Clerk Authentication
Patterns
Next.js App Router Setup
Complete Clerk setup for Next.js 14/15 App Router.
Includes ClerkProvider, environment variables, and basic sign-in/sign-up components.
Key components:
- ClerkProvider: Wraps app for auth context
- <SignIn />, <SignUp />: Pre-built auth forms
- <UserButton />: User menu with session management
Middleware Route Protection
Protect routes using clerkMiddleware and createRouteMatcher.
Best practices:
- Single middleware.ts file at project root
- Use createRouteMatcher for route groups
- auth.protect() for explicit protection
- Centralize all auth logic in middleware
Server Component Authentication
Access auth state in Server Components using auth() and currentUser().
Key functions:
- auth(): Returns userId, sessionId, orgId, claims
- currentUser(): Returns full User object
- Both require clerkMiddleware to be configured
⚠️ Sharp Edges
| Issue | Severity | Solution | |-------|----------|----------| | Issue | critical | See docs | | Issue | high | See docs | | Issue | high | See docs | | Issue | high | See docs | | Issue | medium | See docs | | Issue | medium | See docs | | Issue | medium | See docs | | Issue | medium | See docs |