SEO and discovery

The SEO plugin describes each page for search engines. The llms plugin publishes the same content in a form language models can consume. Both work without configuration, but a published site should set siteUrl.

Set the site URL

export default defineFibel({
  title: "My Docs",
  siteUrl: "https://docs.example.com",
});

siteUrl turns canonical URLs, language alternates, structured data, and sitemap entries into absolute URLs. Without it Fibel emits relative paths and crawlers reject the sitemap. Fibel prints a warning at startup when the value is missing.

Language alternates

Multilingual documentation competes with itself when search engines treat translations as separate pages. Fibel links them instead.

<link rel="alternate" hreflang="en" href="https://docs.example.com/en/configuration">
<link rel="alternate" hreflang="de" href="https://docs.example.com/de/configuration">
<link rel="alternate" hreflang="x-default" href="https://docs.example.com/en/configuration">

Pages are matched by slug. docs/en/configuration.md and docs/de/configuration.md form one group. The x-default entry points at the default locale. The same alternates are repeated in the sitemap.

Sitemap and robots

/sitemap.xml
/robots.txt

The sitemap lists every visible page with an absolute URL, its updated date as lastmod, and the language alternates. robots.txt disallows the internal path and any path listed in seo.disallow, then points at the sitemap.

Pages with hidden: true are left out of the sitemap and rendered with a noindex meta tag.

Social cards

export default defineFibel({
  title: "My Docs",
  seo: {
    ogImage: "/assets/social.png",
    twitterSite: "@example",
  },
});

Fibel renders Open Graph and Twitter card tags from the page title and description. ogImage is the default preview image; a page overrides it with image in its frontmatter. Cards switch to the large format when an image is available.

Structured data

Every indexable page carries JSON-LD with a TechArticle. Content pages add a BreadcrumbList built from the sidebar section. Locale index pages add a WebSite entry instead of the breadcrumbs.

Fibel does not declare a SearchAction. That markup promises crawlers a URL that renders search results as a page, and Fibel's search is a JSON endpoint used by the spotlight dialog.

Routes for language models

/llms.txt              index for the default locale
/en/llms.txt           index for a specific locale
/llms-full.txt         every page of the default locale in one file
/en/llms-full.txt      every page of a locale in one file

The index follows the llms.txt convention: a title, a short summary, then the pages grouped by sidebar section. Each entry links to the raw Markdown route with its description, so a model can fetch exactly the page it needs. llms-full.txt inlines the Markdown of every page for tools that prefer one request.

Hidden pages are excluded from both.

Custom head tags

Analytics snippets and verification tags belong in a plugin rather than in a replaced layout. The Plugin API documents the headTags hook.