CommunityToolkit.Mvvm + The MVVM Toolkit deliberately ships no DI container — it composes with , the same container ASP.NET Core, Worker services, and the .NET Generic Host use. TL;DR. Build the service provider once at startup (prefer ). Register services and ViewModels. Inject through constructors. Avoid in user code. --- When to use this skill - Standing up the composition root for a new XAML app (WPF, WinUI 3, MAUI, Uno, Avalonia) - Choosing service/VM lifetimes - Wiring once and injecting it into ViewModels - Resolving a page's ViewModel without coupling to a service locator - Diagnosing…