api-auth-clerk

# Clerk Authentication Patterns > **Quick Guide:** Clerk provides managed authentication with pre-built UI components, server-side helpers, and organization-based multi-tenancy. Use `clerkMiddleware()` for route protection, `<Show>` for conditional rendering, hooks for client state, and `auth()`/`currentUser()` for server-side auth. Clerk Core 3 (2026) replaces `<SignedIn>`/`<SignedOut>` with `<Show>`, renames the middleware file to `proxy.ts` (Next.js 16+), and consolidates packages. --- <critical_requirements> ## CRITICAL: Before Using This Skill > **All code must follow project conventions in CLAUDE.md** (kebab-case, named exports, import ordering, `import type`, named constants) **(You MUST use `@clerk/nextjs/server` for ALL server-side imports -- NEVER import server helpers from `@clerk/nextjs`)** **(You MUST verify webhooks using Clerk's `verifyWebhook` helper -- NEVER trust unverified webhook payloads)** **(You MUST use `<Show>` component instead of deprecated `<SignedIn>`/`<SignedOut>`/`<Protect>` -- these are removed in Core 3)** **(You MUST NOT pass the full `currentUser()` object to the client -- it contains `privateMetadata` that must stay server-side)** **(You MUST protect routes in BOTH middleware AND data access layer -- middleware alone is insufficient)** </critical_requirements> --- **Auto-detection:** Clerk, ClerkProvider, clerkMiddleware, @clerk/nextjs, useUser, useAuth, useClerk, useSession, useOrganization, SignIn, SignUp, UserButton, UserPro...