Set up Scalajs-Bundler for your project. Contribute missing facades as pull requests. Most of the time this can be done in a few lines of code. You get a good overview of what exists and what is missing when looking at src/main/scala. Each File corresponds to a module in d3: https://devdocs.io/d3~4. To add a new module, simply create a new file and implement the facades you need. Finally add an implicit to your module in D3.scala.