RSS as a cross-site content bridge in Astro SSG

Two static sites. One is a portfolio (christianecg.com), built with Astro and deployed to GitHub Pages. The other is this notebook (octa.page), where active writing happens. The portfolio had a /blog section — but all the articles in it were from 2021–2022. The writing had moved to octa.page and the two were completely siloed.

The technical debt: a blog section showing stale content while the active equivalent existed elsewhere and neither site knew about the other.

Why RSS and not something else

The options were roughly:

1. Shared CMS or database — overkill for two static sites. Introduces infrastructure neither site needs.
2. Git submodule or monorepo — couples the two repos, complicates deploys.
3. Direct fetch from the octa.page source files — would require shared repo access and tight coupling.
4. RSS — octa.page already exposes /rss.xml. It's a stable contract. Stateless, versionless, requires nothing from the consumer.

RSS wins by elimination. It's also the right abstraction: octa.page doesn't need to know christianecg.com exists. The feed is an implementation detail of octa's public interface, consumed unilaterally.

Build-time consumption in Astro

Astro SSG runs fetch at build time in the page's frontmatter. No runtime, no hydration — the HTML is generated once with whatever the feed returns at that moment.

let octaArticles: Article[] = [];
try {
  const res = await fetch('https://octa.page/rss.xml');
  const xml = await res.text();
  octaArticles = [...xml.matchAll(/([\s\S]*?)<\/item>/g)].flatMap(([, item], i) => {
    const title = item.match(/