forme-ruby

Render HTML and print CSS to PDF inside Ruby, using the Rust Forme engine. No browser, Node.js, WebAssembly or separate rendering service is needed.

This is an independent MIT-licensed binding maintained by ClearStack, not an official upstream project. 0.1.0 is available on RubyGems.

Add to your Gemfile and run bundle install:

gem "forme-ruby", "~> 0.1.0", require: "forme_pdf"

Or install directly:

gem install forme-ruby -v 0.1.0

RubyGems selects a matching native package where available. The same packages and checksums are available in the GitHub release.

require "forme_pdf"

pdf = FormePDF.render_html("<h1>Hello from Ruby</h1>")
File.binwrite("hello.pdf", pdf)

Ruby 3.2 or later is required. Native packages target Apple Silicon macOS 15+ and Linux AMD64 glibc 2.28+ and need no compiler. Source installs require network access to locked upstream dependencies. See installation.

Version 0.1.0 passed the full release matrix. Red Hat testing uses official UBI images, not RHEL certification. Linux ARM64, Windows and Alpine/musl binaries are not provided. See the installation guide for Ruby and source-build requirements.

Authorize and select application data first, then render explicitly:

html = render_to_string(template: "invoices/pdf", layout: "pdf", formats: [:html])
send_data FormePDF.render_html(html),
  type: "application/pdf", disposition: "inline", filename: "invoice.pdf"

Rails is optional. The Rails guide also covers the opt-in FormePDF::Rails adapter. The gem installs no middleware or routes.

• Rendering guide: CSS, fonts, diagnostics and error handling.
• Development: build, test and contribute.
• Community guidelines: participating respectfully.
• Release guide: package qualification and future publication.
• Changelog, license and third-party notices.

Use trusted HTML and assets. The engine can read local image paths and is not a sandbox for untrusted documents. See security. Report reproducible bugs through GitHub issues with synthetic input, Ruby/platform versions and renderer diagnostics.