Show HN: Citadel – a Calibre-compatible eBook management app

Original Article ↗ Hacker News Discussion ↗

A new open source app called Citadel aims to manage eBook libraries while remaining fully compatible with Calibre’s database, but with a modern, cross‑platform UI built using Rust, Tauri, and Svelte. Commenters praise Calibre’s powerful feature set yet widely criticize its unintuitive interface, poor self‑hosting experience, and resistance to architectural changes, seeing Citadel as a potential alternative or complement. The project also reignites a broader debate over whether developers should contribute to established tools or “reinvent the wheel” in public to explore new designs and architectures.

Overview of Citadel

  • New Calibre-compatible ebook management app; aims to keep Calibre’s library format but offer a cleaner, faster, more modern UI.
  • Primarily focused on library management and metadata, not on being a reader or content editor.
  • Designed as a hobby project; backend library that talks to Calibre is factored out for reuse (e.g., potential CLI tools).

Calibre: Power vs. Usability

  • Many commenters praise Calibre’s functionality but find the UI confusing, cluttered, non-standard, or “for enthusiasts, not casuals.”
  • Some users report no problems and find it intuitive for metadata editing, conversion, and syncing.
  • Common pain points: overwhelming options, non-beginner-friendly terminology, lack of “basic view,” desktop-centric design, and poor web/self-hosted management experience.
  • Mixed reports on performance: some run 20k–25k+ books without issues; others say large libraries (e.g., 100GB or 20k+ books) make Calibre unstable or slow. Many argue SQLite itself is unlikely the bottleneck.

Reinventing vs. Improving Existing Tools

  • Debate over whether one should build new apps or contribute to existing open-source projects.
  • One side: most “reinventions” should be private learning projects and contributions should go to established tools.
  • Other side: public reinvention is valuable for learning, experimentation, and avoiding constraints of entrenched codebases; open source effort isn’t strictly zero-sum.

Citadel Features & Roadmap

  • Current/near-term: metadata editing (titles, authors, tags, custom columns), browsing/sorting, Calibre-compatible library access, copying books to folders/devices.
  • Planned/likely: device sync (including Kindle), metadata fetching from online sources, format conversion, possible DRM stripping, plugin/extension system.
  • Custom columns and better filtering/search (including user-defined hierarchies like “Finance.Investing”) are explicitly on the roadmap.
  • Intentionally does not plan an embedded reader or content editor.

Self-Hosting and Integrations

  • Strong interest in a first-class web / self-hosted management experience, which many feel Calibre lacks.
  • Ideas: API/plugins for Bookwyrm integration, content sources, and better multi-user or multi-library handling.

Tech Stack & Development Notes

  • Rust backend + Tauri + Svelte/TypeScript frontend; Bun for scripting and dev tooling.
  • Some initial Linux build issues were acknowledged and then fixed; interest expressed in CI/build automation.
  • Licensed under MIT; name collision with a large finance firm is noted but not deeply discussed.