Fast, modern documentation engine powered by Bun, inspired by VitePress

BunPress is a lightning-fast static site generator designed specifically for documentation. Built on top of Bun's blazing performance with a developer-friendly API inspired by VitePress.

Features

Core Features

• ⚡ Lightning Fast - 0.18s build time (4,000 files), 11x faster than Eleventy
• 📝 Rich Markdown - VitePress-compatible markdown with containers, alerts, code groups, and syntax highlighting
• 📋 Smart TOC - Automatic table of contents with filtering, positioning (sidebar/inline/floating), and interactive navigation
• 🛠️ Developer Friendly - Native TypeScript support, comprehensive CLI (15+ commands), and extensive customization

SEO & Analytics

• 🔍 Complete SEO - Auto-generated sitemap.xml, robots.txt, Open Graph tags, and JSON-LD structured data
• 📊 Fathom Analytics - Privacy-focused analytics with GDPR/CCPA compliance and DNT support
• 🔎 SEO Validation - Built-in SEO checker with auto-fix mode for common issues

Markdown Extensions (VitePress-Compatible)

• ✅ Custom containers (info, tip, warning, danger, details, raw)
• ✅ GitHub-flavored alerts (note, tip, important, warning, caution)
• ✅ Code features (line highlighting, line numbers, focus, diffs, errors/warnings, groups)
• ✅ Code imports from files with line ranges and regions
• ✅ Tables with alignment and formatting
• ✅ Image enhancements with captions and lazy loading
• ✅ Custom header anchors and inline TOC
• ✅ STX template syntax in markdown — dynamic content with @if, @foreach, {{ }}, <script server>

Developer Experience

• 🚀 Fast Dev Server - ~100ms startup, hot reload, and instant feedback
• 📦 Small Bundles - ~45KB per page (HTML + JS + CSS)
• 💚 Low Memory - ~50MB dev server, ~250MB peak for 1000 files
• 🎯 15+ CLI Commands - Build, dev, preview, stats, doctor, SEO check, and more

Quick Start

Get started with BunPress in seconds:

# Install BunPress
bun add @stacksjs/bunpress

# Create a new documentation site
mkdir my-docs
cd my-docs

# Initialize with basic structure
bunx @stacksjs/bunpress init

# Start development server
bun run dev

# Build for production
bun run build

Basic Usage

Create your first documentation page:

---
title: Welcome
layout: home
---

# Welcome to My Project

This is my awesome project documentation built with BunPress!

## Quick Links

- [Getting Started](/guide/getting-started)
- [API Reference](/api)
- [Examples](/examples)

Configure your site in bunpress.config.ts:

export default {
  title: 'My Documentation',
  description: 'Built with BunPress',
  nav: [
    { text: 'Home', link: '/' },
    { text: 'Guide', link: '/guide' },
    { text: 'API', link: '/api' }
  ],

  // SEO Configuration
  sitemap: {
    enabled: true,
    baseUrl: 'https://mysite.com',
  },
  robots: {
    enabled: true,
  },

  // Analytics
  fathom: {
    enabled: true,
    siteId: 'YOUR_SITE_ID',
    honorDNT: true,
  },
}

STX Templates in Markdown

BunPress supports STX template syntax directly inside markdown files. This enables dynamic content generation — conditionals, loops, computed values, and more — powered by the STX templating engine.

Server Scripts

Define variables and logic in <script server> blocks:

<script server>
const features = [
  { name: 'Fast', desc: 'Built with Zig for maximum performance' },
  { name: 'Modern', desc: 'ES modules and TypeScript native' },
  { name: 'Simple', desc: 'Zero config, one binary' },
]
const showBeta = false
</script>

# Features

@foreach (features as feature)
### {{ feature.name }}

{{ feature.desc }}

@endforeach

@if (showBeta)
## Beta Features

These features are coming soon.
@endif

Available Directives

Frontmatter Access

Frontmatter values are automatically available in STX expressions:

---
title: My Page
author: Chris
---

# {{ title }}

Written by {{ author }}.

Inline Expressions

Use expressions anywhere in your markdown:

<script server>
const count = 42
const items = ['Alpha', 'Beta', 'Gamma']
</script>

There are {{ count }} items and {{ items.length }} categories.
The sum is {{ 10 + 20 + 12 }}.

STX processing happens before markdown conversion, so the output of STX directives is treated as regular markdown and rendered accordingly — headings, lists, bold, code blocks, and all other markdown features work as expected.

CLI Commands

BunPress provides a comprehensive CLI for managing your documentation:

# Development
bunpress dev              # Start dev server with hot reload
bunpress build            # Build for production
bunpress preview          # Preview production build

# Content Management
bunpress new <path>       # Create new markdown file
bunpress init             # Initialize new project

# Maintenance
bunpress clean            # Remove build artifacts
bunpress stats            # Show documentation statistics
bunpress doctor           # Run diagnostic checks

# SEO
bunpress seo:check        # Check SEO for all pages
bunpress seo:check --fix  # Auto-fix SEO issues

# Configuration
bunpress config:show      # Show current configuration
bunpress config:validate  # Validate configuration

Performance Benchmarks

BunPress is the fastest documentation generator available, powered by Bun's built-in Zig-based markdown parser.

Markdown Engine Benchmarks

Real benchmark results comparing BunPress against documentation frameworks and popular markdown engines. All engines configured with equivalent GFM features (tables, strikethrough, task lists, autolinks). Tested on Apple M3 Pro, 18GB RAM, Bun 1.3.10.

Fairness note: These results are conservative. Real VitePress adds Shiki syntax highlighting + Vue plugins on top of markdown-it. Real Astro adds Shiki on top of remark/rehype. commonmark.js does not support GFM, so it processes fewer features and appears artificially fast.

Simple Markdown (paragraph + inline formatting)

Real-World Doc Page (~3KB markdown)

Large Document Stress Test (~33KB markdown)

Throughput: 100 Mixed Documents

Build Performance (4,000 markdown files)

Using the same methodology as 11ty's official performance tests:

Full-Featured Build (with syntax highlighting)

Run the benchmarks yourself:

cd benchmark && bun install && bun run bench

Testing

bun test              # Run all tests
bun test:quick        # Quick test run (10s timeout)
bun run typecheck     # Type checking
bun run lint          # Lint code

Changelog

Please see our releases page for more information on what has changed recently.

Contributing

Please see CONTRIBUTING for details.

Community

For help, discussion about best practices, or any other conversation that would benefit from being searchable:

Discussions on GitHub

For casual chit-chat with others using this package:

Join the Stacks Discord Server

Postcardware

“Software that is free, but hopes for a postcard.” We love receiving postcards from around the world showing where Stacks is being used! We showcase them on our website too.

Our address: Stacks.js, 12665 Village Ln #2306, Playa Vista, CA 90094, United States 🌎

Sponsors

We would like to extend our thanks to the following sponsors for funding Stacks development. If you are interested in becoming a sponsor, please reach out to us.

• JetBrains
• The Solana Foundation

License

The MIT License (MIT). Please see LICENSE for more information.

Made with 💙