This teaches Claude how to work with Umbraco's controller pattern for backoffice customization. Controllers are separate classes that handle logic and lifecycle management for UI elements, things like timers, subscriptions, API calls, and cleanup. The skill includes a workflow that fetches live docs first, then generates TypeScript code extending UmbControllerBase with proper lifecycle methods. Examples cover timer controllers, manual registration, and context access. The practical bit is it shows how to manage side effects cleanly when elements connect and disconnect from the DOM. One thing to note: it explicitly warns against using raw fetch for API calls, pushing you toward generated OpenAPI clients with Umbraco's auth context instead.
npx skills add https://github.com/umbraco/umbraco-cms-backoffice-skills --skill umbraco-controllers