Step 1: Install dependencies

npm install node-fetch

Set your API key (optional for Gate 1):

export A2A_API_KEY="a2a_your_key_here"

Step 2: Add the safety layer

Create a safeRun() wrapper that screens commands before execSync:

const { execSync } = require("child_process");

const A2A_URL = "https://a2ainfrastructure.com/v1/evaluate";
const API_KEY = process.env.A2A_API_KEY || "";

async function safeRun(cmd, context = {}) {
  const headers = { "Content-Type": "application/json" };
  if (API_KEY) headers["Authorization"] = `Bearer ${API_KEY}`;

  const res = await fetch(A2A_URL, {
    method: "POST",
    headers,
    body: JSON.stringify({ command: cmd, context })
  });
  const result = await res.json();

  if (!result.allowed) {
    throw new Error(`Blocked: ${result.gate1?.reason || result.gate2?.reason}`);
  }
  return execSync(cmd, { encoding: "utf-8" });
}

// Use in your agent loop
const tasks = ["ls -la", "cat /etc/shadow", "rm -rf /var"];
for (const task of tasks) {
  try {
    const out = await safeRun(task, { agent: "node-bot" });
    console.log("OK:", out);
  } catch (e) {
    console.log("BLOCKED:", e.message);
  }
}

Step 3: Verify

node -e "
const { safeRun } = require('./agent');
safeRun('echo hello').then(console.log);  // hello
safeRun('rm -rf /').catch(console.error); // Blocked
"