This is a comprehensive reference for implementing Auth.js 5 (NextAuth.js) authentication in Next.js 15+ App Router apps. It covers the full setup from installing dependencies and configuring OAuth providers to protecting routes with middleware, securing Server Actions, and implementing role-based access control. You'd reach for this when wiring up GitHub or Google sign-in, protecting dashboard routes, or ensuring your Server Components and Actions actually check authentication before exposing data. The patterns are solid and production-focused, with proper TypeScript types and clear examples of common scenarios like protected dashboards and admin panels. It assumes you're comfortable with App Router conventions but need the Auth.js specifics spelled out.
npx skills add https://github.com/giuseppe-trisciuoglio/developer-kit --skill nextjs-authentication