mdp

A CLI tool that renders markdown files in a native frameless macOS window. Designed for terminal-only agents like Claude Code.

Features

• Native frameless window with rounded corners and shadow
• CommonMark + GFM rendering with syntax highlighting (Chroma)
• KaTeX math and Mermaid diagram support (lazy-loaded)
• Live reload on file changes (fsnotify + polling fallback)
• Multi-window support — each file opens in its own window (re-opening brings existing window to front)
• Table of contents sidebar
• Dark/light/system theme with CSS custom properties
• Vim-inspired keyboard shortcuts
• Pipe from stdin for fire-and-forget previews

Install

Homebrew (macOS)

brew tap mxcoppell/tap
brew install mdp

# Upgrade to latest version
brew update && brew upgrade mdp

Build from source

Requires Go 1.24+ and macOS (CGO + Cocoa).

git clone https://github.com/mxcoppell/mdp.git
cd mdp
make deps    # download vendored JS dependencies (first time only)
make build   # debug build → ./bin/mdp

Usage

# Preview a file with live reload
mdp README.md

# Preview multiple files (each in its own window)
mdp doc1.md doc2.md

# Pipe from stdin
echo "# Hello World" | mdp
cat README.md | mdp

# Options
mdp --theme dark README.md
mdp --toc README.md
mdp --browser README.md    # open in system browser instead

Keyboard Shortcuts

Key	Action
j / k	Scroll down / up
n / p	Next / previous heading
]	Toggle table of contents
Cmd+F	Search
T	Toggle theme
+ / -	Zoom in / out
0	Reset zoom
h	Show shortcuts
Esc	Close window

Build

make build     # debug build with symbols (~21 MB)
make release   # stripped release build (~16 MB)
make test      # run all tests
make clean     # remove build artifacts

License

MIT