Now liveThe Skillselion MCP - thousands of ranked skills, loaded into your agent mid-task. No install.Get it →
sickn33 avatar

Clerk Auth

  • 849 installs
  • 44.4k repo stars
  • Updated August 4, 2026
  • sickn33/antigravity-awesome-skills

clerk-auth is a backend integration skill that provides battle-tested Clerk authentication patterns for Next.js App Router middleware, organizations, webhooks, and user sync for developers shipping secure sign-in flows.

About

clerk-auth is an antigravity-awesome-skills guide sourced from vibeship-spawner-skills with expert patterns for Clerk authentication in modern web apps. Coverage includes complete Next.js 14/15 App Router setup with ClerkProvider, environment variables, SignIn and SignUp components, UserButton session menus, middleware configuration, organization support, webhooks, and user synchronization. Developers reach for clerk-auth when adding production-grade auth to SaaS dashboards or multi-tenant products without reinventing Clerk edge cases. Patterns emphasize secure defaults for route protection, session handling, and backend user sync rather than demo-only snippets. The skill is marked safe-risk community guidance suitable for iterative integration during active backend build work.

  • Complete Next.js App Router setup with ClerkProvider, SignIn, SignUp, and UserButton components
  • Expert patterns for middleware, organizations, webhooks, and user synchronization
  • Ready-to-use environment variable configuration for test and production keys
  • Pre-built route handlers for sign-in, sign-up, and post-auth redirects
  • Production-grade auth implementation that works with both Next.js 14 and 15

Clerk Auth by the numbers

  • 849 all-time installs (skills.sh)
  • +21 installs in the week ending Aug 5, 2026 (Skillselion tracking)
  • Ranked #431 of 2,245 Frontend Development skills by installs in the Skillselion catalog
  • Security screen: LOW risk (skills.sh audit)
  • Data as of Aug 5, 2026 (Skillselion catalog sync)
npx skills add https://github.com/sickn33/antigravity-awesome-skills --skill clerk-auth

Add your badge

Show developers this skill is listed on Skillselion. Paste this into your README.

Listed on Skillselion
Installs849
repo stars44.4k
Security audit3 / 3 scanners passed
Last updatedAugust 4, 2026
Repositorysickn33/antigravity-awesome-skills

How do you add Clerk auth to Next.js App Router?

Get battle-tested patterns for adding secure authentication, organizations, webhooks, and user sync with Clerk.

Who is it for?

Full-stack developers integrating Clerk into Next.js 14/15 SaaS apps needing middleware, organizations, and webhook-backed user sync.

Skip if: Non-Clerk auth stacks, mobile-native auth without a web backend, or teams needing only conceptual OAuth theory without implementation patterns.

When should I use this skill?

A developer asks to add Clerk authentication, middleware, organizations, webhooks, or user sync to a Next.js App Router application.

What you get

ClerkProvider setup, protected routes, sign-in components, webhook handlers, organization config, and user-sync integration code.

  • auth middleware config
  • sign-in route setup
  • webhook handlers

Files

SKILL.mdMarkdownGitHub ↗

Clerk Authentication

Expert patterns for Clerk auth implementation, middleware, organizations, webhooks, and user sync

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

Code_example

Environment variables (.env.local)

NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY=pk_test_... CLERK_SECRET_KEY=sk_test_... NEXT_PUBLIC_CLERK_SIGN_IN_URL=/sign-in NEXT_PUBLIC_CLERK_SIGN_UP_URL=/sign-up NEXT_PUBLIC_CLERK_AFTER_SIGN_IN_URL=/dashboard NEXT_PUBLIC_CLERK_AFTER_SIGN_UP_URL=/onboarding

// app/layout.tsx import { ClerkProvider } from '@clerk/nextjs';

export default function RootLayout({ children, }: { children: React.ReactNode; }) { return ( <ClerkProvider> <html lang="en"> <body>{children}</body> </html> </ClerkProvider> ); }

