Build a Node.js Content Pipeline

Choose the result your application needs: an HTML string, UTF-8 bytes, or HTML with document metadata. All operations are synchronous.

Get HTML, front matter, and headings

import { transform } from "ferromark";

const source =
  "---\ntitle: Installation\n---\n# Installation\n\nRun `npm install ferromark@2.0.0-rc.1`.";
const page = transform(source, { frontMatter: true });

console.log(page.frontMatter); // 'title: Installation\n'
console.log(page.headings[0]);
// { level: 1, id: 'installation', text: 'Installation' }
console.log(page.html);

Front-matter extraction is opt-in, including for transform(). The result is raw text between --- or +++ delimiters; parse it with the YAML or TOML library your application uses. Headings arrive in document order for a table of contents. See the shared pipeline concepts for output responsibilities.

Reuse a renderer for a collection

import { Renderer } from "ferromark";

const renderer = new Renderer({ headingIds: true, footnotes: true });
const pages = ["# First page", "# Next page"].map((source) => renderer.toHtml(source));
console.log(pages);

Options are fixed at construction. Keep one renderer per worker. It retains parser scratch allocations while resetting headings, references, and footnotes between documents. Each call returns its own HTML. Renderer provides toHtml() and toHtmlBuffer(); use transform() when you need metadata.

Send UTF-8 HTML directly

import { toHtmlBuffer } from "ferromark";
import { createServer } from "node:http";

const server = createServer((_request, response) => {
  response.setHeader("content-type", "text/html; charset=utf-8");
  response.end(toHtmlBuffer("# Hello"));
});
server.listen(3000, "127.0.0.1");

toHtmlBuffer() returns a Node.js Buffer backed by the native output allocation. It avoids converting HTML into a JavaScript string when the next consumer wants bytes. Reusable renderers also expose renderer.toHtmlBuffer().

Deploy under a subpath

import { toHtml } from "ferromark";

const html = toHtml("[Guide](/guide)", { linkBasePath: "/docs" });
console.log(html);

This enables v2 site routing: internal absolute links, image sources, and root-absolute raw HTML URLs use the base. Markdown links convert to index.html routes. Check representative pages when migrating from v1.

Next: syntax highlighting with Ferriki or deployment requirements.