Markdown Viewer with cmux

Write a .md file, open it in a panel, and the panel re-renders whenever the file changes on disk. Use it for agent plans and task lists alongside the terminal, documentation and changelogs while working, and notes another process updates progressively.

cmux markdown open plan.md                              # split next to the current terminal
cmux markdown open /path/to/PLAN.md
cmux markdown open design.md --workspace workspace:2    # also --surface, --window

Relative paths resolve against the caller's cwd and ~ expands; the resolved absolute path comes back in the output.

Agent usage

Write the full plan file first, then open it, so the panel never shows a partially written file. After that, overwrite or append freely: each write triggers a re-render, and atomic replacement (editor saves, sed -i, VS Code) is handled.

To instruct coding agents in a project, add to its AGENTS.md:

## Plan Display

When creating a plan or task list, write it to a `.md` file and open it in cmux:

    cmux markdown open plan.md

The panel renders markdown with rich formatting and auto-updates when the file changes.

Rendering

Headings h1-h6 (dividers on h1/h2), fenced code blocks in monospace, inline code with a highlighted background, tables with alternating row colors, nested ordered and unordered lists, blockquotes with a left border, bold/italic/strikethrough, clickable links, horizontal rules, and inline images. Light and dark mode both supported.

Deep-dive references