Quick Start

Open a file

mark document.md

Or use File > Open (Cmd+O) from within the app.

Open a project folder

mark ~/projects/my-docs/

This opens the folder in the project sidebar. Click any .md file to open it in a tab.

Create a new file

Press Cmd+N or use File > New Tab. The file starts as "Untitled-1" — save with Cmd+S to pick a location.

Basic editing

Mark is a WYSIWYG editor. Just start typing:

• Type # for a heading
• Type - for a bullet list
• Type ``` for a code block
• Type $$ for a KaTeX math block
• Wrap text in **bold** or *italic* — it renders inline

Switch modes

Mode	Shortcut	Description
WYSIWYG	Default	Rich editing with live rendering
Source Code	Cmd+Alt+S	Raw Markdown source
Diff View	Cmd+D	Compare against git HEAD or .before file

Search

• Cmd+F — Find in current document
• Cmd+G / Cmd+Shift+G — Find next / previous
• Cmd+Shift+F — Search across project files
• Enter / Shift+Enter — Next / previous match (when search is open)

Set up your AI agent

Add this to your agent's system prompt or CLAUDE.md:

When you produce a plan, spec, report, or any document longer than ~50 lines,
write it to a .md file and open it in the user's editor:

    open -a Mark <file>.md

The user will read and edit directly in Mark. When you see the file has changed
on disk, read the updated version — the user left feedback inline.