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

# Storage

> Any S3-compatible service, and what Artbucket keeps in it.

AWS S3, Cloudflare R2, Backblaze B2, Tigris, MinIO, Garage and SeaweedFS all
work. Point the `S3_*` variables at one:

```bash AWS S3 theme={null}
S3_ENDPOINT=https://s3.eu-central-1.amazonaws.com
S3_REGION=eu-central-1
S3_FORCE_PATH_STYLE=false
```

```bash Cloudflare R2 theme={null}
S3_ENDPOINT=https://<account-id>.r2.cloudflarestorage.com
S3_REGION=auto
S3_FORCE_PATH_STYLE=true
```

## What the server sets up

On start, the server creates the bucket when it is missing, allows browser
uploads from `APP_URL` (a CORS rule), and, when the bucket has no lifecycle
rules yet, adds two: `staging/` expires after a day, `renditions/` after 30. A
key that can't change bucket settings (R2's object tokens can't) logs a
warning instead: set those three in the provider's console.

## What is in the bucket

| Prefix                 |                                                                                                            |
| ---------------------- | ---------------------------------------------------------------------------------------------------------- |
| `assets/{sha256}`      | Originals, by the hash of their bytes. Never overwritten; shared by every workspace holding the same bytes |
| `previews/{sha256}`    | Stills for files that aren't images (PDF, PSD, video)                                                      |
| `renditions/`          | Sizes and formats made on request. Expire after 30 days and come back on the next request                  |
| `staging/{workspace}/` | Browser uploads before they are filed. Expire after a day                                                  |

Back up `assets/` and `previews/`. Renditions and staged uploads are
disposable.

## When bytes leave

Deleting an asset keeps it, restorable, for 30 days. Then the sweeper, which
runs in the app every six hours, removes the row, and the original once no
asset in any workspace holds those bytes. Deleting a workspace or an
organization removes its rows at once, and its files at the next sweep. A file
written in the last day is never swept, so an upload in flight is safe.