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Why I'm Building BrowserOS

Notes on forking Chromium to run AI agents natively in the browser.

May 20, 2026 2 min read

The browser is the single most-used piece of software on a knowledge worker’s machine, and yet it’s the last surface we’ve handed to AI. Tabs, history, bookmarks, forms — every signal an agent could possibly want is locked behind a Chromium process that wasn’t designed to share.

So we forked it.

BrowserOS running an agent in a side panel

What we’re trying to do

BrowserOS is an open-source Chromium fork that exposes the browser’s internals — DOM, network, history, identity — to AI agents through a native API. No extension sandbox, no DOM-scraping hacks, no Playwright running in a separate process pretending to be a user.

A few principles:

  • Local-first. Your browser data stays on your machine. The agent runs against a local model when you want, hosted when you need it.
  • Real automation. When an agent clicks a button, it’s a real click through the Chromium input pipeline — not a synthetic event a site can detect and refuse.
  • Open by default. The whole thing is on GitHub.

Why fork instead of extending

I spent the first month trying to do this as a Chrome extension. Extensions are fine if you want to read the page and pop a sidebar. They are not fine if you want an agent to operate the browser the way a human does.

Some specific walls I hit:

  1. No access to cross-origin frames without permissions a normal user would never grant.
  2. No way to read tab content reliably when sites use shadow DOM or render in canvas.
  3. No persistent process — extensions get suspended, and any agent state with them.

Once you accept that you need first-class hooks into the browser, the question stops being “extension or app” and becomes “fork or build from scratch.” Chromium is 30 million lines of code that already does the hard part.

What’s next

We launched on HN a few weeks ago and crossed 10k stars. The roadmap from here:

  • Agent memory that survives across sessions and tabs
  • Schedulable tasks — “check my Linear inbox every morning at 9”
  • A plugin model so people can ship their own agents without forking the fork

If you want to follow along, the repo is browseros-ai/BrowserOS and I write about the build on Twitter.