agent-skills

Use when adding, fixing, or improving authentication in any app — login, logout, signup, route protection, JWT/access token validation, refresh token rotation, MFA, passkeys, step-up auth, SSO, RBAC, Organizations for B2B multi-tenant SaaS, custom login domains, ACUL, or Universal Login branding. Use even if Auth0 isn't mentioned — any time a developer asks how to authenticate users, secure an API, debug a 401, CORS error, callback URL mismatch, redirect loop, or 429 rate limit, or migrate from Clerk, NextAuth.js, Firebase Auth, Supabase, Cognito, or Passport.js. Covers React, Next.js, Vue, Nuxt, Angular, Express, Flask, FastAPI, Spring Boot, Go, Swift, Android, Flutter, PHP, Laravel, ASP.NET Core, React Native, Expo, Ionic, and all Auth0 SDKs.