@sellable/install/bin/sellable-agent-sandbox-init.mjs

One-command installer for Sellable MCP in Claude Code, Codex, and Hermes

#!/usr/bin/env node

import { spawn } from "node:child_process";
import { closeSync, constants, fstatSync, openSync, unlinkSync } from "node:fs";
import { buildRuntimeIdentityLaunchArgs } from "../lib/sellable-agent/runtime-boundary.mjs";

const APP_PATH = "/run/bootstrap/slack-app";
const BOT_PATH = "/run/bootstrap/slack-bot";
const SAFE_ID = /^[A-Za-z0-9_-]{1,128}$/;

function required(name) {
  const value = process.env[name];
  if (typeof value !== "string" || !value) throw new Error(`missing ${name}`);
  return value;
}

function identity(name) {
  const value = required(name);
  if (!/^[1-9][0-9]{0,9}$/.test(value)) throw new Error("runtime identity rejected");
  return value;
}

function inheritedSecret(path) {
  const fd = openSync(path, constants.O_RDONLY | constants.O_NOFOLLOW);
  const info = fstatSync(fd);
  if (!info.isFile() || info.uid !== 0 || info.gid !== 0 || (info.mode & 0o777) !== 0o600 || info.size < 6 || info.size > 4096) {
    closeSync(fd);
    throw new Error("runtime Slack descriptor source rejected");
  }
  unlinkSync(path);
  return fd;
}

async function run() {
  if (process.argv.length !== 2 || process.getuid?.() !== 0 || process.getgid?.() !== 0) {
    throw new Error("sandbox init identity rejected");
  }
  const uid = identity("SELLABLE_AGENT_RUNTIME_UID");
  const gid = identity("SELLABLE_AGENT_RUNTIME_GID");
  const profileId = required("SELLABLE_AGENT_PROFILE_ID");
  if (!SAFE_ID.test(profileId)) throw new Error("sandbox profile rejected");
  const hermes = required("SELLABLE_AGENT_HERMES_EXECUTABLE");
  const setpriv = required("SELLABLE_AGENT_SETPRIV_EXECUTABLE");
  if (!hermes.startsWith("/") || !setpriv.startsWith("/") || setpriv !== "/usr/bin/setpriv") {
    throw new Error("sandbox executable rejected");
  }
  const appFd = inheritedSecret(APP_PATH);
  const botFd = inheritedSecret(BOT_PATH);
  try {
    const args = buildRuntimeIdentityLaunchArgs({
      uid,
      gid,
      profileId,
      hermesExecutablePath: hermes,
    });
    const stdio = Array(10).fill("ignore");
    stdio[1] = "inherit";
    stdio[2] = "inherit";
    stdio[8] = appFd;
    stdio[9] = botFd;
    const child = spawn(setpriv, args, {
      env: process.env,
      shell: false,
      stdio,
    });
    closeSync(appFd);
    closeSync(botFd);
    const forwardTerm = () => { if (!child.killed) child.kill("SIGTERM"); };
    const forwardInt = () => { if (!child.killed) child.kill("SIGINT"); };
    process.once("SIGTERM", forwardTerm);
    process.once("SIGINT", forwardInt);
    process.exitCode = await new Promise((resolveExit, rejectExit) => {
      child.once("error", rejectExit);
      child.once("exit", (code, signal) => resolveExit(code ?? (signal ? 1 : 0)));
    });
  } catch (error) {
    try { closeSync(appFd); } catch {}
    try { closeSync(botFd); } catch {}
    throw error;
  }
}

try {
  await run();
} catch {
  process.stderr.write("sellable-agent sandbox init failed closed\n");
  process.exitCode = 1;
}