venomx-pdf-cli

Convert Markdown files into a polished, print-ready PDF with one command. Built-in themes, syntax highlighting, optional Table of Contents, and custom CSS keep exports consistent and offline-friendly.

Features

• Merge one or many .md files into a single PDF (order preserved)
• Built-in themes: default, dark, clean
• Syntax highlighting for code blocks (highlight.js)
• Optional Table of Contents (--toc) generated from headings
• Custom document title (--title) and custom CSS overrides (--css)
• Works fully offline once dependencies are installed; suited for CI/CD pipelines

Quick start

npm install
npm run build
node dist/index.js README.md -o README.pdf --theme dark --toc --title "My Doc"

CLI usage

vpdf <files...> [options]
# alias
venomx <files...> [options]

Options:

• -o, --output <file> Output PDF path (default: first file name with .pdf)
• --theme <name> Theme to apply (default, dark, clean)
• --theme <path> Provide a CSS file as the theme
• --toc Add a Table of Contents based on document headings
• --title <title> Override the document title
• --css <file> Append a custom CSS file after the chosen theme
• --html-only Emit HTML only (skip PDF generation)
• --no-sandbox Launch Chromium without sandboxing (useful in restricted CI)
• --splash Show a welcome splash screen and exit (can be run without files)

Examples:

# Merge multiple files with a TOC and dark theme
vpdf intro.md api.md guide.md --toc --theme dark -o docs.pdf
# same with alias
venomx intro.md api.md guide.md --toc --theme dark -o docs.pdf

# Add custom title and CSS overrides
vpdf README.md --title "Project Handbook" --css styles/custom.css
# alias
venomx README.md --title "Project Handbook" --css styles/custom.css

Custom CSS tips

Your CSS is appended after the selected theme. A simple override:

:root {
  --accent: #f97316;
  --font-body: "Georgia", serif;
}
.doc-title { text-align: center; }

Development

• npm run dev Run the CLI with ts-node
• npm run build Emit compiled files to dist/
• npm run clean Remove the build output
• npm test Build then run a fast HTML snapshot test (no Chromium launch)

Functionality + Logic Flow

System functionality

• Markdown → PDF conversion: merge one or many .md files into a single PDF with consistent formatting.
• Theme support: built-in default, dark, clean plus optional custom CSS via --css ./my-style.css.
• Table of Contents: auto-generates clickable links from document headings when --toc is provided.
• Syntax highlighting: code blocks are highlighted with highlight.js.
• Output customization: -o output.pdf, --title "My Project Docs", A4 page size by default.
• CLI execution: vpdf input.md (installed) or npx venomx-pdf-cli.

Internal logic flow

1. Parse CLI inputs with commander; validate file paths, output name, theme name, flags (--toc, --title, --css, --no-sandbox).
2. Read Markdown files with fs.readFile; if multiple, preserve order and label sections.
3. Convert Markdown → HTML via markdown-it (HTML enabled, linkify, typographer) + highlight.js; collect heading text/levels.
4. Generate TOC when enabled: normalize heading levels (H1–H6) and build anchor links.
5. Load theme CSS: apply built-in theme and append custom CSS if provided.
6. Build final HTML document: inject styles, TOC (if any), and rendered sections.
7. Render PDF with Puppeteer: headless Chromium loads HTML and exports PDF (printBackground, A4).
8. Save and finish: write PDF to disk and log ✅ PDF created: <path>.

Core logic pseudo-code

function runConversion(options) {
  const files = resolveFiles(options.input);
  const slugCounts = new Map();
  const md = createMarkdownRenderer(slugCounts);

  const sections = files.map((file) => {
    const content = readFile(file);
    const { html, headings } = renderMarkdown(md, content, slugCounts);
    return { html, headings, label: basename(file) };
  });

  const toc = options.toc ? generateToc(flattenHeadings(sections)) : "";
  const themeCss = loadTheme(options.theme) + loadCustomCss(options.css);
  const html = wrapHtml({ title: options.title, toc, sections, themeCss });

  exportPdf(html, options.output, options.noSandbox);
}