sub2mark-site

sub2mark-site generates a static site from a Substack publication using sub2mark-lib.

This tool pulls posts from the Substack RSS feed (falling back to the homepage if needed), converts each post to Markdown, and renders a lightweight static site with a homepage, per-post pages, and an About page. It also downloads the publication favicon and ships it along with some basic styling css and javascript in the generated assets/ folder.

Install

npm install sub2mark-site

Library Usage

import { buildSubstackSite } from 'sub2mark-site';

await buildSubstackSite('https://example.substack.com', {
  outputDir: './site',
  limit: 50,
  update: false
});

Options

• outputDir (string): Output directory for the generated site (default: ./site)
• limit (number): Limit the number of posts processed
• update (boolean): Only add new posts and leave existing posts/assets unchanged

CLI Usage

sub2mark-site https://example.substack.com --out ./site --limit 50

Update mode (incremental):

sub2mark-site https://example.substack.com --out ./site --update

Output

The generated folder is a static site with:

• index.html homepage listing posts
• about/index.html built from the Substack About page
• posts/<slug>/index.html per-post pages with rendered Markdown
• posts/<slug>/post.md the original Markdown
• assets/ shared CSS/JS (dark mode toggle + TOC) plus favicon.*

The site/ folder can be hosted on GitHub Pages, Vercel, Cloudflare Pages, or any static host. It is, as said earlier, static and has no backend.

Note: Works only for free (i.e. non-paywalled) posts currently. For paywalled-posts, only the non-paywalled part is converted to markdown and to html, however small that part maybe.

Update Mode

When update/--update is enabled, the generator runs in incremental mode:

• It only adds brand-new posts that are not already present in posts/.
• It does not regenerate or modify existing post folders.
• It does not rewrite index.html or the about/ page.
• It does not overwrite assets/ (including the favicon).
• If no new posts are found, it logs No new posts found..

Requirements

• Node.js 18+