Aperio — Developer Documentation

Aperio is an accessible, cross-platform calendar and task planner. It aims to be fully usable with a screen reader without ever leaving the application/focus mode, while remaining a fast, native desktop app.

This book is for contributors to the application itself. If you instead want to write a plugin (a new calendar/task/contact provider, a sync backend, or a video-conferencing integration), read the Plugin Developer Documentation.

The stack at a glance

• Backend / host: Rust, packaged as a Tauri 2 application (src-tauri, crate name aperio). It owns the SQLite database, the sync engine, the plugin host, and exposes everything to the UI through Tauri commands.
• Frontend: React + TypeScript built with Vite (src/). It is a thin, accessible view layer — all persistence and provider logic live in the backend.
• Core domain + adapters: a Cargo workspace of ~40 crates under crates/ — cal-core (the shared domain types and traits) plus one crate per provider adapter and per plugin.

How to read this book

Chapter	What you’ll find
Getting Started	Prerequisites, cloning, running a dev build, the commands you’ll use daily.
Architecture	How the host, frontend, and plugin system fit together; the data and sync paths.
Contributing	Branching, commits, the accessibility-as-a-gate rule, code style.
Testing	Unit and adapter tests, the accessibility test matrix, CI.
Adapters	Per-provider notes: protocol, auth, quirks, how to test.

The authoritative design spec is DESIGN.md at the repository root. This book distills the parts a contributor needs day to day; when in doubt, DESIGN.md wins.