@rendermark/core

@rendermark/core

Markdown rendering engine — convert Markdown to beautiful HTML documents, PDFs, DOCX, slides, and more.

Installation

npm install @rendermark/core

Quick Start

import { renderMarkdownToHtml } from "@rendermark/core";

const html = await renderMarkdownToHtml({
  title: "My Document",
  markdown: "# Hello World\n\nThis is **RenderMark**.",
  theme: "default",
  showToc: true,
});

// html is a complete, styled HTML document ready to serve or save

API Reference

Rendering

renderMarkdownToHtml(options: RenderOptions): Promise<string>

Render markdown to a full, styled HTML document with CSS, fonts, branding, and table of contents.

const html = await renderMarkdownToHtml({
  title: "Report",
  markdown: content,
  showToc: true,
  theme: "serif",
  template: "report",
  github: { owner: "user", repo: "repo", branch: "main", path: "docs/file.md" },
  sanitize: true, // Strip XSS for public-facing pages
});

markdownToHtmlFragment(markdown: string): Promise<string>

Render markdown to an HTML fragment (no document wrapper). Useful for inline rendering or blog posts.

generateGoogleDocsHtml(title: string, markdown: string): Promise<string>

Generate simplified HTML optimized for Google Docs import, with inline styles and GDocs-compatible formatting.

markdownToDocx(options): Promise<Buffer>

Convert markdown to a DOCX (Word) file buffer.

import { markdownToDocx } from "@rendermark/core";

const buf = await markdownToDocx({
  markdown: content,
  title: "My Document",
  github: { owner: "user", repo: "repo", path: "doc.md" },
});

renderToImage(options: RenderToImageOptions): Promise<void>

Render markdown to a PNG or JPEG screenshot via a callback. Requires a Puppeteer-compatible environment.

renderDiff(options: DiffOptions): string

Generate a visual diff between two markdown versions as a standalone HTML document.

import { renderDiff } from "@rendermark/core";

const html = renderDiff({
  before: oldMarkdown,
  after: newMarkdown,
  mode: "inline", // or "side-by-side"
  title: "Document Changes",
});

markdownToSlides(options: SlideOptions): Promise<string>

Convert markdown into a presentation slide deck. Slides split on --- (horizontal rules) or ## headings.

import { markdownToSlides } from "@rendermark/core";

const html = await markdownToSlides({
  markdown: content,
  title: "My Presentation",
  theme: "dark",
  splitOn: "hr", // or "h2"
});

Frontmatter

parseFrontmatter(markdown: string): { data: FrontmatterData; content: string }

Parse YAML frontmatter from a markdown string. Returns the parsed data and the content without frontmatter.

Themes

getTheme(name: string): string

Get the CSS override for a named theme. Returns an empty string for unknown themes.

listThemes(): string[]

List all available built-in theme names.

isBuiltinTheme(name: string): boolean

Check if a theme name is a built-in theme.

Templates

applyTemplate(name: string, options): string

Apply a named template to markdown content. Templates wrap the markdown with structural elements.

listTemplates(): string[]

List all available built-in template names.

getTemplateDefaultTheme(name: string): string | undefined

Get the default theme associated with a template.

Utilities

resolveGitHubRelativePaths(markdown: string, context?: GitHubContext): string

Resolve relative image/link paths in markdown to absolute GitHub raw URLs.

extractHeadings(markdown: string): TocItem[]

Extract headings (h1–h3) from raw markdown for table of contents generation.

generateTocHtml(headings: TocItem[]): string

Generate an HTML table of contents from extracted headings.

generateSlug(text: string): string

Generate a URL-safe slug from heading text, matching GitHub/rehype-slug conventions.

escapeHtml(str: string): string

HTML-escape a string (&, <, >, ", ').

Unified Pipelines

createProcessor()

Create the full unified processor with all remark/rehype plugins (GFM, math, syntax highlighting, mermaid, callouts, etc.).

createBasicProcessor()

Create a basic processor without syntax highlighting or advanced plugins. Used for Google Docs output.

createSanitizedProcessor()

Create a sanitized processor that strips XSS vectors while preserving classes/ids for styling.

Plugins

These remark/rehype plugins are used internally and exported for advanced usage:

• remarkMermaid — Transform mermaid code blocks into client-side rendered diagrams
• remarkCallouts — Obsidian-style > [!note] callout boxes
• remarkWikiLinks — [[slug]] and [[slug|text]] wiki-style links
• remarkComments — Strip %%hidden%% Obsidian-style comments
• rehypeSourceLines — Add data-source-line attributes for scroll sync

RenderOptions

interface RenderOptions {
  title: string;
  markdown: string;
  showToc?: boolean;        // Include table of contents (default: true)
  github?: GitHubContext;   // GitHub context for resolving relative paths
  docId?: string;           // Document ID for branding links
  theme?: string;           // Theme name
  template?: string;        // Template name
  sanitize?: boolean;       // Use sanitized processor for public pages
}

Themes

Theme	Description
default	Clean, modern with Geist font
dark	Dark background, light text
serif	Traditional serif typography
minimal	Stripped-down, distraction-free

Themes can be set via the theme option or theme frontmatter field.

Templates

Template	Description	Default Theme
report	Formal report with cover page	—
meeting-notes	Meeting notes with attendees	—
memo	Internal memo format	—
letter	Formal letter layout	serif
slides	Presentation slide deck	—
changelog	Version changelog format	—

Templates can be set via the template option or template frontmatter field.

Frontmatter

RenderMark supports YAML frontmatter at the top of markdown files:

---
title: My Document
theme: serif
template: report
toc: true
author: Jane Doe
date: 2025-01-15
custom_field: any value
---

Supported Fields

Field	Type	Description
title	string	Document title
theme	string	Theme name (default, dark, serif, minimal)
template	string	Template name
toc	boolean	Show table of contents
author	string	Author name (used by templates)
date	string	Date (used by templates)

Additional custom fields are passed through and available to templates.

License

MIT