Microsoft has released a new guide that helps developers build a complete WinUI application in about thirty minutes. The guide uses Visual Studio Code, a command-line tool called winapp, and an AI agent that automates much of the development process. The same tool also includes instructions for converting existing WPF and UWP applications into the newer WinUI framework. This effort is part of Microsoft’s broader initiative to gradually replace older parts of the Windows 11 interface with WinUI, a more modern and efficient framework compared to older technologies like Win32 and WebView2. The guide is aimed at third-party developers, with the goal of encouraging them to create more native applications for the Microsoft Store. The AI agent is designed to help developers move away from older frameworks like WPF and UWP by unlearning the traditional habits associated with those systems. The process relies on tools such as Visual Studio Code, .NET 10, the Windows App Development CLI (winapp), WinUI project templates, and GitHub Copilot. A plugin integrated into the system allows the agent to create projects, add features as needed, test the application, convert it into the MSIX format required by the Microsoft Store, and even submit it directly. The AI agent plugin includes eight specific capabilities: creating projects, designing according to Fluent Design standards, reviewing code, testing interfaces, packaging applications, migrating from WPF, generating session reports, and configuring the development environment. Microsoft suggests connecting the agent to its Learn MCP server, which provides real-time access to the latest official documentation, ensuring the AI doesn’t rely solely on its pre-existing training data. For developers looking to migrate existing applications, the guide provides detailed steps. For WPF applications, the transition isn’t as simple as replacing one set of code with another. For example, references to System.Windows.* are changed to Microsoft.UI.Xaml.*, with specific mappings for controls, threads, windows, high-density displays, and data binding. For UWP, the guide notes that the framework is no longer actively developed, and WinUI 3 and the Windows App SDK are now the recommended successors. An AI model trained on years of UWP examples will automatically reproduce common patterns, but the migration skill can guide it to make the correct substitutions when needed.