What is Cloudflare Workers URL-Based Module Registry?

Serverless computing lets developers run code on a cloud provider's machines without managing those servers themselves, though servers are still used behind the scenes. Programs in this setting are built from many separate code files, called modules, so the runtime needs a dependable way to find, load and remember each one. The module registry is the part of the Cloudflare Workers runtime that does this for several module formats (the main ones being ESM and CommonJS for JavaScript, and WebAssembly). This project is a rewrite of that registry in workerd, the open-source core of the runtime: it treats every module name as a URL, so relative imports resolve like new URL() and a different query string counts as a separate module. It is enabled with the new_module_registry compatibility flag.

Written from primary sources and reference pages, and checked against them by an independent AI fact-checker. Drafted with AI assistance.