mdrfc

A markdown viewer for the browser and the terminal. RFC style: monospace, 72 columns.

mdrfc README.md          # open in the browser, reloads when you save
mdrfc docs/              # a folder, with a sidebar of every .md file
mdrfc README.md --term   # render in the terminal instead
cat foo.md | mdrfc       # stdin works too

Install

npx mdrfc README.md      # no install
npm install -g mdrfc     # or keep it around

Needs Node 20 or newer. Also runs under Bun and Deno.

Usage

mdrfc [file|dir]          open in the browser
mdrfc [file] --term       render to the terminal
mdrfc                     read markdown from stdin

FLAGS
  -w, --web                 open in the browser (the default)
  -t, --term                render to the terminal instead
  -p, --port <n>            server port (default 2119)
      --no-open             don't open a browser tab
      --no-color            plain text, no ANSI colour
      --no-frontmatter      hide the frontmatter block
      --width <n>           content width in columns (default 72)
      --theme <auto|light|dark>
      --toc <off|top|left|right>   table of contents (default right)
  -h, --help
  -V, --version

Piping picks the terminal for you, so mdrfc x.md | grep foo and mdrfc x.md > out.txt print text instead of opening a tab. So does an SSH session with no display. Pass --web to open a tab anyway.

In the browser

• Live reload — save the file, the page updates and keeps your place.
• Cmd-K — search headings, filenames and text, and jump to the result. The line you picked is highlighted; Esc clears it.
• Table of contents — in the right margin by default, and it follows you down the page. Move it with --toc or the settings panel.
• Heading links — click the # beside a heading to jump there and copy the link. Slugs match GitHub's.
• Images — ![](diagram.png) loads the file from beside the document, and redraws when you save over it.
• Reading position — each document reopens where you left off.
• Settings — the gear button: theme, font, text size, width, table of contents. All remembered in your browser.
• Folders — mdrfc docs/ lists every .md file in a sidebar, grouped by folder. New files appear without a restart.

In the terminal

--term renders RFC-style text, reflowed to 72 columns and paged through less. --no-color drops the colour for plain text. Given a folder, it prints the file tree, then the folder's README.md.

Width

72 columns by default, in both views.

mdrfc README.md --width 80

The settings panel has a width slider (40–200 columns) that overrides it.

Frontmatter

A YAML (---) or TOML (+++) block at the top of the file is shown as a metadata header rather than as body text, and title becomes the page title.

---
title: RFC 9999 — Widget Protocol
author: Riad
tags: [rfc, draft]
---

# Introduction

--no-frontmatter hides the header. Malformed frontmatter is ignored rather than fatal.

Mermaid diagrams

A ```mermaid fence is drawn as a diagram in the browser.

```mermaid
graph TD
  A[Start] --> B{Choice}
  B -->|yes| C[Do it]
  B -->|no| D[Skip]
```

Click a diagram (or press open in its toolbar) to fill the window with it:

| | | |---|---| | drag, arrow keys | pan | | wheel, pinch, + - | zoom | | double-click | zoom in there | | 0 | fit to the window | | Esc, close, click past it | close |

Diagrams follow the page theme, and mermaid ships with mdrfc, so nothing is fetched from the network. If a diagram won't parse, you get the source you wrote and the reason underneath it. The terminal view leaves a mermaid fence as a code block.

Font

Pages are set in Iosevka Brick, which ships with mdrfc, so a machine with no monospace font of its own reads the same as one with a dozen. Pick another family in the settings panel — it searches every font installed on your machine — and that choice sticks.

Contributing

See CONTRIBUTING.md for running from a clone.

License

MIT — see LICENSE.