick the binding from the published AgentCard.

When To Use A2A#

Reach for A2A when the agents you need to combine don't live in the same Python process:

• A remote agent owned by a different team (or a different runtime) that you want to call as a tool.
• A network of services that need a vendor-neutral, spec-defined wire format instead of bespoke HTTP APIs.
• A long-running task that should outlive a single client request and be polled / streamed by id.

For in-process multi-agent scenarios — strict turn order, governance, audit trails — see the Multi-Agent Network instead. A2A is the cross-process / cross-host complement, not a replacement.

Mental Model#

   ┌────────────────────────┐                  ┌────────────────────────┐
   │ Local Agent            │                  │ A2AServer              │
   │  config=A2AConfig(...) │  AgentCard       │  wraps an Agent        │
   │                        │  ◀──────────────▶│  + TaskStore           │
   │  send / sendStreaming  │  Task lifecycle  │  + (optional) push     │
   └──────────┬─────────────┘                  └────────────┬───────────┘
              │                                             │
              │  one of: jsonrpc / rest / grpc              │
              └──────────────────  network  ────────────────┘

The server publishes an AgentCard at /.well-known/agent-card.json. Every binding the server supports is listed in card.supported_interfaces; the client reads the card, picks one binding (via prefer=... or the first match) and uses it for the actual message/send, tasks/get and friends. URLs for individual transports are encoded in the card — the client never has to know them up front.

Core Concepts#

Reading Order#

1. Server — expose an existing Agent over A2A.
2. Client — connect to a remote A2A endpoint, multi-turn, client-side tools, as_tool().
3. Tasks & Push — inspect/cancel tasks and manage push-notification webhooks.
4. Advanced — HITL via input_required, streaming reconnect, custom AgentExecutor.

Public API#

Top-level imports — the most commonly used entry points are re-exported from autogen.beta.a2a:

1

from autogen.beta.a2a import A2AConfig, A2AServer, build_card

Sub-modules: