EiSen

Fast screen capture and annotation for macOS and Windows. Built with Tauri v2, Rust, and SvelteKit. Fully local — no telemetry, no network calls for capture or OCR.

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Install & use

1. Platforms: macOS 11+ and Windows 10/11.
2. Windows (recommended): install EiSen from the Microsoft Store. Store installations receive updates through Microsoft Store. If Store access is unavailable, use the Windows NSIS setup installer .exe from GitHub Releases or eisen.a302.link/download.
3. Windows direct-download note: the GitHub/website NSIS fallback is unsigned. SmartScreen may show Unknown publisher or Windows protected your PC, and managed devices may block it. Verify the published .sha256 sidecar and only continue when you trust the download source. Direct downloads do not include an auto-updater.
4. After you open EiSen there is no Dock / Taskbar icon by default. Look for the EiSen icon in the menu bar / system tray: Capture now, Settings, History, Quit.
5. On macOS, the first capture needs Screen Recording permission (use the hub banner to open System Settings). On Windows, capture works immediately without extra setup.
6. Default hotkey: double-tap Option (⌥⌥) on macOS, PrintScreen (PrtScn) on Windows. If another app already owns PrintScreen, EiSen automatically switches to Ctrl + Shift + 5 and saves that working shortcut; both options are available in Settings.
7. Capture and the overlay use the display under the cursor.
8. Session History lives in memory (last 50 captures). Removing an item from the gallery does not delete files on disk. The gallery is empty after a relaunch; that is expected, not data loss.

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Features

• Capture overlay with an adjustable crop, then Copy, Save, Edit, or OCR.
• Annotation tools: Select, Text, Arrow, Ellipse, Rectangle, Pen, Pen Arrow, Highlight, Blur, Numbered Step, Eraser, Eyedropper.
• Overlay OCR via on-device native OCR (Apple Vision on macOS, Windows Media OCR on Windows — 100% offline, no cloud).
• Undo/Redo, Retina-correct export, and session History from the tray.

Privacy: everything stays on your device. See PRIVACY.md for what is stored on disk.

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Tech stack

• Frontend: Svelte 5 / SvelteKit, TypeScript, Vanilla CSS, Lucide icons, Vitest.
• Backend: Rust and Tauri v2 with platform adapters: macOS AppKit bindings and screencapture, plus Windows xcap and Windows.Media.Ocr.

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Develop

Prerequisites: Node.js v22+ (npm v10+) and Rust 1.75+.

• macOS development: install Xcode Command Line Tools (xcode-select --install) and grant Screen Recording permission for tauri dev.
• Windows development: use the Rust MSVC toolchain with the Windows desktop build tools and SDK.

npm --prefix app install
npm --prefix app run tauri dev

Testing & verification

# Run all checks (Svelte check, Vitest suite, and Rust Clippy)
npm --prefix app run check:all

# Run Rust core tests
cargo test --manifest-path app/src-tauri/Cargo.toml

# Run Rust linter
cargo clippy --manifest-path app/src-tauri/Cargo.toml -- -D warnings

# Run Svelte & TypeScript typecheck
npm --prefix app run check

# Run Frontend unit test suite
npm --prefix app test

Project structure

EiSen/
├── app/
│   ├── src/                  # SvelteKit frontend (routes, editor, overlay)
│   │   ├── lib/              # Geometry math, store, elements, and IPC API
│   │   └── routes/           # Overlay, Editor, Hub, and Settings pages
│   ├── src-tauri/            # Rust backend (Tauri v2 application core)
│   │   ├── src/core/         # Capture orchestrator, output, history
│   │   ├── src/domain/       # Configuration, region geometry, naming
│   │   └── src/platform/     # macOS adapter (Vision / screencapture) & Windows adapter (xcap / WinRT OCR)
│   └── package.json
├── landing/              # Astro site for eisen.a302.link
├── docs/                 # Release runbook
├── scripts/                  # Branding generators and local macOS release
├── LICENSE
└── README.md

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License

MIT.