// app/sign-in/[[...sign-in]]/page.tsx import { SignIn } from '@clerk/nextjs';

export default function SignInPage() { return ( <div className="flex justify-center items-center min-h-screen"> <SignIn /> </div> ); }

// app/sign-up/[[...sign-up]]/page.tsx import { SignUp } from '@clerk/nextjs';

export default function SignUpPage() { return ( <div className="flex justify-center items-center min-h-screen"> <SignUp /> </div> ); }

// components/Header.tsx import { SignedIn, SignedOut, SignInButton, UserButton } from '@clerk/nextjs';

export function Header() { return ( <header className="flex justify-between p-4"> <h1>My App</h1> <SignedOut> <SignInButton /> </SignedOut> <SignedIn> <UserButton afterSignOutUrl="/" /> </SignedIn> </header> ); }

Anti_patterns

  • Pattern: ClerkProvider inside page component | Why: Provider must wrap entire app in root layout | Fix: Move ClerkProvider to app/layout.tsx
  • Pattern: Using auth() without middleware | Why: auth() requires clerkMiddleware to be configured | Fix: Set up middleware.ts with clerkMiddleware

References

  • https://clerk.com/docs/nextjs/getting-started/quickstart

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

Code_example

// middleware.ts import { clerkMiddleware, createRouteMatcher } from '@clerk/nextjs/server';

// Define protected route patterns const isProtectedRoute = createRouteMatcher([ '/dashboard(.)', '/settings(.)', '/api/private(.*)', ]);

// Define public routes (optional, for clarity) const isPublicRoute = createRouteMatcher([ '/', '/sign-in(.)', '/sign-up(.)', '/api/webhooks(.*)', ]);

export default clerkMiddleware(async (auth, req) => { // Protect matched routes if (isProtectedRoute(req)) { await auth.protect(); } });

export const config = { matcher: [ // Match all routes except static files '/((?!_next|[^?]\\.(?:html?|css|js(?!on)|jpe?g|webp|png|gif|svg|ttf|woff2?|ico|csv|docx?|xlsx?|zip|webmanifest)).)', // Always run for API routes '/(api|trpc)(.*)', ], };

// Advanced: Role-based protection export default clerkMiddleware(async (auth, req) => { if (isProtectedRoute(req)) { await auth.protect(); }

// Admin routes require admin role if (req.nextUrl.pathname.startsWith('/admin')) { await auth.protect({ role: 'org:admin', }); }

// Premium routes require premium permission if (req.nextUrl.pathname.startsWith('/premium')) { await auth.protect({ permission: 'org:premium:access', }); } });

Anti_patterns

  • Pattern: Multiple middleware.ts files | Why: Causes conflicts and redirect loops | Fix: Use single middleware.ts with route matchers
  • Pattern: Manual redirects in components | Why: Double redirects, missed routes | Fix: Handle all redirects in middleware
  • Pattern: Missing matcher config | Why: Middleware won't run on all routes | Fix: Add comprehensive matcher pattern

References

  • https://clerk.com/docs/reference/nextjs/clerk-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

Code_example

// app/dashboard/page.tsx (Server Component) import { auth, currentUser } from '@clerk/nextjs/server'; import { redirect } from 'next/navigation';

export default async function DashboardPage() { const { userId } = await auth();

if (!userId) { redirect('/sign-in'); }

// Full user data (counts toward rate limits) const user = await currentUser();

return ( <div> <h1>Welcome, {user?.firstName}!</h1> <p>Email: {user?.emailAddresses[0]?.emailAddress}</p> </div> ); }

// Using auth() for quick checks export default async function ProtectedLayout({ children, }: { children: React.ReactNode; }) { const { userId, orgId, orgRole } = await auth();

if (!userId) { redirect('/sign-in'); }

// Check organization access if (!orgId) { redirect('/select-org'); }

return ( <div> <p>Organization Role: {orgRole}</p> {children} </div> ); }

// Server Action with auth check // app/actions/posts.ts 'use server'; import { auth } from '@clerk/nextjs/server';

export async function createPost(formData: FormData) { const { userId } = await auth();

if (!userId) { throw new Error('Unauthorized'); }

const title = formData.get('title') as string;

