This is a module for Project Forge. It allows you to build your http server as normal, but load it as a WebAssembly module or Service Worker.
https://github.com/kyleu/projectforge/tree/main/module/wasmserver
Licensed under CC0
To use your app with only WebAssembly, no server process required, run ./bin/build/wasmserver.sh, then host the files in ./tools/wasmserver in an HTTP server (it won't work with file:// urls, and requires SSL for servers other than localhost).
This is of limited utility, since ServiceWorkers aren't allowed to set cookies or other forbidden headers, so the app is quite limited.