Building a CLI That Controls Any Website Using Chrome DevTools Protocol

Building a CLI That Controls Any Website Using Chrome DevTools Protocol and AI Browser automation has traditionally meant spinning up headless instances, wrestling with authentication flows, and maintaining fragile selectors. But there is a better way. By connecting a CLI tool directly to your existing browser session through the Chrome DevTools Protocol (CDP), you can build command-line interfaces that control any website you are already logged into — no credential management, no CAPTCHA solving, no cookie juggling. In this tutorial, you will build a TypeScript CLI that attaches to a running Chrome instance, executes scripts on live pages, extracts structured data, and bridges the gap between terminal workflows and the modern web. This is the same architectural pattern behind tools like Puppeteer's connect() mode and the emerging Model Context Protocol (MCP) ecosystem that lets AI agents drive browsers. Why Reuse a Live Browser Session? Most web automation tutorials start with puppete