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A2A Protocol

RadarOS provides full support for the Agent-to-Agent (A2A) protocol, enabling interoperability between AI agents built on different frameworks.
A2A is an open standard by Google that defines how AI agents communicate with each other via JSON-RPC 2.0 over HTTP. It includes agent discovery, task management, and streaming.

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Capabilities

RadarOS supports both sides of A2A:

A2A Server

Expose your RadarOS agents as A2A-compliant endpoints. Other frameworks (LangGraph, CrewAI, etc.) can discover and call your agents.

A2A Client

Connect to remote A2A agents. Use them as tools, team members, or call them directly.

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How It Works

┌──────────────────┐         ┌──────────────────┐
│  RadarOS Agent    │  A2A    │  Remote Agent     │
│  (Server)         │◄───────►│  (Any Framework)  │
│                   │ HTTP/   │                   │
│  /.well-known/    │  SSE    │  /.well-known/    │
│   agent.json      │         │   agent.json      │
└──────────────────┘         └──────────────────┘
  1. Discovery — Agents publish an Agent Card at /.well-known/agent.json describing their capabilities
  2. Communication — JSON-RPC 2.0 messages over HTTP (message/send) or SSE (message/stream)
  3. Task Management — Each interaction creates a task with lifecycle states (submitted → working → completed)

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Quick Example

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Expose an agent as A2A server

import express from "express";
import { Agent, openai } from "@radaros/core";
import { createA2AServer } from "@radaros/transport";

const app = express();

const agent = new Agent({
  name: "assistant",
  model: openai("gpt-4o"),
  instructions: "You are a helpful assistant.",
});

createA2AServer(app, {
  agents: { assistant: agent },
  provider: { organization: "MyCompany" },
});

app.listen(3001);
// Agent Card: http://localhost:3001/.well-known/agent.json

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Call a remote A2A agent

import { A2ARemoteAgent } from "@radaros/core";

const remote = new A2ARemoteAgent({
  url: "http://localhost:3001",
});

await remote.discover();
const result = await remote.run("Hello!");
console.log(result.text);