Fibel

Fibel reads Markdown from a content directory and serves it as a website. The source files remain readable in the repository, and every page is additionally available as raw Markdown, so reviewers, scripts, and language models work from the same source the site is built from.

Every built-in capability is a plugin: Markdown rendering, layout, search, theme handling, i18n checks, and SEO output. The default set can be extended, individual plugins can be replaced, and the list can be assembled from scratch. Rendering, navigation, search, and routing therefore remain under project control rather than fixed by the framework.

Fibel runs on Bun and is configured in a single file. Markdown content requires no build step. Applications can additionally place custom server-rendered pages and optional Solid islands inside the same shell while keeping explicit Markdown content for search and tools.

Quick start

bunx --bun @k2b/fibel init
bunx --bun @k2b/fibel dev

init creates fibel.config.ts, a first page under docs/en/, and an assets/ directory. dev serves the project and reloads the browser when a file changes. The development server prints its URL on startup.

Fibel moved from @valentinkolb/fibel to @k2b/fibel in v0.2.0. Existing projects need to replace root imports with @k2b/fibel, plugin imports with @k2b/fibel/plugins, and CLI commands with bunx --bun @k2b/fibel. The previous package is deprecated.

Projects worked on by coding agents should also install the English Fibel Agent Skill directly from this website with the open-source Vercel Skills CLI:

bunx skills add https://fibel.dev

It provides a concise workflow and uses the public Fibel MCP server for exact current details. The agent still answers in the user's language.

Capabilities

• Pages generated from docs/<locale>/**/*.md, with navigation, sections, and pagination derived from frontmatter.
• Custom server-rendered pages with searchable Markdown content and an optional Solid SSR bridge.
• Server-side search with a spotlight dialog, opened with / or Mod+K.
• Native language routes and a language switcher that preserves the current page.
• Light and dark mode resolved on the server, so the first paint is already correct.
• Canonical URLs, hreflang alternates, a sitemap, and structured data for search engines.
• llms.txt and raw .md routes for tools that read documentation directly.
• A plugin API for replacing or extending any built-in behavior.

Machine-readable output

Documentation is increasingly processed by tools rather than read in a browser. Fibel exposes every page in a form those tools can consume, without a separate export step:

/en/configuration        the rendered page
/en/configuration.md     the Markdown source
/llms.txt                an index of all pages, grouped by section
/llms-full.txt           the complete documentation in a single file

These are stable URLs, not file downloads. Pages excluded from navigation are excluded here as well.

Project structure

A Fibel project consists of a config file and a content directory. Assets are optional.

fibel.config.ts
docs/
  en/
    index.md
    configuration.md
  de/
    index.md
    configuration.md
assets/

Each locale has its own directory. docs/en/configuration.md is served as /en/configuration and as /en/configuration.md. Pages sharing a slug across locales are treated as translations of one another, which determines both the language switcher and the hreflang output.

Page model

A page consists of frontmatter and Markdown content.

---
title: Configuration
navTitle: Configuration
section: Start
order: 2
description: Configure routes, locales, assets, theme, and plugins.
tags: [config, routing]
updated: 2026-06-09
---

# Configuration

Frontmatter controls metadata, navigation, and the chips below the page title. All fields are optional: in the absence of title Fibel falls back to the first # heading, and in the absence of description to the first paragraph. The layout renders the title once and omits the first # heading from the body, so it never appears twice.

Next steps

Configuration covers project setup. Hosting describes running Fibel as a server or mounting it inside an existing application. SEO documents what search engines and language models receive. Agent Skills documents website-based skill installation. Built-in plugins lists the default capabilities, and Plugin API describes how to extend them.