sumi

Minimal, filesystem-first EPUB reader. The third in the suika / kaze / sumi triplet: same philosophy, different domain.

• No database. The server doesn't track anything per-user.
• Directory navigation in the web UI (mirrors suika / kaze).
• Cover priority: sibling image (My Book.jpg next to My Book.epub) → folder cover (cover.jpg / folder.jpg / book.jpg) → embedded cover extracted from the EPUB.
• Reader is epub.js rendered client-side. The server only streams the raw .epub.
• Reading position is stored in the browser's localStorage — no server-side state, no SQLite. The downside: bookmarks don't roam across devices.

Layout expected

books/
├── Author Name/
│ ├── Book Title.epub
│ └── Book Title.jpg (optional sibling cover)
└── Another Folder/
├── cover.jpg (folder-wide cover)
└── *.epub

Folder structure is just for browsing; the server doesn't read any of it as metadata.

Configuration

config/config.yml:

app:
port: 8085ui_password: "changeme"jwt_secret: "change-me-in-production"libraries:
- friendly_name: "Books"path: "./books"

Run

go run ./cmd/sumi -config config/config.yml

Or with Docker:

docker build -t sumi .
docker run -p 8085:8085 \
-v ./config:/app/config:ro \
-v /path/to/books:/app/books:ro \
sumi

Open http://localhost:8085, log in with the password from the config. Click into a folder, click an EPUB to read. Arrow keys or click on the left/right zones to turn pages. Esc returns to the library.