---
title: Claude Code
description: Run Anthropic's Claude Code against a project on your host
icon: "/images/recipes/agents/claude-code.svg"
---

This example installs a pinned Claude Code release inside a Node.js microVM and opens it in a project mounted from your host. Claude Code can edit the checkout directly, while its installation, authentication, settings, and sessions stay on the sandbox's root disk.

## Run Claude Code

<Steps>
<Step title="Start Claude Code">

<Tooltip tip="Writable host-directory mounts are local-only. On microsandbox cloud, use the isolated-copy alternative and omit replace-on-create."><span className="msb-badge-local">Local-only <Icon icon="circle-info" size={11} /></span></Tooltip>

Replace `./my-project` with the project directory you want Claude Code to work on:

<CodeGroup>
```sh macOS & Linux
msb run -t --name claude-code-demo --replace \
  --cpus 2 --memory 4G --root-disk 4G \
  --mount-dir ./my-project:/workspace:rw \
  --workdir /workspace \
  node:24-bookworm-slim -- sh -lc '
    apt-get update &&
    apt-get install -y --no-install-recommends ca-certificates git &&
    npm install -g @anthropic-ai/claude-code@2.1.235 &&
    exec claude
  '
```

```powershell Windows
msb run -t --name claude-code-demo --replace `
  --cpus 2 --memory 4G --root-disk 4G `
  --mount-dir ./my-project:/workspace:rw `
  --workdir /workspace `
  node:24-bookworm-slim -- sh -lc '
    apt-get update &&
    apt-get install -y --no-install-recommends ca-certificates git &&
    npm install -g @anthropic-ai/claude-code@2.1.235 &&
    exec claude
  '
```
</CodeGroup>

Choose a terminal theme, then follow the sign-in prompts. If Claude Code cannot open a browser from the microVM, copy the displayed login URL and open it in a browser on your host.

Anthropic recommends its standalone installer for normal host installations. This example uses the pinned npm package for a reproducible sandbox setup; the package installs the same platform-native Claude Code binary.

<Tip>
  For an isolated workspace, or when using microsandbox cloud, replace `--mount-dir ./my-project:/workspace:rw` with `--copy-dir ./my-project:/workspace`.
</Tip>

</Step>

<Step title="Start another session">

After leaving Claude Code, return to the same sandbox and workspace with:

```sh
msb exec -t claude-code-demo -- claude
```

The sandbox root disk retains Claude Code's authentication, configuration, and conversation state between sessions.

</Step>

<Step title="Verify the installation">

Exit the TUI and run:

```sh
msb exec claude-code-demo -- claude --version
```

The pinned example prints `2.1.235 (Claude Code)`.

</Step>

<Step title="Review or export changes">

With the default writable mount, changes are already in the host checkout. Review them inside the sandbox:

```sh
msb exec claude-code-demo -- sh -lc 'cd /workspace && git status --short && git diff --stat && git diff'
```

If you chose the isolated `--copy-dir` alternative, create a patch inside the sandbox:

```sh
msb exec claude-code-demo -- sh -lc 'cd /workspace && git add -N . && git diff --binary > /tmp/claude-code.patch'
```

Copy the patch to the host:

```sh
msb cp claude-code-demo:/tmp/claude-code.patch ./claude-code.patch
```

Check that it applies cleanly before applying it:

```sh
git apply --check ./claude-code.patch
```

</Step>

<Step title="Clean up">

Remove the sandbox:

```sh
msb rm -f claude-code-demo
```

Removing the sandbox also removes its Claude Code credentials, settings, and sessions. Changes made through the default workspace mount remain in the host checkout.

</Step>
</Steps>

## Reference

- [Claude Code setup](https://code.claude.com/docs/en/setup)
- [Claude Code authentication](https://code.claude.com/docs/en/authentication)