What is interceptor?

Interceptor is a command line tool that lets AI agents control a real browser and, on a Mac, real desktop apps, the same way a human would, instead of spinning up a separate automated browser. It has two parts: a Chrome or Brave extension that runs inside your actual browser, keeping your existing logins, cookies, and open tabs intact, and a Swift daemon on macOS that can drive native apps like Finder, Slack, or Notes using the operating system's own accessibility features. An AI agent controls both surfaces by running interceptor commands from the terminal and reading back their output, so there is no need for a separate protocol like MCP or any API keys. Through the browser extension, an agent can open pages, click and type, read a structured view of the page, watch network requests, and even interact with canvas based editors like Docs, Slides, or Sheets that normal browser automation tools usually cannot reach without simulating real keyboard input at the operating system level. It can also record a person's actual browsing session and turn it into a reusable automated replay. The project positions itself against tools built on the Chrome DevTools Protocol, arguing that using your real, already logged in browser avoids the common problem of a site detecting an automated browser or losing your session state entirely. It can also capture files a page exports directly, like PNGs or PDFs, without needing to click through a save dialog. Installing it means downloading one of two signed macOS installer packages. The lighter Browser package only installs the CLI, daemon, and extension files and needs no special system permissions. The Full package adds the macOS bridge app and asks for Accessibility, Screen Recording, and Apple Events permissions the first time it drives a native app. After installing, the browser extension itself must be loaded manually into Chrome or Brave through developer mode, since browsers do not allow extensions to install themselves outside their official stores. The README warns that Interceptor gives an agent real, meaningful control over your browser and apps, and should be treated accordingly rather than as a harmless script. The full README is longer than what was shown.