KeyFit is a privacy-first desktop application that visualizes your real-world typing data, helping you discover your optimal keyboard form factor (45%/60%/75%/TKL, etc.). Designed for programmers, writers, students, and keyboard enthusiasts, KeyFit provides actionable insights into your typing habits—all while keeping your data 100% local.
- Background Monitoring: Auto-starts with OS, accessible from the system tray (Windows) or menu bar (macOS).
- Comprehensive Key Capture: Hooks all key events and aggregates usage per day in a local SQLite database.
- Heatmap Visualization: Interactive, high-performance (60fps) SVG heatmap with automatic dark/light theme switching.
- Flexible Filtering: Filter stats by date range (week/month/all/custom) and by application.
- App Exclusion: Easily exclude specific apps from monitoring via UI.
- Data Management: Reset, import, or export your entire database with a single click.
- Auto Update: Seamless differential updates and version info display.
- Accessibility: Color-blind friendly palettes (Color Brewer presets).
- All data is stored locally—nothing is ever sent externally.
- Data is aggregated by hour, making it impossible to reconstruct individual typed strings.
- No encryption is applied, but privacy is ensured by design.
| Layer | Technology | Notes |
|---|---|---|
| UI | React + TypeScript + MUI v7 | Built-in theme toggling |
| Host | Tauri 2.x (Rust backend + WebView2/WebKit) | Lightweight, native tray integration |
| Key Hook | Rust rdev library |
WH_KEYBOARD_LL (Win) / Event Tap (Mac) |
| Database | SQLite (rusqlite) | No encryption |
| Visualization | d3/visx + SVG | 60fps heatmap rendering |
| Testing | Vitest (UI) / Rust unit tests | Playwright planned for later |
app (
id INTEGER PK,
name TEXT,
bundle_id TEXT
)
key_stat (
ts_day INTEGER ← Unix epoch (rounded)
key_code INTEGER
app_id INTEGER FK→app.id
count INTEGER
PRIMARY KEY (ts_hour, key_code, app_id)
)
excluded_app (
app_id INTEGER PK
)
# Install dependencies
yarn install
# or
npm install
# Start the development server
yarn tauri dev
# or
npm run tauri devyarn tauri build
# or
npm run tauri buildMIT