This is your goto when you're working with Next.js App Router beyond basic pages. It covers Route Handlers for API endpoints, Server Actions with proper file naming conventions (action.ts vs actions.ts), Parallel and Intercepting Routes for modals and drawers, and streaming with Suspense. The big thing here is it's strict about TypeScript (no any types allowed) and gets the Server Actions return types right, which matters because form actions must return void while useActionState lets you return data. Also handles cookies, error boundaries, and draft mode. Useful when you're building forms, mutations, or complex routing patterns and need the patterns spelled out correctly.
npx skills add https://github.com/wsimmonds/claude-nextjs-skills --skill nextjs-advanced-routing