--- title: Box Mount product: vercel url: /docs/sandbox/ecosystem/box-mount canonical_url: "https://vercel.com/docs/sandbox/ecosystem/box-mount" last_updated: 2026-09-23 type: how-to prerequisites: - /docs/sandbox/ecosystem - /docs/sandbox related: - /docs/sandbox - /docs/ai-gateway summary: Run a contract review in Vercel Sandbox with Box files and sync the review back to Box. install_vercel_plugin: npx plugins add vercel/vercel-plugin --- # Box Mount [Box Mount](https://developer.box.com/guides/box-mount) syncs a Box folder with a directory in a [Vercel Sandbox](/docs/sandbox). Your agent reads and writes files at that directory. Box Mount syncs those changes to Box while the sandbox runs. ## Related pages > **For AI agents:** Follow these links to understand how this page connects to the rest of the Vercel ecosystem. For the full cross-link map (inbound, outbound, prerequisites, and semantic neighbors), see the .graph.md link below. - [How to give agents persistent storage with Vercel Drives](https://vercel.com/kb/guide/persistent-storage-with-vercel-drives) — Give AI SDK and TanStack AI agents persistent storage with Vercel Drives so they can save and reuse research notes acros - [Vercel Sandbox](https://eve.dev/docs/sandbox/vercel) — Create persistent sandboxes on Vercel, from a prepared snapshot when the environment has build-time setup. - [Running OpenCode securely with the Vercel Sandbox](https://vercel.com/kb/guide/running-opencode-securely-with-the-vercel-sandbox) — Run OpenCode in an isolated Vercel Sandbox MicroVM with controlled egress, using the SDK to restrict network access so t - [Using Vercel Sandbox to run Claude’s Agent SDK](https://vercel.com/kb/guide/using-vercel-sandbox-claude-agent-sdk) — Learn how to deploy Claude's Agent SDK in Vercel Sandbox for secure and isolated execution of AI-powered code generation - [Understanding Sandboxes](https://vercel.com/docs/sandbox/concepts) — Learn how Vercel Sandboxes provide on-demand, isolated compute environments for running untrusted code, testing applicat - [Drives](https://vercel.com/docs/sandbox/concepts/drives) — Persistent storage that can be mounted into sandboxes and shared across runs. - [vercel sandbox](https://vercel.com/docs/cli/sandbox) — Interact with Vercel Sandbox from the Vercel CLI: list, create, connect, exec, copy, stop, and snapshot sandboxes from y - [Persistence](https://vercel.com/docs/sandbox/concepts/persistent-sandboxes) — Sandboxes automatically save their filesystem state when stopped and restore it when resumed. No manual snapshot managem Full cross-link map for this page: [/docs/sandbox/ecosystem/box-mount.graph.md](/docs/sandbox/ecosystem/box-mount.graph.md) > **💡 Note:** Box Mount is in private preview. [Request access from Box](https://bit.ly/box-mount-preview) > to get the Linux binary. ## Run the contract review example The [Vercel Box Mount example](https://github.com/vercel-labs/vercel-box-mount) reviews a synthetic contract with [AI Gateway](/docs/ai-gateway) inside a sandbox. It writes `Reviewed/Acme-MSA-review.md` to the Box folder and checks that the file is still there after the sandbox is deleted. Before you start, get a Box developer token with file read and write access, create an empty Box folder, and note its folder ID. You also need the Box Mount 0.5.0 Linux x86\_64 archive, an AI Gateway API key, and a Vercel project with Sandbox access. The example requires Node.js 20 or later. Clone the example and copy its Vercel configuration template: ```bash git clone https://github.com/vercel-labs/vercel-box-mount.git cd vercel-box-mount npm ci cp .env.vercel.example .env ``` Set `AI_GATEWAY_API_KEY`, `BOX_ACCESS_TOKEN`, `BOX_FOLDER_ID`, and `BOX_MOUNT_ARCHIVE` in `.env`. The archive value is the absolute path to the downloaded Box Mount file. Set `VERCEL_TOKEN`, `VERCEL_TEAM_ID`, and `VERCEL_PROJECT_ID` for your Vercel project, or use `VERCEL_OIDC_TOKEN`. The template already selects Vercel Sandbox. Keep `.env` and the archive out of git. The [example setup guide](https://github.com/vercel-labs/vercel-box-mount/blob/main/docs/vercel-setup.md) has the full configuration and recovery steps. Run the example: ```bash npm run doctor npm run seed npm run demo npm run status npm run teardown ``` `doctor` checks the setup and verifies that the agent user cannot read the Box credentials. `seed` uploads the synthetic contract and playbook to the empty Box folder. `demo` creates the review in the sandbox and syncs it to Box. `status` shows the running sandbox. Check the review in Box, then run `teardown` before the example's 30-minute session ends. Teardown unmounts the folder, verifies the review in Box, and removes the sandbox. If sync or unmount fails, follow the [recovery steps](https://github.com/vercel-labs/vercel-box-mount/blob/main/docs/vercel-setup.md#lifecycle-and-credentials) before stopping the sandbox. Stopping it first can discard files that have not reached Box. ## Before using Box Mount in your own agent The example runs Box Mount and the agent as separate sandbox users. Box Mount holds the Box credentials; the agent can access the shared folder. Read the [implementation](https://github.com/vercel-labs/vercel-box-mount/blob/main/src/vercel.ts) and [Box's setup guide](https://developer.box.com/guides/box-mount) before adapting the mount to another workload. Box developer tokens expire after 60 minutes and cannot be refreshed. Box Mount also has [preview workload and file-save limits](https://developer.box.com/guides/box-mount/#known-limitations). Check those limits before using tools that replace files through an atomic rename. --- [View full sitemap](/docs/sitemap) If you find anything wrong or missing or can't find something, submit feedback by reading https://vercel.com/feedback.md to improve Vercel.