# Sandbox SDK adds file permission control

**Published:** March 20, 2026 | **Authors:** Luke Phillips\-Sheard

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[Vercel Sandbox SDK](https://www.npmjs.com/package/@vercel/sandbox) `1.9.0` now supports setting file permissions directly when writing files.

By passing a `mode` property to the `writeFiles` API, you can define permissions in a single operation.

This eliminates the need for an additional `chmod` execution round-trip when creating executable scripts or managing access rights inside the sandbox.

```typescript
sandbox.writeFiles([{
  path: 'run.sh',
  content: '#!/bin/bash\necho "ready"',
  mode: 0o755
}]);
```

See the [documentation](https://vercel.com/docs/vercel-sandbox/sdk-reference) to learn more.

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📚 **More updates:** [View all changelog entries](/changelog/sitemap.md) | [Blog](/blog/sitemap.md)