Configuration¶

The site settings live in docs/config.json, under the site key:

{
  "site": {
    "title": "My Project",
    "subtitle": "Official documentation",
    "description": "Documentation for My Project: guides, reference and examples.",
    "footer": "© 2026 My Project",
    "version": "v1.0",
    "lang": "en",
    "url": "https://docs.example.com",
    "repo": "user/repository",
    "branch": "main",
    "contributeUrl": "",
    "logo": "assets/img/logo.svg",
    "image": "assets/img/social-preview.png",
    "rootSection": "General"
  }
}

Key	What it does
`title`	Site name: sidebar header, page titles (`Page · My Project`) and top bar on mobile.
`subtitle`	Bold text above the breadcrumbs. Also part of the home page's `<title>`.
`description`	Meta description of the home page (search engines and social previews). Other pages use their own `description:` or their first paragraph.
`footer`	Page footer.
`version`	Label in the bottom corner of the sidebar. Leave it empty to hide it.
`lang`	Language of the interface and of the `<html lang>` attribute: `en` or `es`. See Languages.
`langLabel`	Text of this language in the language switcher. Defaults to the first two letters of `lang`, uppercase.
`url`	Public address of the site, without trailing slash. Needed for canonical links, the sitemap and social previews. See below.
`repo`	`user/repository`. Enables the "Edit on GitHub" link on every page. Empty = no link.
`branch`	Branch used in that link. Defaults to `main`.
`contributeUrl`	If not empty, shows a second link under "Edit" (for example, your contribution guide).
`logo`	Path to an image for the sidebar, relative to the site root. Without it, the first letter of the title is shown on a colored square.
`image`	Image used for social previews (Open Graph). Defaults to `assets/img/social-preview.png`; 1200×630 works best.
`rootSection`	Name of the section that groups loose `.md` files at the root of `docs/`.

The site URL¶

Canonical links, og:url, the sitemap and hreflang tags need the absolute address of your site. folderdocs finds it in this order:

The SITE_URL environment variable.
site.url in the default language's config.json (docs/config.json).
Automatically on GitHub Actions: https://USER.github.io/REPO (or https://USER.github.io for a USER.github.io repository).

If none applies (for example in a local build), those tags are simply left out. Set site.url if you use a custom domain, because the automatic value points to github.io.

Page front matter¶

Every .md file can start with a front matter block:

Field	Purpose
`title`	Page title in the menu, the heading list and `<title>`.
`description`	Meta description. Defaults to the first paragraph, shortened to 160 characters.
`order`	Position among its siblings.
`id`	Links this page with its translation in another language (same `id` = same page).
`seoTitle`	Overrides the full `<title>` tag, if you want something different from `Title · Site`.

Everything else is generated¶

There is no index.html to edit: titles, descriptions, Open Graph tags, the favicon link and the sitemap are produced for every page at build time. To change the favicon, replace assets/img/favicon.svg; to change the page template, edit tools/lib/template.mjs.