Open Source  ·  Privacy First

Your Knowledge
Companion

Collect, organise, and act on insights from books, blogs, and podcasts. Open Citadel helps you turn what you read and hear into decisions, ideas, and progress.

Currently in Preview

Core Features

Your Intellectual Den

Timeline

A chronological feed of your highlights and thoughts — filterable, tagged, and always linked to the source.

  • Unified chronological feed
  • Tags & calendar filtering
  • Freeform thoughts

Library

Your centralised home for every EPUB. Sync books from local device folders, track reading progress, mark favourites, and organise collections — all in one place.

  • Folder sync via Android SAF
  • Automatic metadata & covers
  • Collections & archive

EPUB Reader

A focused reading environment for deep immersion. Colour-coded highlights with tags, bookmarking, and built-in Text-to-Speech that follows your reading position — in dark, light, or sepia.

  • TTS follows reading position
  • Colour-coded highlight tagging
  • Bookmarking

Samwell

Interact with your knowledge. Chat with your highlights and surface hidden connections across different sources through privacy first AI.

  • On-device LLM (offline & private)
  • Chat from any highlight
  • Attach books for context

Available Now

Open Source &
Cross-Platform

Built in the open. Every line of code is available to inspect, fork, and build on. Android is live — iOS is on the way.

In an age of digital noise, having a private space to curate your intellectual foundation isn't a luxury — it's a necessity for high-performance thinking.