Shōsai

Shōsai (書斎, "study") is a native desktop ebook reader for PDF and EPUB files. It is written in Rust and uses a GPU-accelerated native interface.

Features

• Read PDF and EPUB files
• Organize a searchable local library
• Resume reading, manage bookmarks and notes, and export bookmarks as Markdown
• Customize font size, line spacing, and light, dark, or sepia reading themes
• Search within documents and use continuous or paginated reading modes

CBZ comic support is planned for a post-launch release.

Installation

Shōsai is currently a work in progress and has not been released yet. Follow development on GitHub or watch the Releases page for its first release.

Build from source

The repository includes a Nix development environment:

nix develop
cargo run --package shosai-app

Alternatively, install Rust 1.94 or newer and the native dependencies required by Iced and PDFium for your platform, then run the same Cargo command.

Development

nix develop
make lint
make test
make check-rfds

make dev stores its isolated database, preferences, and default managed book copies in target/shosai-dev; packaged releases use the platform shosai data directory. Deleting target or running cargo clean therefore also clears the default development state. With the development app closed, make reset removes only the ownership-marked target/shosai-dev state. Production data and books referenced from their current location are preserved. Copied books in an external development managed-library folder are removed only when it contains .shosai-storage-profile with the exact value shosai-development-v1; the folder itself and unrelated files in it are preserved. Reset fails safely if that marker is absent or does not match.

The project is a Cargo workspace:

• crates/shosai-core contains document formats, library storage, and reader logic.
• crates/shosai-app contains the native Iced application.
• website contains the Hugo source for the project website.

Architecture and product proposals follow the Requests for Discussion process. The project roadmap links to the corresponding RFDs.

Website

The public site is a dependency-free Hugo site in website. Run it locally with:

hugo server --source website

See website/README.md for the Cloudflare Pages build configuration.

License

Shōsai is licensed under the Apache License 2.0.