Splitmark

A lightweight CLI Markdown editor with live preview.

Description

Splitmark is a terminal-based text editor specifically designed for editing Markdown files. It provides a split-view interface where you can edit your Markdown content on one side (or top) and see a live preview of the rendered output on the other side (or bottom). Perfect for quick edits, note-taking, documentation, or any Markdown workflow in the terminal.

Key highlights:

🎨 Split-view preview - Edit and preview side-by-side or stacked (configurable)
⌨️ Intuitive controls - Familiar keyboard shortcuts for editing, saving, and navigation
⚡ Live rendering - Instant Markdown preview with syntax highlighting
📁 File explorer - Browse and open files when launched without arguments
🎯 Smart file management - Configurable default location with automatic folder creation
🎨 Syntax highlighting - Color-coded Markdown elements in the editor
💾 Configuration system - Customize defaults via ~/.splitmarkrc
☁️ Cloud sync (optional) - Sync files across devices with end-to-end encryption

Screenshots

CLI File Explorer

Browse and select files directly from the terminal

CLI Editor with Live Preview

Split-view editing with real-time markdown preview

Splitmark Cloud - File Management

Manage your files across devices with cloud sync

Web Zen Editor

Distraction-free web editing with the same files from your CLI

Features

Editing

Full text editing with cursor navigation
Syntax highlighting for Markdown (headers, bold, italic, code, links, lists)
Text selection with Shift+Arrow keys
Undo/Redo (Ctrl+Z/Ctrl+Y)
Smart indentation (Tab/Shift+Tab)
Word jumping (Ctrl+Arrow keys)
Line operations (join lines with backspace at start)

Preview

Live rendering with marked and marked-terminal
Synchronized scrolling - Preview follows cursor position
Toggle visibility (Ctrl+P)
Layout switching - Side-by-side ↔ Stacked (Ctrl+L)
Adjustable width - Cycle through 75/25, 50/50, 25/75 ratios (Ctrl+W)

File Management

File explorer - Opens when no file specified
Smart path resolution:
- Simple filenames use default location (~/Documents/Splitmark)
- Nested paths auto-create folders
- Relative paths (./ or ../) use current directory
- Absolute paths work as expected
Config file editing - Open and edit ~/.splitmarkrc with Ctrl+O

Cloud Sync (Optional)

End-to-end encryption - Files encrypted before upload
Cross-device sync - Keep files in sync across multiple computers
Conflict detection - Alerts when files change in multiple places
Secure authentication - JWT-based auth with encrypted credential storage
100% optional - Works perfectly without cloud features

See CLOUD.md for complete cloud sync documentation.

Navigation

Arrow keys - Move cursor up/down/left/right
Ctrl+Arrow - Jump by word
Home/End - Jump to line start/end
Ctrl+Home/End - Jump to file start/end
Page Up/Down - Scroll by page (in file explorer)

Selection

Shift+Arrow - Select text character by character
Ctrl+Shift+Arrow - Select text by word
Delete/Backspace - Delete selected text
Type - Replace selected text

Installation

Global Installation (Recommended)

npm install -g splitmark

Local Development

git clone https://github.com/splitmark/splitmark.git
cd splitmark
npm install
npm link  # Makes 'splitmark' command available globally

Usage

Basic Usage

# Open file explorer (browse files in default location)
splitmark

# Create new file in default location if it doesn't exist
splitmark notes.md

# Create nested file (auto-creates folders)
splitmark projects/myapp/README.md

With Options

# Bottom preview layout
splitmark README.md --layout bottom

# No preview (editor only)
splitmark README.md --no-preview

# Specify layout and width
splitmark notes.md --layout side --width 60

Command-Line Options

Option	Alias	Description	Default
`--layout <side\|bottom>`	`-l`	Preview layout	`side`
`--no-preview`		Disable preview pane	`false`
`--width <number>`	`-w`	Editor width % (side layout only)	`75`
`--help`	`-h`	Show help
`--version`	`-v`	Show version
`--dev`		Use local dev API (localhost:3000)

Cloud Commands

Command	Description
`splitmark login`	Log in to Splitmark Cloud
`splitmark logout`	Log out from cloud
`splitmark sync`	Sync files with cloud
`splitmark cloud:status`	Show cloud sync status
`splitmark cloud:account`	Show account information
`splitmark cloud:enable`	Enable cloud sync
`splitmark cloud:disable`	Disable cloud sync
`splitmark cloud:conflicts`	List sync conflicts

See CLOUD.md for detailed cloud documentation.

