rustkyll

A fast, drop-in replacement for Jekyll, written in Rust.

rustkyll reads the same source files as Jekyll - Markdown with YAML front matter, Liquid templates, YAML data files, collections - and usually produces equivalent HTML output much faster.

uvx rustkyll serve

Run this in any Jekyll site directory. That's it.

Tested on 50+ Jekyll sites. Fresh benchmark run on 2026-04-02. Here are some highlights:

Median wall-clock time over 3 runs, clean builds, no caching. Full results in docs/benchmark/results.md.

uvx rustkyll build --source /path/to/site

# Or install globally
uv tool install rustkyll

pip install rustkyll

curl -fsSL https://raw.githubusercontent.com/alexeygrigorev/rustkyll/main/scripts/install.sh | sh

Installs the latest release into ~/.local/bin. Override with environment variables:

RUSTKYLL_VERSION=v0.4.5 RUSTKYLL_INSTALL_DIR=~/bin \
  curl -fsSL https://raw.githubusercontent.com/alexeygrigorev/rustkyll/main/scripts/install.sh | sh

Download from GitHub Releases:

git clone https://github.com/alexeygrigorev/rustkyll.git
cd rustkyll
cargo build --release

rustkyll build --source /path/to/site --destination /path/to/output

Flags:

• --source - path to Jekyll site directory (default: .)
• --destination - output directory (default: _site)
• --incremental - only rebuild changed pages
• --force - force full rebuild, ignoring incremental manifest

rustkyll serve --source /path/to/site --port 4000

Starts a local dev server with live reload. Flags:

• --port - HTTP server port (default: 4000)
• --livereload / --no-livereload - toggle browser auto-refresh (default: on)
• --no-browser - don't auto-open browser

138 of 166 Jekyll features are fully implemented, with 7 more partially implemented. See docs/jekyll-compatibility.md for the full matrix.

Core:

• Config parsing, front matter, Markdown (GFM)
• Layouts with inheritance, includes with parameters
• Permalinks (named styles and custom patterns)
• Sass/SCSS compilation, static file copying
• YAML and JSON data files
• Excerpts

Collections:

• Posts, custom collections, pagination
• Categories, tags, page.previous/page.next
• site.categories, site.tags, site.related_posts, site.pages

Liquid:

• All standard tags: for, if, unless, case, capture, assign, raw, comment, highlight, tablerow, cycle, increment/decrement
• Jekyll-specific tags: link, post_url, seo, avatar, feed_meta
• 70+ filters including where, where_exp, group_by, group_by_exp, markdownify, slugify, jsonify, relative_url, absolute_url, sample, cgi_escape, uri_escape, and all Liquid stdlib filters

Jekyll plugin equivalents:

• jekyll-seo-tag, jekyll-feed, jekyll-sitemap, jekyll-paginate, jekyll-avatar, jekyll-archives, jekyll-redirect-from

Extensions:

• Opt-in extensions: block for post-render HTML transforms. Entries can be extensions that are part of rustkyll or external WASM extensions.

• wikilinks, which is part of rustkyll, for wiki-style cross-links such as [[target]] and [[target|label]], resolved against pages and collections:

  extensions:
    - wikilinks:
        scope: [wiki]
        on_broken: warn

• External WASM extensions loaded from the site, for example:

  extensions:
    - wasm:
        path: _extensions/chips.wasm
        config:
          scope: "wiki"

  WASM extensions are supported by default builds and are useful for site-specific transforms such as podwiki's build-time entity chips. They run through the same extension pipeline as rustkyll's own transforms.

rustkyll already implements many common Jekyll plugins directly, including SEO tags, feeds, sitemaps, pagination, avatars, archives, redirects, jemoji, mentions, and wikilinks. If a Ruby plugin's functionality is missing and it can be expressed as a post-render HTML transform, create an _extensions/ folder in your site, build a WASM extension there, and point _config.yml at the .wasm file:

extensions:
  - wasm: _extensions/my_extension.wasm

Prompt for porting a Ruby plugin with a coding agent:

Convert this Jekyll Ruby plugin into a rustkyll WASM extension.

Context:
- rustkyll does not load Ruby plugins.
- The extension should be an Extism WASM plugin, preferably written in Rust.
- It is a post-render HTML transform: input JSON is
  { "html": "...", "collection": "wiki-or-null", "baseurl": "" }.
- It must export `transform` and return JSON:
  { "html": "...", "warnings": [] }.
- Optional config is passed as JSON in the Extism config key `config`.
- The host provides `resolve_link(target) -> url`, returning an empty string on miss.
- Filesystem and network access are denied by default.

Task:
1. Read the Ruby plugin and summarize which behavior can be implemented with this HTML-transform ABI.
2. Reimplement that behavior from scratch as a WASM extension.
3. Add a minimal fixture site using `_extensions/<name>.wasm` in `_config.yml`.
4. Add tests proving the generated HTML matches the Ruby plugin's intended behavior.
5. Document build instructions and any Ruby plugin features that cannot be represented by the current ABI.

Extras:

• Parallel page generation with rayon
• Live reload via WebSocket
• Progress bar and build timing breakdown
• Lenient template rendering (unknown filters warn instead of failing)

• No gem-based themes. Themes must be present as local layout/include files.
• No Ruby plugin system. Ruby plugins are not loaded; use the Jekyll plugin equivalents above or opt-in extensions/WASM transforms for post-render HTML changes.
• No CSV/TSV data files. Only YAML and JSON are loaded.
• Incremental builds don't track layout/include changes. Use --force after modifying layouts.
• Syntax highlighting classes may differ slightly from Rouge (Jekyll uses Rouge, rustkyll uses syntect).

rustkyll was developed entirely by AI agents - a Product Manager, Software Engineer, and Tester - collaborating through a structured pipeline. See docs/PROCESS.md for details.

This project is not yet published under a specific license. See the repository for updates.