subcommand is a tiny Node.js library for building command‑line tools that have sub‑commands (e.g., `git commit`, `npm install`). It lets you declare a JSON configuration of commands, options, and handlers, then routes parsed arguments to the appropriate function, with built‑in support for defaults, root handling, usage/help printing, and “all/none” callbacks. It’s aimed at developers who need a lightweight, configurable CLI router without pulling in a full‑featured framework.