---
name: vercel-labs/vercel-sandbox
source: https://app.decimal.ai/s/vercel-labs-vercel-sandbox@1/SKILL.md
source_sha256: 92632e2f93ba
---

# Browser Automation with Vercel Sandbox

Run agent-browser + headless Chrome inside ephemeral Vercel Sandbox microVMs. A Linux VM spins up on demand, executes browser commands, and shuts down. Works with any Vercel-deployed framework (Next.js, SvelteKit, Nuxt, Remix, Astro, etc.).

## Dependencies

```bash
pnpm add @agent-browser/sandbox @vercel/sandbox
```

The sandbox VM needs system dependencies for Chromium plus agent-browser itself. The `@agent-browser/sandbox` helpers install them by default for fresh sandboxes and use sandbox snapshots (below) for sub-second startup. Pass `installSystemDependencies: false` only when the sandbox image already provides Chromium's required libraries.

## Core Pattern

```ts
import {
  createAgentBrowserSnapshot,
  runAgentBrowserCommand,
  withAgentBrowserSandbox,
  type VercelSandboxSession,
} from "@agent-browser/sandbox/vercel";

async function withBrowser<T>(
  fn: (sandbox: VercelSandboxSession) => Promise<T>,
): Promise<T> {
  return withAgentBrowserSandbox(fn);
}
```

## Screenshot

The `screenshot --json` command saves to a file and returns the path. Read the file back as base64:

```ts
export async function screenshotUrl(url: string) {
  return withBrowser(async (sandbox) => {
    await runAgentBrowserCommand(sandbox, ["open", url]);

    const titleResult = await runAgentBrowserCommand<{ data?: { title?: string } }>(sandbox, [
      "get", "title",
    ]);
    const title = titleResult.json?.data?.title || url;

    const ssResult = await runAgentBrowserCommand<{ data?: { path?: string } }>(sandbox, [
      "screenshot",
    ]);
    const ssPath = ssResult.json?.data?.path;
    if (!ssPath) throw new Error("Screenshot did not return a file path.");
    const b64Result = await sandbox.runCommand("base64", ["-w", "0", ssPath]);
    const screenshot = (await b64Result.stdout()).trim();

    await runAgentBrowserCommand(sandbox, ["close"], { json: false });

    return { title, screenshot };
  });
}
```

## Accessibility Snapshot

```ts
export async function snapshotUrl(url: string) {
  return withBrowser(async (sandbox) => {
    await runAgentBrowserCommand(sandbox, ["open", url]);

    const titleResult = await runAgentBrowserCommand<{ data?: { title?: string } }>(sandbox, [
      "get", "title",
    ]);
    const title = titleResult.json?.data?.title || url;

    const snapResult = await runAgentBrowserCommand(sandbox, ["snapshot", "-i", "-c"], {
      json: false,
    });

    await runAgentBrowserCommand(sandbox, ["close"], { json: false });

    return { title, snapshot: snapResult.stdout };
  });
}
```

## Multi-Step Workflows

The sandbox persists between commands, so you can run full automation sequences:

```ts
export async function fillAndSubmitForm(url: string, data: Record<string, string>) {
  return withBrowser(async (sandbox) => {
    await runAgentBrowserCommand(sandbox, ["open", url]);

    const snapResult = await runAgentBrowserCommand(sandbox, ["snapshot", "-i"], {
      json: false,
    });
    const snapshot = snapResult.stdout;
    // Parse snapshot to find element refs...

    for (const [ref, value] of Object.entries(data)) {
      await runAgentBrowserCommand(sandbox, ["fill", ref, value]);
    }

    await runAgentBrowserCommand(sandbox, ["click", "@e5"]);
    await runAgentBrowserCommand(sandbox, ["wait", "--load", "networkidle"]);

    const ssResult = await runAgentBrowserCommand<{ data?: { path?: string } }>(sandbox, [
      "screenshot",
    ]);
    const ssPath = ssResult.json?.data?.path;
    if (!ssPath) throw new Error("Screenshot did not return a file path.");
    const b64Result = await sandbox.runCommand("base64", ["-w", "0", ssPath]);
    const screenshot = (await b64Result.stdout()).trim();

    await runAgentBrowserCommand(sandbox, ["close"], { json: false });

    return { screenshot };
  });
}
```

## Sandbox Snapshots (Fast Startup)

A **sandbox snapshot** is a saved VM image of a Vercel Sandbox with system dependencies + agent-browser + Chromium already installed. Think of it like a Docker image: instead of installing dependencies from scratch every time, the sandbox boots from the pre-built image.

This is unrelated to agent-browser's *accessibility snapshot* feature (`agent-browser snapshot`), which dumps a page's accessibility tree. A sandbox snapshot is a Vercel infrastructure concept for fast VM startup.

Without a sandbox snapshot, each run installs system deps + agent-browser + Chromium (~30s). With one, startup is sub-second.

### Creating a sandbox snapshot

The snapshot must include system dependencies (via `dnf`), agent-browser, and Chromium:

```ts
const snapshotId = await createAgentBrowserSnapshot();
```

Run this once, then set the environment variable:

```bash
AGENT_BROWSER_SNAPSHOT_ID=snap_xxxxxxxxxxxx
```

A helper script is available in the demo app:

```bash
npx tsx examples/environments/scripts/create-snapshot.ts
```

Recommended for any production deployment using the Sandbox pattern.

## Authentication

On Vercel deployments, the Sandbox SDK authenticates automatically via OIDC. For local development or explicit control, set:

```bash
VERCEL_TOKEN=<personal-access-token>
VERCEL_TEAM_ID=<team-id>
VERCEL_PROJECT_ID=<project-id>
```

These are spread into `Sandbox.create()` calls. When absent, the SDK falls back to `VERCEL_OIDC_TOKEN` (automatic on Vercel).

## Scheduled Workflows (Cron)

Combine with Vercel Cron Jobs for recurring browser tasks:

```ts
// app/api/cron/route.ts  (or equivalent in your framework)
export async function GET() {
  const result = await withBrowser(async (sandbox) => {
    await sandbox.runCommand("agent-browser", ["open", "https://example.com/pricing"]);
    const snap = await sandbox.runCommand("agent-browser", ["snapshot", "-i", "-c"]);
    await sandbox.runCommand("agent-browser", ["close"]);
    return await snap.stdout();
  });

  // Process results, send alerts, store data...
  return Response.json({ ok: true, snapshot: result });
}
```

```json
// vercel.json
{ "crons": [{ "path": "/api/cron", "schedule": "0 9 * * *" }] }
```

## Environment Variables

| Variable | Required | Description |
|---|---|---|
| `AGENT_BROWSER_SNAPSHOT_ID` | No (but recommended) | Pre-built sandbox snapshot ID for sub-second startup (see above) |
| `VERCEL_TOKEN` | No | Vercel personal access token (for local dev; OIDC is automatic on Vercel) |
| `VERCEL_TEAM_ID` | No | Vercel team ID (for local dev) |
| `VERCEL_PROJECT_ID` | No | Vercel project ID (for local dev) |

## Framework Examples

The pattern works identically across frameworks. The only difference is where you put the server-side code:

| Framework | Server code location |
|---|---|
| Next.js | Server actions, API routes, route handlers |
| SvelteKit | `+page.server.ts`, `+server.ts` |
| Nuxt | `server/api/`, `server/routes/` |
| Remix | `loader`, `action` functions |
| Astro | `.astro` frontmatter, API routes |

## Example

See `examples/environments/` in the agent-browser repo for a working app with the Vercel Sandbox pattern, including a sandbox snapshot creation script, streaming progress UI, and rate limiting.