// Create post with userId const post = await prisma.post.create({ data: { title, authorId: userId, }, });

return post; }

Anti_patterns

  • Pattern: Not awaiting auth() | Why: auth() is async in App Router | Fix: Use await auth() or const { userId } = await auth()
  • Pattern: Using currentUser() for simple checks | Why: Counts toward rate limits, slower than auth() | Fix: Use auth() for userId checks, currentUser() for user data

References

  • https://clerk.com/docs/references/nextjs/auth

Client Component Hooks

Access auth state in Client Components using hooks.

Key hooks:

  • useUser(): User object and loading state
  • useAuth(): Auth state, signOut, etc.
  • useSession(): Session object
  • useOrganization(): Current organization

Code_example

// components/UserProfile.tsx 'use client'; import { useUser, useAuth } from '@clerk/nextjs';

export function UserProfile() { const { user, isLoaded, isSignedIn } = useUser(); const { signOut } = useAuth();

if (!isLoaded) { return <div>Loading...</div>; }

if (!isSignedIn) { return <div>Not signed in</div>; }

return ( <div> <img src={user.imageUrl} alt={user.fullName ?? ''} /> <h2>{user.fullName}</h2> <p>{user.emailAddresses[0]?.emailAddress}</p> <button onClick={() => signOut()}>Sign Out</button> </div> ); }

// Organization context 'use client'; import { useOrganization, useOrganizationList } from '@clerk/nextjs';

export function OrgSwitcher() { const { organization, membership } = useOrganization(); const { setActive, userMemberships } = useOrganizationList({ userMemberships: { infinite: true }, });

if (!organization) { return <p>No organization selected</p>; }

return ( <div> <p>Current: {organization.name}</p> <p>Role: {membership?.role}</p>

<select onChange={(e) => setActive?.({ organization: e.target.value })} value={organization.id} > {userMemberships.data?.map((mem) => ( <option key={mem.organization.id} value={mem.organization.id}> {mem.organization.name} </option> ))} </select> </div> ); }

// Protected client component 'use client'; import { useAuth } from '@clerk/nextjs'; import { useRouter } from 'next/navigation'; import { useEffect } from 'react';

export function ProtectedContent() { const { isLoaded, userId } = useAuth(); const router = useRouter();

useEffect(() => { if (isLoaded && !userId) { router.push('/sign-in'); } }, [isLoaded, userId, router]);

if (!isLoaded || !userId) { return <div>Loading...</div>; }

return <div>Protected content here</div>; }

Anti_patterns

  • Pattern: Not checking isLoaded | Why: Auth state undefined during hydration | Fix: Always check isLoaded before accessing user/auth state
  • Pattern: Using hooks in Server Components | Why: Hooks only work in Client Components | Fix: Use auth() and currentUser() in Server Components

References

  • https://clerk.com/docs/references/react/use-user

Organizations and Multi-Tenancy

Implement B2B multi-tenancy with Clerk Organizations.

Features:

  • Multiple orgs per user
  • Roles and permissions
  • Organization-scoped data
  • Enterprise SSO per organization

Code_example

// Organization creation UI // app/create-org/page.tsx import { CreateOrganization } from '@clerk/nextjs';

export default function CreateOrgPage() { return ( <div className="flex justify-center"> <CreateOrganization afterCreateOrganizationUrl="/dashboard" /> </div> ); }

// Organization profile and management // app/org-settings/page.tsx import { OrganizationProfile } from '@clerk/nextjs';

export default function OrgSettingsPage() { return <OrganizationProfile />; }

// Organization switcher in header // components/Header.tsx import { OrganizationSwitcher, UserButton } from '@clerk/nextjs';

export function Header() { return ( <header className="flex justify-between p-4"> <OrganizationSwitcher hidePersonal afterCreateOrganizationUrl="/dashboard" afterSelectOrganizationUrl="/dashboard" /> <UserButton /> </header> ); }

