This is the official .NET template for scaffolding Umbraco backoffice extensions with TypeScript, Vite, and proper folder structure baked in. You run `dotnet new umbraco-extension -n MyExtension`, optionally add `-ex` for example code including API controllers and dashboard components, then `npm run watch` to start developing. The template handles all the boilerplate so you can jump straight into building sections, dashboards, or custom workspaces. One thing to watch: you must manually add the extension as a project reference to your main Umbraco instance or it won't load, which the skill flags clearly. Solid starting point if you're extending Umbraco's backoffice instead of fighting config.
npx skills add https://github.com/umbraco/umbraco-cms-backoffice-skills --skill umbraco-extension-template