Marginal manual
Marginal is a native markdown editor for macOS, Windows, and Linux. One Rust markdown engine drives the editor, the preview, PDF export, and the context handed to the AI. Your files stay plain markdown on disk.
Made for your coding agent
Section titled “Made for your coding agent”The files that steer a coding agent are markdown: CLAUDE.md, AGENTS.md,
rules, skills, sub-agents, commands. Marginal finds them where your agent
looks for them and lists them beside your notes, so you edit the agent’s
instructions with the same preview, AI help, and export as everything else.
Pick the agent in Settings ▸ AI ▸ Coding agent. Claude Code is the default; Codex, Grok Build, OpenCode, Cursor, and Qwen Code are the others, and each has a page here that lists every folder it reads:
| Agent | Instruction file | Manual page |
|---|---|---|
| Claude Code | CLAUDE.md |
Claude Code |
| Codex | AGENTS.md |
Codex |
| Grok Build | AGENTS.md |
Grok Build |
| OpenCode | AGENTS.md |
OpenCode |
| Cursor | AGENTS.md, .cursor/rules |
Cursor |
| Qwen Code | QWEN.md |
Qwen Code |
Start with Your coding agent.
Where to start
Section titled “Where to start”- New to Marginal? Install it, then take a tour of the window.
- Working with a coding agent? Read Your coding agent and the page for yours.
- Want the AI features? Connect an API key, then read about editing with AI.
- Looking something up? The Settings, Keybindings, and Themes pages list everything.
A note on shortcuts
Section titled “A note on shortcuts”Shortcuts in this manual are written the macOS way, with ⌘. On Windows and Linux the same shortcuts use Alt instead, so ⌘K is Alt+K. Ctrl is left to the editor there. The screenshots are from macOS.
Looking for the app itself? See marginal.md.