Keyboard Shortcuts

File Operations

Shortcut	Action
Ctrl+S	Save file
Ctrl+O	Open config file for editing
Ctrl+X	Exit (warns if unsaved changes)

View Controls

Shortcut	Action
Ctrl+P	Toggle preview visibility
Ctrl+L	Toggle layout (side ↔ bottom)
Ctrl+W	Cycle column width (75/25 → 50/50 → 25/75)

Editing

Shortcut	Action
Ctrl+Z	Undo
Ctrl+Y	Redo
Tab	Indent (2 spaces)
Shift+Tab	Unindent
Enter	New line
Backspace	Delete character (joins lines at start)

Navigation

Shortcut	Action
Arrow keys	Move cursor
Ctrl+Arrow	Jump by word
Home	Jump to line start
End	Jump to line end
Ctrl+Home	Jump to file start
Ctrl+End	Jump to file end

Selection

Shortcut	Action
Shift+Arrow	Select text
Ctrl+Shift+Arrow	Select by word

File Explorer (when no file specified)

Key	Action
↑/↓	Navigate files
Enter	Open file
N	Create new file (prompts for name)
Q or Escape	Exit
Page Up/Down	Scroll list
Home/End	Jump to first/last item

Configuration

Splitmark uses ~/.splitmarkrc for user preferences. On first run, a default configuration is created automatically.

Quick Configuration

Edit your config file directly from Splitmark:

splitmark
# Press Ctrl+O to open config
# Edit settings
# Press Ctrl+S to save
# Press Ctrl+X to return

Configuration Options

{
  "defaultLocation": "~/Documents/Splitmark",
  "layout": "side",
  "showPreview": true,
  "columnWidthRatio": 75,
  "theme": {
    "editor": {
      "background": "#1e1e1e",
      "foreground": "#d4d4d4"
    },
    "syntax": {
      "keyword": "#C586C0",
      "string": "#CE9178"
    }
  }
}

See CONFIG.md for complete documentation.

File Path Resolution

Splitmark intelligently resolves file paths:

# Simple filename → Default location
splitmark meeting.md
# → ~/Documents/Splitmark/meeting.md

# Nested path → Creates folders in default location
splitmark projects/api/docs.md
# → ~/Documents/Splitmark/projects/api/docs.md

# Relative path → Current directory
splitmark ./local.md
# → ./local.md (current working directory)

# Absolute path → Used as-is
splitmark /home/user/notes.md
# → /home/user/notes.md

Platform-Specific Defaults

Windows: Uses OneDrive Documents folder if available
macOS: ~/Documents/Splitmark
Linux: Uses $XDG_DOCUMENTS_DIR or ~/Documents/Splitmark

Development

Running Tests

# Run all tests
npm test

# Run specific test suites
npm run test:unit           # Unit tests
npm run test:integration    # Integration tests
npm run test:components     # Component tests
npm run test:performance    # Performance benchmarks

# Watch mode
npm run test:watch

# Coverage report
npm run test:coverage

Test Coverage

Splitmark includes comprehensive tests:

45 tests across 4 test suites
Unit tests for configuration and utilities
Integration tests for file I/O operations
Component tests for UI rendering
Performance benchmarks for syntax highlighting and file operations

See TESTING.md for detailed documentation.

Development Workflow

# Run with test files
npm run dev dev-files/test.md

# Test different features
npm run dev dev-files/codeblock-test.md  # Code blocks
npm run dev dev-files/tables-test.md     # Tables
npm run dev dev-files/large-file.md      # Performance

Test files are located in dev-files/ - see dev-files/README.md for details.

