Margin

A native Markdown editor, for Omarchy and macOS, where you leave Google Docs-style comments that coding agents read and answer from the command line.

• Markdown is an input mode. Type # and the line becomes a heading; type **bold** and you get bold. The syntax disappears and what stays is a readable document. The file on disk is plain Markdown, and text you didn't touch is never rewritten, so diffs stay small.
• Comments live in the right margin, anchored to the text they're on.
• Changes since the last commit are marked with a bar in the left margin, so you know what to review after an agent's edits.
• Agents use the margin CLI to list threads with file:line locations, reply and resolve. Replies appear in the open editor, and when an agent edits the document, comments stay attached to their text.

Install

Linux

On Omarchy, or any Linux with GTK 4.20+ and libadwaita 1.8+, with Rust:

./install.sh

This installs margin into ~/.local/bin, with a launcher entry and icon.

macOS

On macOS 26, with Homebrew:

brew tap tibbe/margin https://github.com/tibbe/margin
brew install --cask tibbe/margin/margin

This installs Margin into /Applications and the margin CLI onto your PATH.

Or build it, with Xcode 26 and Rust:

xcodebuild -project macos/Margin.xcodeproj -scheme Margin archive -archivePath /tmp/Margin.xcarchive
xcodebuild -exportArchive -archivePath /tmp/Margin.xcarchive -exportPath /tmp/Margin \
  -exportOptionsPlist macos/ExportOptions.plist
ditto /tmp/Margin/Margin.app /Applications/Margin.app
ln -sf /Applications/Margin.app/Contents/Helpers/margin ~/.local/bin/margin

The last line puts the margin CLI on your PATH; any directory on it will do.

Coding agents

Teach your coding agent the workflow:

npx skills add tibbe/margin

License

MIT; see LICENSE. Margin was written by Claude, in Claude Code, directed by Johan Tibell.