Uzumibi

Uzumibi is a Ruby web framework and project generator for WebAssembly-based edge and serverless runtimes. Ruby application code is compiled to mruby bytecode at build time and executed by mruby/edge inside a platform-specific host.

The uzumibi CLI currently provides templates for:

• Cloudflare Workers
• Fastly Compute
• Spin
• Google Cloud Run
• Browser Service Workers
• Browser Web Workers

Documentation

• Beginning Uzumibi
• Uzumibi documentation

Quick start with Cloudflare Workers

Install the CLI and the WebAssembly target:

cargo install uzumibi-cli
rustup target add wasm32-unknown-unknown

Create and run a project:

uzumibi new --template cloudflare my-app
cd my-app
pnpm install
pnpm run dev

Edit lib/app.rb to define routes:

class App < Uzumibi::Router
  get "/" do |req, res|
    res.return(
      200,
      { "content-type" => "text/plain" },
      "Hello from #{RUBY_ENGINE} #{RUBY_VERSION}\n"
    )
  end

  get "/hello/:name" do |req, res|
    res.return(
      200,
      { "content-type" => "text/plain" },
      "Hello, #{req.params[:name]}!\n"
    )
  end
end

$APP = App.new

For Cloudflare Workers, pnpm run dev rebuilds the Wasm module and starts Wrangler. See the Cloudflare Workers guide for request-size configuration, external services, static assets, and Queue consumers.

Workspace components

• uzumibi-cli — generates platform-specific application projects
• uzumibi-gem — defines Uzumibi::Router, Request, and Response
• uzumibi-art-router — route matching and path-parameter extraction
• uzumibi-cloudflare-ext — Cloudflare host APIs exposed to Ruby
• uzumibi-google — Google Cloud integrations used by the Cloud Run template
• uzumibi-on-*-spike directories — development and integration examples for individual runtimes

How to pronounce “Uzumibi”

Uzumibi (うずみび) is pronounced roughly as “oo-zoo-mee-bee.” The Japanese word refers to live embers kept under ash so that the fire does not go out.