app.build is an open-source AI agent designed to create and deploy full-stack applications, offering features such as end-to-end tests and automated deployments. Despite discontinuing its managed version, the source code remains available for those interested in building similar agents. The tool allows users to generate applications from scratch or iterate on existing ones, and it supports local execution, enabling developers to use their preferred models. By employing a divide-and-conquer approach, app.build ensures high-quality applications by breaking down app creation into independent tasks that undergo rigorous checks. The project aims to foster a community of developers to contribute and innovate, with plans for a public roadmap and further resources to support users in understanding the agent's architecture and capabilities.