miikun

A simple Markdown editor built for focused writing.

miikun is an Electron + React + TypeScript desktop Markdown editor I built because I wanted a simple place to write. It edits plain .md and .txt files, saves password-protected .mii files, and keeps the UI quiet so the document stays in front.

Use it when you want local files, native desktop shortcuts, tabs, and preview without a workspace or account.

Highlights

• Simple local editing for .md, .txt, and encrypted .mii files
• Multi-tab workflow with dirty-state indicators, tab closing, and drag reordering
• Optional live Markdown preview with tables, checkboxes, footnotes, anchors, definition lists, and Shiki syntax highlighting
• Password prompt for opening and saving .mii files
• Native desktop menus and shortcuts for file, edit, preview, theme, zoom, and window controls
• Light, dark, and system themes, plus an Always on Top mode for reference notes
• Drag-and-drop file opening
• URL paste helper that turns a pasted URL into a Markdown link when the page title can be read

Quick Start

Prerequisites:

• Node.js
• npm

Install dependencies and launch the Electron app:

npm install
npm run electron:serve

The development server is managed by electron-vite and Vite. Browser-only npm run serve / npm run build scripts are not defined because the renderer uses Electron and Node APIs directly.

Everyday Use

Action	Shortcut / Path
New tab	CmdOrCtrl+T or CmdOrCtrl+N
Open file	CmdOrCtrl+O or drag a file into the window
Save	CmdOrCtrl+S
Save as	CmdOrCtrl+Shift+S
Close tab	CmdOrCtrl+W
Next / previous tab	Ctrl+Tab / Ctrl+Shift+Tab
Toggle preview	View -> Toggle Preview Panel
Change theme	View -> Theme
Always on Top	CmdOrCtrl+Shift+T

To create an encrypted note, save the document with the .mii extension and enter a password. Opening that file later asks for the password before the content is loaded.

Development

# Run the Electron app in development
npm run electron:serve

# Build the production desktop app
npm run electron:build

# Build Electron main and renderer output without packaging
npm run prebuild

# Lint JavaScript, TypeScript, and React files
npm run lint

# Type-check TypeScript sources
npm run typecheck

# Check SCSS
npm run lint:scss

# Auto-format SCSS
npm run format:scss

The current production build configuration targets a macOS zip package.

Architecture

miikun keeps the Electron main process small and puts the editor workflow in the React renderer. Third-party libraries are isolated behind adapter modules so the rest of the app depends on app-facing APIs instead of direct library imports.

Key areas:

• src/adapters/ wraps CodeMirror, markdown-it/Shiki, filesystem, encryption, and Electron APIs
• src/services/ owns editor commands, file operations, render sequencing, menus, and tab document state
• src/components/ contains the editor, tab bar, toolbar, drag-and-drop overlay, and password prompt
• src/services/ and src/adapters/ define the boundaries between editor state, file operations, preview rendering, and commands

Contributing

Issues and focused pull requests are welcome. Before opening a PR, run:

npm run lint
npm run lint:scss

There is no automated test suite yet. For changes that affect behavior, also launch the app with npm run electron:serve and verify the edited workflow manually.

License

MIT