ruby.wasm
ruby.wasm is a collection of WebAssembly ports of the CRuby. It enables running Ruby application on browsers, WASI compatible WebAssembly runtimes, and Edge Computing platforms.
Try ruby.wasm (no installation needed)
Try ruby.wasm in TryRuby in your browser.
Quick Example: Ruby on browser
Create and save index.html page with the following contents:
<html>
<script src="https://cdn.jsdelivr.net/npm/@ruby/[email protected]/dist/browser.script.iife.js"></script>
<script type="text/ruby">
puts "Hello, world!"
</script>
</html>
Quick Example: How to package your Ruby application as a WASI application
Dependencies: wasi-vfs, wasmtime
# Download a prebuilt Ruby release
$ curl -LO https://github.com/ruby/ruby.wasm/releases/latest/download/ruby-3.2-wasm32-unknown-wasi-full.tar.gz
$ tar xfz ruby-3.2-wasm32-unknown-wasi-full.tar.gz
# Extract ruby binary not to pack itself
$ mv 3.2-wasm32-unknown-wasi-full/usr/local/bin/ruby ruby.wasm
# Put your app code
$ mkdir src
$ echo "puts 'Hello'" > src/my_app.rb
# Pack the whole directory under /usr and your app dir
$ wasi-vfs pack ruby.wasm --mapdir /src::./src --mapdir /usr::./3.2-wasm32-unknown-wasi-full/usr -o my-ruby-app.wasm
# Run the packed scripts
$ wasmtime my-ruby-app.wasm -- /src/my_app.rb
Hello
npm packages (for JavaScript host environments)
See the README.md of each package for more detail and its usage.
| Package | Description | npm |
|---|---|---|
| @ruby/3.2-wasm-wasi | CRuby 3.2 built on WASI with JS interop support |  |
| @ruby/head-wasm-wasi | HEAD CRuby built on WASI with JS interop support |  |
| @ruby/head-wasm-emscripten | HEAD CRuby built on Emscripten (not well tested) |  |
Prebuilt binaries
This project distributes prebuilt Ruby binaries in GitHub Releases. A build is a combination of ruby version, profile, and target.
Supported Target Triples
| Triple | Description |
|---|---|
wasm32-unknown-wasi |
Targeting WASI-compatible environments (e.g. Node.js, browsers with polyfill, wasmtime, and so on) |
wasm32-unknown-emscripten |
Targeting JavaScript environments including Node.js and browsers |
Profiles
| Profile | Description |
|---|---|
minimal |
No standard extension libraries (like json, yaml, or stringio) |
full |
All standard extension libraries |
*-js |
Enabled JS interoperability, only usable with npm package |
*-debug |
With DWARF info and name section for debugging |
Notable Limitations
The current WASI target build does not yet support Thread related APIs. Specifically, WASI does not yet have an API for creating and managing threads yet.
Also there is no support for networking. It is one of the goal of WASI to support networking in the future, but it is not yet implemented.
Contributing
See CONTRIBUTING.md for how to build and test, and how to contribute to this project. Bug reports and pull requests are welcome on GitHub at https://github.com/ruby/ruby.wasm