@vercel/sandbox

Vercel Sandbox

Vercel Sandbox allows you to run arbitrary code in isolated, ephemeral Linux VMs. View the documentation here.

Packages

• @vercel/sandbox (this package) - The SDK for programmatic access to Vercel Sandbox. Source | Documentation
• sandbox - The CLI for interacting with Vercel Sandbox from the command line. Source | Documentation

What is a sandbox?

A sandbox is an isolated Linux system for your experimentation and use. Internally, it is a Firecracker MicroVM that is powered by the same infrastructure that powers 2M+ builds a day at Vercel.

Getting started

To get started using Node.js 22+, create a new project:

mkdir my-sandbox-app && cd my-sandbox-app
npm init -y
vercel link

Pull your authentication token:

vercel env pull

Install the Sandbox SDK:

pnpm i @vercel/sandbox

Create a index.mts file:

import { Sandbox } from "@vercel/sandbox";
import { setTimeout } from "timers/promises";
import { spawn } from "child_process";

async function main() {
  const sandbox = await Sandbox.create({
    source: {
      url: "https://github.com/vercel/sandbox-example-next.git",
      type: "git",
    },
    resources: { vcpus: 4 },
    ports: [3000],
    runtime: "node24",
    name: "vercel-sandbox-example",
  });
  console.log(`Sandbox ${sandbox.name} created`);

  console.log(`Installing dependencies...`);
  const install = await sandbox.runCommand({
    cmd: "npm",
    args: ["install", "--loglevel", "info"],
    stderr: process.stderr,
    stdout: process.stdout,
  });

  if (install.exitCode !== 0) {
    console.log("installing packages failed");
    process.exit(1);
  }

  console.log(`Starting the development server...`);
  await sandbox.runCommand({
    cmd: "npm",
    args: ["run", "dev"],
    stderr: process.stderr,
    stdout: process.stdout,
    detached: true,
  });

  await setTimeout(500);
  spawn("open", [sandbox.domain(3000)]);
}

main().catch(console.error);

Run it:

node --experimental-strip-types --env-file .env.local index.mts

This will:

• Start a sandbox, seeding it with a git repository.
• Install dependencies.
• Run a next dev server
• Open it in your browser

All while streaming logs to your local terminal.

Sandboxes are persistent by default. To resume a sandbox with its previous state:

Create a resume.mts file:

import { Sandbox } from "@vercel/sandbox";
import { setTimeout } from "timers/promises";
import { spawn } from "child_process";

async function main() {
  const sandbox = await Sandbox.get({
    name: "vercel-sandbox-example",
  });
  console.log(`Sandbox ${sandbox.name} resumed`);

  console.log(`Starting the development server...`);
  await sandbox.runCommand({
    cmd: "npm",
    args: ["run", "dev"],
    stderr: process.stderr,
    stdout: process.stdout,
    detached: true,
  });

  await setTimeout(500);
  spawn("open", [sandbox.domain(3000)]);
}

main().catch(console.error);

Run it:

node --experimental-strip-types --env-file .env.local resume.mts

Authentication

Vercel OIDC token

The SDK uses Vercel OIDC tokens to authenticate whenever available. This is the most straightforward and recommended way to authenticate.

When developing locally, you can download a development token to .env.local using vercel env pull. After 12 hours the development token expires, meaning you will have to call vercel env pull again.

In production, Vercel manages token expiration for you.

Access token

If you want to use the SDK from an environment where VERCEL_OIDC_TOKEN is unavailable, you can also authenticate using an access token:

• Go to your team settings, and copy the team ID.
• Go to a project's settings, and copy the project ID.
• Go to your Vercel account settings and create a token. Make sure it is scoped to the team ID from the previous step.

Set your team ID, project ID, and token to the environment variables VERCEL_TEAM_ID, VERCEL_PROJECT_ID, and VERCEL_TOKEN. Then pass these to the create method:

const sandbox = await Sandbox.create({
  teamId: process.env.VERCEL_TEAM_ID!,
  projectId: process.env.VERCEL_PROJECT_ID!,
  token: process.env.VERCEL_TOKEN!,
  source: {
    url: "https://github.com/vercel/sandbox-example-next.git",
    type: "git",
  },
  resources: { vcpus: 4 },
  // Defaults to 5 minutes. The maximum is 5 hours for Pro/Enterprise, and 45 minutes for Hobby.
  timeout: ms("5m"),
  ports: [3000],
  runtime: "node24",
});

Workflow DevKit integration

Sandbox and CommandFinished support serialization with the Workflow DevKit. When a sandbox instance crosses a step boundary the SDK serializes sandbox metadata and routes, then rehydrates synchronously from that snapshot. Deserialized instances lazily recreate an API client using OIDC or environment credentials when needed.

Limitations

• Max resources: 8 vCPUs. You will get 2048 MB of memory per vCPU.
• Sandboxes have a maximum runtime duration of 5 hours for Pro/Enterprise and 45 minutes for Hobby, with a default of 5 minutes. This can be configured using the timeout option of Sandbox.create().

System

The base system is an Amazon Linux 2023 system with the following additional packages installed.

bind-utils
bzip2
findutils
git
gzip
iputils
libicu
libjpeg
libpng
ncurses-libs
openssl
openssl-libs
procps
tar
unzip
which
whois
zstd

• The node24 and node22 images ship Node runtimes under /vercel/runtimes/node{22,24}.
• The python3.13 image ships a Python 3.13 runtime under /vercel/runtimes/python.
• User code is executed as the vercel-sandbox user.
• /vercel/sandbox is writable.

Sudo access

The nodeX and python3.13 images allow users to run commands as root. This can be used to install packages and system tools:

import { Sandbox } from "@vercel/sandbox";

const sandbox = await Sandbox.create();
await sandbox.runCommand({
  cmd: "dnf",
  args: ["install", "-y", "golang"],
  sudo: true,
});

Sandbox runs sudo in the following configuration:

• HOME is set to /root – Executed commands will source root's configuration files (e.g. .gitconfig, .bashrc, etc).
• Environment variables are not reset before executing the command.
• PATH is left unchanged – sudo won't change the value of PATH, so local or project-specific binaries will still be found.

Both these images are based on Amazon Linux 2023. The full package list is available here.

Authors

This library is created by Vercel team members, with contributions from the Open Source Community welcome and highly appreciated.