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
• , : Pre-built auth forms
• : 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 |