| name | md-to-html |
| description | Convert Markdown files to self-contained, standalone HTML with GitHub's rendering style. Uses marked for GFM parsing, inlines github-markdown-css, and renders embedded mermaid diagrams via a bundled mermaid.min.js — all with zero external network requests. Requires only Node.js. Use when the user asks to "convert md to html", "render markdown as html", "github-style html from markdown", "render mermaid diagrams in html", or wants an HTML version of a .md file that looks like GitHub. |
GitHub Markdown to HTML
Convert .md files to fully self-contained .html files styled like GitHub's markdown renderer, including rendered mermaid diagrams.
Usage
Run the bundled script:
node ${CLAUDE_PLUGIN_ROOT}/skills/md-to-html/scripts/md-to-html.mjs <input.md> [output.html]
- If no output path is given, writes
<input-name>.html next to the source file.
- Requires Node.js (no other dependencies —
marked is auto-installed on first run).
What it does
- Reads the
.md file
- Parses it with
marked (full GFM spec: tables, strikethrough, autolinks, task lists)
- Detects
```mermaid fenced blocks and rewrites them as <pre class="mermaid">
- Wraps the HTML in
<article class="markdown-body">
- Inlines
github-markdown-css v5.8.1 (auto light/dark theme via prefers-color-scheme)
- Inlines bundled
mermaid.min.js only when the source contains mermaid blocks, and initialises it with a theme matching the user's color scheme
- Writes a single self-contained
.html file (no external CSS/JS, no network requests)
Mermaid
Fenced blocks tagged mermaid are rendered client-side:
```mermaid
graph TD
A[Start] --> B{Decision}
B -->|Yes| C[Do thing]
B -->|No| D[Skip]
```
- The mermaid bundle (~3 MB) is inlined only when at least one mermaid block is present, so plain markdown stays lean.
- Theme follows
prefers-color-scheme; the page reloads on theme change to re-render diagrams.
Tech details
- marked is a fast CommonMark/GFM parser with
gfm: true for full GitHub Flavored Markdown support.
- github-markdown-css is bundled in
assets/github-markdown.min.css for offline use.
- mermaid is bundled as a single UMD-style file in
assets/mermaid.min.js that exposes globalThis.mermaid.
Updating bundled assets
curl -sL "https://cdnjs.cloudflare.com/ajax/libs/github-markdown-css/<VERSION>/github-markdown.min.css" \
-o ${CLAUDE_PLUGIN_ROOT}/skills/md-to-html/assets/github-markdown.min.css
curl -sL "https://cdn.jsdelivr.net/npm/mermaid@<VERSION>/dist/mermaid.min.js" \
-o ${CLAUDE_PLUGIN_ROOT}/skills/md-to-html/assets/mermaid.min.js