Project Structure

splitmark/
├── bin/
│   ├── cli.js                # CLI wrapper script
│   └── index.js              # Main entry point with argument parsing
├── src/
│   ├── components/
│   │   ├── Editor.jsx        # Editor wrapper component
│   │   ├── TextBuffer.jsx    # Text buffer with cursor and selection
│   │   ├── Preview.jsx       # Markdown preview component
│   │   ├── StatusBar.jsx     # Status bar with shortcuts
│   │   └── FileExplorer.jsx  # File browser component
│   ├── utils/
│   │   ├── config.js         # Configuration management
│   │   └── syntaxHighlight.js # Markdown syntax highlighting
│   ├── App.jsx               # Main editor application
│   └── FileExplorerApp.jsx   # File explorer wrapper
├── tests/                    # Test suite (45 tests)
│   ├── unit/                 # Unit tests
│   ├── integration/          # Integration tests
│   ├── components/           # Component tests
│   └── performance/          # Performance benchmarks
├── dev-files/                # Development test files
└── docs/
    ├── CONFIG.md             # Configuration documentation
    ├── TESTING.md            # Test suite documentation
    └── IMPLEMENTATION_STATUS.md # Development status

Technology Stack

Ink - React for terminal UIs
React - UI framework
marked - Markdown parser
marked-terminal - Terminal Markdown renderer
chalk - Terminal styling
yargs - CLI argument parsing
Jest - Testing framework

Contributing

Contributions are welcome! To get started:

Fork the repository
Create a feature branch: git checkout -b feature/amazing-feature
Make your changes and add tests
Run tests: npm test
Commit your changes: git commit -m 'Add amazing feature'
Push to the branch: git push origin feature/amazing-feature
Open a Pull Request

Contribution Guidelines

Write tests for new features
Follow the existing code style
Update documentation as needed
Ensure all tests pass before submitting

Performance

Splitmark is optimized for performance:

Syntax highlighting: < 5ms per line, < 100ms for 1000 lines
File I/O: < 100ms for 1MB files, < 500ms for 10MB files
Memory efficient: Consistent performance over time, no memory leaks

See performance benchmarks in TESTING.md.

Requirements

Node.js >= 18.0.0
Terminal with ANSI color support
UTF-8 encoding

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

Built with Ink by Vadim Demedes
Inspired by nano and other terminal text editors
Markdown rendering powered by marked

Support

🐛 Issue Tracker
💬 Discussions

Made with ❤️ for the terminal

Name		Name	Last commit message	Last commit date
Latest commit History 14 Commits
.github/workflows		.github/workflows
bin		bin
dev-files		dev-files
screenshots		screenshots
src		src
tests		tests
.gitignore		.gitignore
.npmignore		.npmignore
.swcrc		.swcrc
CLOUD.md		CLOUD.md
CONFIG.md		CONFIG.md
CONTRIBUTING.md		CONTRIBUTING.md
IMPLEMENTATION_STATUS.md		IMPLEMENTATION_STATUS.md
KNOWN_ISSUES.md		KNOWN_ISSUES.md
LICENSE		LICENSE
README.md		README.md
TESTING.md		TESTING.md
jest.config.js		jest.config.js
package-lock.json		package-lock.json
package.json		package.json
splitmark-icon.png		splitmark-icon.png

License

Splitmark/splitmark

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Splitmark

Description

Screenshots

CLI File Explorer

CLI Editor with Live Preview

Splitmark Cloud - File Management

Web Zen Editor

Features

Editing

Preview

File Management

Cloud Sync (Optional)

Navigation

Selection

Installation

Global Installation (Recommended)

Local Development

Usage

Basic Usage

With Options

Command-Line Options

Cloud Commands

Keyboard Shortcuts

File Operations

View Controls

Editing

Navigation

Selection

File Explorer (when no file specified)

Configuration

Quick Configuration

Configuration Options

File Path Resolution

Platform-Specific Defaults

Development

Running Tests

Test Coverage

Development Workflow

Project Structure

Technology Stack

Contributing

Contribution Guidelines

Performance

Requirements

License

Acknowledgments

Support

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