Cofounder is a full-stack AI-generated application that integrates back-end, database, and stateful web applications. It features a generative UI based on application architecture, complemented by AI-guided sketch design and a modular design system. Although this project is still in its early alpha stage, it has already shown considerable potential, especially in rapid prototyping and development. It aims to provide a complete local, browser-based development environment that supports multiple frameworks and offers a generative design system through integrated AI plugins.