# Sandbox SDK adds file permission control

DevFeed: [Sandbox SDK adds file permission control](<https://devfeed.tech/articles/sandbox-sdk-adds-file-permission-control-1082.md>)

Original publisher: [Read original article](<https://vercel.com/changelog/sandbox-sdk-file-permissions>)

Author: Luke Phillips-Sheard

Published: 2026-03-20T00:00:00Z

Content type: release

Language: en

Sources: [Vercel News](<https://devfeed.tech/sources/vercel-news.md>)

Topics: [SDKs](<https://devfeed.tech/topics/sdks.md>), [Vercel](<https://devfeed.tech/topics/vercel.md>), [API](<https://devfeed.tech/topics/api.md>), [chmod](<https://devfeed.tech/topics/chmod.md>), [Script](<https://devfeed.tech/topics/script.md>), [Authorization](<https://devfeed.tech/topics/authorization.md>)

Tags: [api](<https://devfeed.tech/tags/api.md>), [chmod](<https://devfeed.tech/tags/chmod.md>), [documentation](<https://devfeed.tech/tags/documentation.md>), [sandbox](<https://devfeed.tech/tags/sandbox.md>), [sdk](<https://devfeed.tech/tags/sdk.md>), [vercel](<https://devfeed.tech/tags/vercel.md>)

## AI overview

Vercel Sandbox SDK 1.9.0 adds direct file-permission control when writing files through the writeFiles API. A mode property lets developers set permissions in the same operation, avoiding an extra chmod execution round trip.

## Source excerpt

Vercel Sandbox SDK 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. See the documentation to learn more. Read more