The **module-id** package parses a CommonJS module identifier (e.g., `[email protected]/lib/file.js`) into its constituent parts—package name, optional scope, version, and the internal file path—while also providing a mutable object that can re‑assemble the identifier after changes. It’s aimed at Node.js developers and tooling authors who need to inspect or rewrite module IDs, especially when dealing with scoped packages and versioned dependencies.