Kiln

Fire a Rails app into a static site.

Docs · Installation · Changelog

Kiln renders every GET route of a Rails app through Rack and writes plain files that any static host can serve. You build pages with normal Rails: routes, controllers, views, helpers, Turbo and Stimulus. Development stays bin/rails server.

Routes are the page list. A route that needs params and has no param source fails the build, and every render error, missing asset and broken link is reported at once. Kiln knows nothing about your data: models and repositories stay ordinary app code.

Requires Ruby 4.0+ and Rails 8.1+.

# Gemfile
gem "kiln"

# config/kiln.rb
Kiln.configure do |config|
  config.url = "https://example.com"
  config.not_found = "/404"
end

Kiln.pages do
  params :post, -> { Post.published.map { { slug: it.slug } } }
  skip :search, reason: "dynamic"
end

RAILS_ENV=production bin/rails kiln:build  # write the site to dist/
bin/rails kiln:serve                       # look at it as a static host serves it

The documentation covers declaring pages, configuration, writing views for a build, the Markdown content layer, testing, deploying and the known limits.

bundle install
bin/test
bin/lint          # RuboCop and bin/house-rules

test/dummy is the Rails app the tests build. docs/ is the documentation site, a Rails app that uses this repository's Kiln. Run bin/rails server there to work on it, and RAILS_ENV=production bin/rails kiln:build and bin/rails test to check it; CI runs both. bin/house-rules rejects em dashes, AI attribution, leftover tool-call markup, filler phrases and dead links in Markdown. AGENTS.md holds the rules a script cannot check.

Releases publish from a vX.Y.Z tag that matches Kiln::VERSION. CI runs first, then the release workflow publishes to RubyGems through trusted publishing.

Copyright © 2026 David Afonso. Kiln is licensed under the MIT License.