How to Add a Plugin System to Your Node.js CLI Tool

How to Add a Plugin System to Your Node.js CLI Tool The best CLI tools don't try to do everything — they let users extend them. ESLint has plugins for every framework. Prettier has parsers for every language. Babel has transforms for every syntax. Behind each of these is a plugin system that turns a good tool into a platform. Building a plugin system sounds complex, but the core pattern is simple: discover plugins, load them, and call their hooks at the right time. This article shows you how to build one from scratch. What Makes a Good Plugin System Before writing code, let's define what we need: Discovery — find plugins in node_modules or local paths Loading — import and validate plugin modules Hooks — defined points where plugins can inject behavior Configuration — per-plugin settings Ordering — plugins run in a predictable sequence The Plugin Interface Start with a TypeScript interface that defines what a plugin looks like: // src/types.ts export interface Plugin { name : string ; v