Keep audiobooks in S3-compatible storage

Updated October 27, 2026

Berth can store books in any S3-compatible bucket instead of the server's disk. The server keeps the library and decides who may listen; the audio itself can travel from the bucket or a CDN straight to the phones.

Why object storage

A small VPS or a Raspberry Pi does not need a big disk.
Phones download straight from storage, so the server's bandwidth is not the bottleneck.
The database and its backups stay small; with S3 the server can also put a daily database copy into the bucket.

Supported providers

Any S3-compatible service works. The admin has presets that fill in the endpoint and region for: AWS S3, Cloudflare R2, Yandex Cloud, Backblaze B2, Bunny Storage and MinIO. For Cloudflare R2 there is also a wizard that creates the bucket and keys for you.

Connect a bucket

Create a bucket and an access key with read and write access to it in your provider's console.
Add a CORS rule to the bucket: origin is your Berth address, methods GET, HEAD, PUT, headers *. The admin uploads files from the browser straight to the bucket, so this rule is required.
In the Berth admin open the storage settings, add storage, choose “S3 bucket” and pick a preset or fill in the fields yourself.
Fill in name, bucket, endpoint (empty for AWS), region (us-east-1 if empty), access key ID and secret access key. Turn on path-style addresses for MinIO; it is turned on by itself for an IP address or localhost.
Press “Check connection”: Berth writes, reads back and deletes a small test file and checks CORS from your server addresses.
Make the storage the default one: new books go to the default storage.

Keys are stored encrypted with the server key secret.key and are never shown again.

How audio reaches the phones

Without signing, files behind a CDN open by a link that never expires. Their names are SHA-256 hashes and cannot be guessed, but revoking a device does not close links it already has. Bunny CDN token authentication makes links expire after 6 hours.

Mode	How it works	When to use
Direct links (default)	Phones get a signed link to the bucket that lasts 15 minutes	Takes the load off the server
Through the server	The server streams the file; links last 6 hours and stop working at once when a device is revoked	Phones cannot reach the bucket
Through a CDN	Links point to a CDN or a public address of the bucket	Fastest when the bucket has a CDN

Good to know

You can have several storages at once; each book shows which one it is in.
Moving existing books between storages is not available yet: choose the default storage before uploading.
A storage that holds books cannot be deleted. Removing a profile never deletes files in the bucket.

Questions

Does Berth need public access to the bucket?

No. In the default mode the bucket stays private and phones get signed links that expire after 15 minutes.

The check says the bucket does not accept uploads from a browser. What now?

Add the CORS rule: origin is the Berth address, methods GET, HEAD, PUT, headers *. Then run the check again.