> ## Documentation Index
> Fetch the complete documentation index at: https://docs.magnet.run/llms.txt
> Use this file to discover all available pages before exploring further.

# magnet sandbox-image

> Register custom sandbox images for Magnet sessions.

The `magnet sandbox-image` command group manages custom sandbox images, letting your sessions run in an environment you control.

## magnet sandbox-image register

Register a custom sandbox image from a `docker save` tarball. The CLI uploads the tarball and polls until the image is ready or failed.

```bash theme={null}
docker save my-image:latest -o my-image.tar
magnet sandbox-image register my-image.tar
```

| Option                       | Description                                            |
| ---------------------------- | ------------------------------------------------------ |
| `--poll-interval <duration>` | Interval between status polls (e.g. `2s`, `3s`).       |
| `--timeout <duration>`       | Max time to wait for ready/failed (e.g. `15m`, `20m`). |

## Examples

Register a large image with a longer timeout:

```bash theme={null}
magnet sandbox-image register my-image.tar --timeout 30m --poll-interval 5s
```