cross-posted from: hexbear.net/post/7466160

AI-integrated development environment (IDE) company Cursor recently implied it had built a working web browser almost entirely with its AI agents. I won’t say they lied, but CEO Michael Truell certainly tweeted: “We built a browser with GPT-5.2 in Cursor.”

He followed up with: “It’s 3M+ lines of code across thousands of files. The rendering engine is from-scratch in Rust with HTML parsing, CSS cascade, layout, text shaping, paint, and a custom JS VM.”

That sounds impressive, doesn’t it? He also added: “It kind of works,” which is not the most ringing endorsement…

…this week‑long autonomous browser experiment consumed in the order of 10-20 trillion tokens and would have cost several million dollars at then‑current list prices for frontier models.