The **closure‑compiler** npm package lets Node.js projects include Google’s Closure Compiler as a regular dependency, making the compiler executable available locally for scripts and continuous‑integration pipelines. By installing it with `npm install --save-dev closure-compiler`, developers can run `closure-compiler` from the project’s `node_modules/.bin` directory just like any other CLI tool, simplifying build automation for JavaScript codebases that use Closure Compiler.