Foldbook Server

Last updated: November 4, 2026

Foldbook Server runs on your NAS, next to your books. It makes them readable by the people you invite, wherever they are, and only shows them what you opened to them. No port to open on your router: it connects to our relay on its own.

Let your AI help

Copy this text and paste it into ChatGPT, Claude or Gemini. It holds everything there is to know: the assistant asks you a few questions about your NAS, then explains each step. If it has access to a terminal, it can even do the install for you.

You're going to help me install Foldbook Server, step by step. Start by asking me the questions you need, one at a time, then guide me. If you have access to a terminal on the machine in question, you may run the install yourself: show me each command before running it.

## What Foldbook Server is
- Foldbook is an Android, iPhone and iPad app that reads comics, manga and books (CBZ, CBR, CB7, PDF, EPUB). Website: https://foldbook.app/en
- Foldbook Server is a Docker container that runs on the NAS (or an always-on computer), next to the books. It lets you lend your library to family and friends, who read it from their own place, on 4G or at work, with their own Foldbook account.
- It connects to the Foldbook relay (wss://relay.foldbook.app) on its own, over an outgoing connection: no port to open on the router, no forwarding to set up.
- It reads books read-only and never changes the files. Nothing is lent until the owner ticks, in the app, the folders they lend. The relay passes pages on without keeping them.

## The image and its settings
- Image: ghcr.io/milrer/foldbook-server:latest (Intel x86_64 and ARM64), public.
- Volume /library (read-only, :ro): the folder that holds the book folders. Each of its subfolders (for example Manga, Comics, Books) can become a lent library. Folders without books (movies, downloads) are never lent by default.
- Volume /data: the server's identity (server.json). Keep it: deleting it means linking again.
- Port 8686: the local status page, which shows the 6-digit link code.
- Optional variable SERVER_NAME: the name suggested when linking (for example the NAS name).

Reference compose file (Synology paths, to adapt):

services:
  foldbook:
    image: ghcr.io/milrer/foldbook-server:latest
    container_name: foldbook-server
    restart: unless-stopped
    ports:
      - "8686:8686"
    environment:
      - SERVER_NAME=MyNAS
    volumes:
      - /volume1/Media:/library:ro
      - /volume1/docker/foldbook:/data

## Questions to ask me first
1. What to install it on: Synology (which DSM version?), QNAP, Unraid, TrueNAS, a Raspberry Pi, a Mac or a PC?
2. Is Docker (or Container Manager on Synology, Container Station on QNAP) already installed?
3. Where are my books: the exact path of the folder holding my comics, manga or book folders?
4. Do you have access to a terminal on this machine, or should you guide me through the interface?

## Steps by machine
- Synology (DSM 7.2 and later): install Container Manager from Package Center. In File Station, create the folder docker/foldbook. In Container Manager › Project › Create: name foldbook-server, path /docker/foldbook (not the books folder), source “Create docker-compose.yml”, paste the file, leave “web portal” unticked, then Done.
- QNAP: Container Station › Applications › Create, paste the file and adapt the paths (/share/…).
- Unraid: the Docker Compose Manager plugin, or a container added by hand with the same volumes and port 8686.
- Linux, Raspberry Pi, Mac or PC with Docker: create a folder, write the file there as compose.yaml with adapted paths, then run “docker compose up -d” in that folder.

## Check
- Open http://MACHINE-ADDRESS:8686 in a browser. The “Foldbook Server” page should show a 6-digit code and “relay connected”.
- The local address is in the NAS network settings, in the router interface, or from “ip addr” / “ipconfig”.

## Link it in the app
1. In Foldbook, sign in (Settings › Account).
2. Settings › Shared library › Link my server, type the code (it changes every 30 minutes).
3. “Share the server reads”: the name of the shared folder mounted on /library (Media for /volume1/Media). Optional; it lets you hide titles from your own libraries.
4. Tick the folders to lend, then invite people: each one gets an 8-character code to type in Settings › Shared library › I got an invitation.

## Troubleshooting
- The :8686 page doesn't open: check that the container is running and read its log. If port 8686 is taken, map another port on the machine side, for example "8687:8686".
- “relay offline”: the machine must be able to reach the internet (HTTPS, port 443) and resolve relay.foldbook.app.
- No folders listed or empty folders: the path mounted on /library is wrong, or the container isn't allowed to read it.
- Expired code: reload the :8686 page.
- Update: the new image has to be downloaded. On Synology, “Build” alone reuses the old image still on the NAS: stop the project, Project › Action › Clean, delete the ghcr.io/milrer/foldbook-server image under Image, then Project › right-click › Build. Elsewhere: docker compose pull, then docker compose up -d. The page on port 8686 then shows the new version. The link, lent folders and guests are kept as long as /data is kept.

Help: https://foldbook.app/en/help · contact: hello@believemy.com

1. Install the container

On a Synology, open Container Manager › Project › Create, pick a folder (for example /volume1/docker/foldbook) and paste this file. Replace /volume1/Media with the folder that holds your comics, manga and books. It is mounted read-only: Foldbook Server never changes your files.

services:
  foldbook:
    image: ghcr.io/milrer/foldbook-server:latest
    container_name: foldbook-server
    restart: unless-stopped
    ports:
      - "8686:8686"
    volumes:
      - /volume1/Media:/library:ro
      - /volume1/docker/foldbook:/data

2. Link it to your account

Open http://your-nas-address:8686 in a browser. The page shows a six-digit code. In Foldbook, tap Settings › Shared library › Link a server, then type the code. In “Share the server reads”, enter the shared folder you mounted (Media for /volume1/Media): that lets you hide titles straight from your libraries. You need a Foldbook account. Then tick the folders you lend: the ones with books are already ticked, and nothing is lent until you confirm.

3. Invite people

In Settings › Shared library, tap your server, then “Invite”. Send the link or code to the person: they open it in Foldbook, with their own account. You then choose their libraries and the titles to hide from them.

Hide titles

In the library, press and hold a cover to start selecting, then tap or slide over other series. “Hide for…” lists the people you invited. The server then refuses those books to that person, even if they know the path.

Without a NAS

On a Mac or PC, Docker Desktop works with the same file. Replace the paths with your books folder and a folder for the settings.

Update Foldbook Server

When a new version comes out, Foldbook tells you: your server’s page shows “Update available”, with what changes. Updating takes two minutes.

Careful: “Build” alone is not enough. Container Manager keeps the old image on the NAS and reuses it. If you stop the project and build it again, you get the same version back. Delete the image first: that is what makes it download the new one.

On a Synology, in Container Manager

Stop the projectProject › foldbook-server › Stop.
Clean the projectProject › foldbook-server › Action › Clean. The stopped container is removed; the project and its file stay. Without this step, the image is still marked “in use” and can’t be deleted.
Delete the imageImage › ghcr.io/milrer/foldbook-server › Delete. Its dot is now grey.
Build the project againProject › foldbook-server › right-click › Build. Since the image is no longer on the NAS, Container Manager downloads the latest version, then starts the server.

To check: http://your-nas-address:8686 shows the new version number, and in Foldbook the “Update available” box is gone.

Nothing to redo in the app: the link, the folders you lend and your guests are kept. They live in the /data folder and in your account, not in the image.

Outside a Synology, in the compose file’s folder:

docker compose pull
docker compose up -d