@syedmsawaid/astro-substack

Astro integration that pulls every post from your Substack publication into Markdown files in your repo (with images), and gives you a ready-made content collection. If Substack disappears, your newsletter is still in git.

Setup

npm i @syedmsawaid/astro-substack

// astro.config.mjs
import substack from "@syedmsawaid/astro-substack";

export default defineConfig({
  integrations: [substack({ publication: "mypub" })],
});

// src/content.config.ts
import { substackCollection } from "@syedmsawaid/astro-substack/collection";

export const collections = { issues: substackCollection() };

Then getCollection("issues") as usual. Commit src/content/issues/ to git: that is your backup.

What it does

• On every astro dev / astro build it fetches the archive and writes <dir>/<slug>.md with frontmatter (title, subtitle, pubDate, updatedAt, url, coverImage, tags, audience).
• Images are downloaded to <dir>/_images/<slug>/ and linked relatively, so Astro optimizes them.
• Unchanged posts (same updatedAt) are skipped.
• Never deletes files. A post removed or edited away on Substack stays in your backup.
• If Substack is unreachable, the build continues with your local copy.

Options

Option	Default
publication	required	"mypub", "mypub.substack.com" or a custom domain
dir	src/content/issues	Output folder. Pass the same path to substackCollection(dir)
downloadImages	true
sync	true	Set false to use only local files
force	false	Re-download everything
limit	all	Newest N posts
types	["newsletter"]	Also "podcast", "thread"

Only free posts (audience everyone) are backed up. Paid and subscriber-only posts are skipped.

Requires sharp in your project for image optimization (Astro default).