// Org-scoped data access // app/dashboard/page.tsx import { auth } from '@clerk/nextjs/server'; import { prisma } from '@/lib/prisma';

export default async function DashboardPage() { const { orgId } = await auth();

if (!orgId) { redirect('/select-org'); }

// Fetch org-scoped data const projects = await prisma.project.findMany({ where: { organizationId: orgId }, });

return ( <div> <h1>Projects</h1> {projects.map((p) => ( <div key={p.id}>{p.name}</div> ))} </div> ); }

// Role-based UI 'use client'; import { useOrganization, Protect } from '@clerk/nextjs';

export function AdminPanel() { const { membership } = useOrganization();

// Using Protect component return ( <Protect role="org:admin" fallback={<p>Admin access required</p>}> <div>Admin content here</div> </Protect> );

// Or manual check if (membership?.role !== 'org:admin') { return <p>Admin access required</p>; }

return <div>Admin content here</div>; }

Anti_patterns

  • Pattern: Not scoping data by orgId | Why: Data leaks between organizations | Fix: Always filter queries by orgId from auth()
  • Pattern: Hardcoding role strings | Why: Typos cause access issues | Fix: Define role constants or use TypeScript enums

References

  • https://clerk.com/docs/guides/organizations
  • https://clerk.com/articles/multi-tenancy-in-react-applications-guide

Webhook User Sync

Sync Clerk users to your database using webhooks.

Key webhooks:

  • user.created: New user signed up
  • user.updated: User profile changed
  • user.deleted: User deleted account

Uses svix for signature verification.

Code_example

// app/api/webhooks/clerk/route.ts import { Webhook } from 'svix'; import { headers } from 'next/headers'; import { WebhookEvent } from '@clerk/nextjs/server'; import { prisma } from '@/lib/prisma';

export async function POST(req: Request) { const WEBHOOK_SECRET = process.env.CLERK_WEBHOOK_SECRET;

if (!WEBHOOK_SECRET) { throw new Error('Missing CLERK_WEBHOOK_SECRET'); }

// Get headers const headerPayload = await headers(); const svix_id = headerPayload.get('svix-id'); const svix_timestamp = headerPayload.get('svix-timestamp'); const svix_signature = headerPayload.get('svix-signature');

if (!svix_id || !svix_timestamp || !svix_signature) { return new Response('Missing svix headers', { status: 400 }); }

// Get body const payload = await req.json(); const body = JSON.stringify(payload);

// Verify webhook const wh = new Webhook(WEBHOOK_SECRET); let evt: WebhookEvent;

try { evt = wh.verify(body, { 'svix-id': svix_id, 'svix-timestamp': svix_timestamp, 'svix-signature': svix_signature, }) as WebhookEvent; } catch (err) { console.error('Webhook verification failed:', err); return new Response('Verification failed', { status: 400 }); }

// Handle events const eventType = evt.type;

if (eventType === 'user.created') { const { id, email_addresses, first_name, last_name, image_url } = evt.data;

await prisma.user.create({ data: { clerkId: id, email: email_addresses[0]?.email_address, firstName: first_name, lastName: last_name, imageUrl: image_url, }, }); }

if (eventType === 'user.updated') { const { id, email_addresses, first_name, last_name, image_url } = evt.data;

await prisma.user.update({ where: { clerkId: id }, data: { email: email_addresses[0]?.email_address, firstName: first_name, lastName: last_name, imageUrl: image_url, }, }); }

if (eventType === 'user.deleted') { const { id } = evt.data;

await prisma.user.delete({ where: { clerkId: id! }, }); }

return new Response('Webhook processed', { status: 200 }); }

// Prisma schema // prisma/schema.prisma model User { id String @id @default(cuid()) clerkId String @unique email String @unique firstName String? lastName String? imageUrl String? createdAt DateTime @default(now()) updatedAt DateTime @updatedAt

posts Post[] @@index([clerkId]) }

Anti_patterns

  • Pattern: Not verifying webhook signature | Why: Anyone can hit your endpoint with fake data | Fix: Always verify with svix
  • Pattern: Blocking middleware for webhook routes | Why: Webhooks come from Clerk, not authenticated users | Fix: Add /api/webhooks(.*)' to public routes
  • Pattern: Not handling race conditions | Why: user.created might arrive after user.updated | Fix: Use upsert instead of create, handle missing records

References

  • https://clerk.com/docs/webhooks/sync-data
  • https://clerk.com/articles/how-to-sync-clerk-user-data-to-your-database

API Route Protection

Protect API routes using auth() from Clerk.

