Cursor AI CEO shares GPT 5.2 agents building a 3M+ lines web browser in a week

**Cursor AI CEO** Michael Truell shared a clip showing GPT 5.2 powered multi agent systems building a full web browser in about a week. The run **produced** over 3 million lines of code including a custom rendering engine and JavaScript VM. The **project** is experimental and not production ready but demonstrates how far autonomous coding agents can scale when run continuously. The **visualization** shows agents coordinating and evolving the codebase in real time. **Source: Michael X** Tweet