Quick Start¶

This page shows the fastest host-side path from Python or Node.js.

What Runs Where¶

• Host code runs in your app and uses the isola or isola-core SDK to build templates, create sandboxes, and configure policy.
• Guest code runs inside the sandbox and uses Python sandbox.* modules or JavaScript globals like hostcall(...) and fetch(...).
• For guest-side APIs, see Python Guest API and JavaScript Guest API.

Python SDK¶

Install the SDK:

pip install isola

Run a small Python guest:

import asyncio

from isola import build_template


async def main() -> None:
    template = await build_template("python")

    async with template.create() as sandbox:
        await sandbox.load_script(
            "def add(a, b):\n"
            "    return a + b\n"
        )
        print(await sandbox.run("add", 1, 2))


asyncio.run(main())

Expected output:

3

Use build_template("js") instead to run a JavaScript guest.

If runtime_path is omitted, the SDK downloads and caches the runtime on first use. For hostcalls, mounts, environment variables, and HTTP policy, see Python Host API.

JavaScript / TypeScript SDK¶

Install the SDK:

npm install isola-core

Run a small Python guest from Node.js:

import { buildTemplate } from "isola-core";

const template = await buildTemplate("python");
const sandbox = await template.create();

try {
  await sandbox.start();
  await sandbox.loadScript("def add(a, b):\n    return a + b\n");
  console.log(await sandbox.run("add", [1, 2]));
} finally {
  sandbox.close();
}

Expected output:

3

Use buildTemplate("js") instead to run a JavaScript guest.

If runtimePath is omitted, the SDK downloads and caches the runtime on first use. For hostcalls, mounts, environment variables, and HTTP policy, see Node.js Host API.