Microsoft released a quick-start guide for building native WinUI 3 apps on Windows 11 in roughly 30 minutes using free tools. The workflow relies on VS Code, .NET 10, GitHub Copilot's free tier, and Microsoft's winapp CLI, eliminating the need for Visual Studio. Developers scaffold a project, use an AI agent to add features like a settings page, test the result, and package it as an MSIX installer for the Microsoft Store.

The agent, called winui-dev, is a specialized plugin rather than the standard Copilot chatbot. It handles WinUI design, code review, UI testing, packaging, and migration of older apps. Microsoft recommends linking it to its Learn MCP server so it accesses current WinUI documentation instead of relying on training data, which underrepresents WinUI 3 compared to older frameworks like WPF and UWP.

This aligns with Microsoft's push to move developers away from web wrappers and Electron-style apps that consume more RAM than native code. The company dropped the "3" from WinUI's name at Build 2026, signaling its long-term commitment, and has integrated WinUI 3 into parts of Windows 11 like File Explorer's Properties window. Some apps, such as the Windows 11 Weather app, remain Web View2-based and reportedly use significantly more RAM than native alternatives.