npm‑pkg‑lint is a command‑line (and GitHub Action) tool that statically checks an npm package’s tarball and `package.json` against a strict, opinionated set of rules—such as required metadata fields, proper `exports` ordering, disallowed files and dependencies, up‑to‑date Node engine constraints, and lock‑file correctness. It’s aimed at library authors and maintainers who want to enforce best‑practice packaging standards before publishing their modules.