Show HN: One Human + One Agent = One Browser From Scratch in 20K LOC

Summary

One Human + One Agent = One Browser From Scratch 2026-01-27 Just for the fun of it, I thought I'd embark on a week-long quest to generate millions of tokens and millions of lines of source code to create one basic browser that can render HTML and CSS (no JS tho), and hopefully I could use this to receive even more VC investments. But then I remembered that I have something even better: a human brain! It is usually better than any machine at coordinating and thinking through things, so let's see if we can hack something together, one human brain and one LLM agent brain! Demonstration of one-agent-one-browser running with a bunch of different websites on Linux/X11 The above might look like a simple .webm video, but it's actually a highly sophisticated and advanced browser that was super hard to build, encoded as pixels in a video file! Wowzers. Day 1 - Starting out For extra fun when building this, I set these requirements for myself and the agent: I have three days to build it Not a single 3rd party Rust library/dependency allowed Allowed to use anything (commonly) provided out of the box on the OS it runs on Should run on Windows, macOS and common Linux distributions Should be able to render some websites, most importantly, my own blog and Hacker News, should be easy right? The codebase can always compile and be built The codebase should be readable by a human, although code quality isn't the top concern So with these things in mind, I set out on the journal to build a browser "from scratch". I started with something really based, being able to just render "Hello World". Then to be able to render some nested tags. Added the ability of taking screenshots so the agent could use that. Added specifications for HTML/CSS (which I think the agent never used :| ), and tried to nail down the requirements for the agent to use. Also started doing "regression" or "E2E" tests with the screenshotting feature, so we could compare to some baseline images and so on. Added the abilit...