Route Handlers in App Router use auth() for authentication. Middleware provides initial protection, auth() provides in-handler verification.

Code_example

// app/api/projects/route.ts import { auth } from '@clerk/nextjs/server'; import { prisma } from '@/lib/prisma'; import { NextResponse } from 'next/server';

export async function GET() { const { userId, orgId } = await auth();

if (!userId) { return NextResponse.json({ error: 'Unauthorized' }, { status: 401 }); }

// User's personal projects or org projects const projects = await prisma.project.findMany({ where: orgId ? { organizationId: orgId } : { userId, organizationId: null }, });

return NextResponse.json(projects); }

export async function POST(req: Request) { const { userId, orgId } = await auth();

if (!userId) { return NextResponse.json({ error: 'Unauthorized' }, { status: 401 }); }

const body = await req.json();

const project = await prisma.project.create({ data: { name: body.name, userId, organizationId: orgId ?? null, }, });

return NextResponse.json(project, { status: 201 }); }

// Protected with role check // app/api/admin/users/route.ts export async function GET() { const { userId, orgRole } = await auth();

if (!userId) { return NextResponse.json({ error: 'Unauthorized' }, { status: 401 }); }

if (orgRole !== 'org:admin') { return NextResponse.json({ error: 'Forbidden' }, { status: 403 }); }

// Admin-only logic const users = await prisma.user.findMany(); return NextResponse.json(users); }

// Using getAuth in older patterns (not recommended) // For backwards compatibility only import { getAuth } from '@clerk/nextjs/server';

export async function GET(req: Request) { const { userId } = getAuth(req); // ... }

Anti_patterns

  • Pattern: Trusting middleware alone | Why: Middleware can be bypassed (CVE-2025-29927) | Fix: Always verify auth in route handler too
  • Pattern: Not checking orgId for multi-tenant | Why: Users might access other org's data | Fix: Always filter by orgId from auth()

References

  • https://clerk.com/docs/guides/protecting-pages

Sharp Edges

CVE-2025-29927 Middleware Bypass Vulnerability

Severity: CRITICAL

Multiple Middleware Files Cause Conflicts

Severity: HIGH

4KB Session Token Cookie Limit

Severity: HIGH

auth() Requires clerkMiddleware Configuration

Severity: HIGH

Webhook Race Conditions

Severity: MEDIUM

auth() is Async in App Router

Severity: MEDIUM

Middleware Blocks Webhook Endpoints

Severity: MEDIUM

Accessing Auth State Before isLoaded

Severity: MEDIUM

Manual Redirects Cause Double Redirects

Severity: MEDIUM

Organization Data Not Scoped by orgId

Severity: HIGH

Validation Checks

Clerk Secret Key in Client Code

Severity: ERROR

CLERK_SECRET_KEY must only be used server-side

Message: Clerk secret key exposed to client. Use CLERK_SECRET_KEY without NEXT_PUBLIC prefix.

Protected Route Without Middleware

Severity: ERROR

API routes should have middleware protection

Message: API route without auth check. Add middleware protection or auth() check.

Hardcoded Clerk API Keys

Severity: ERROR

Clerk keys should use environment variables

Message: Hardcoded Clerk keys. Use environment variables.

Missing Await on auth()

Severity: ERROR

auth() is async in App Router and must be awaited

Message: auth() not awaited. Use 'await auth()' in App Router.

Multiple Middleware Files

Severity: WARNING

Only one middleware.ts file should exist

Message: Multiple middleware files detected. Use single middleware.ts.

Webhook Route Not Excluded from Protection

Severity: WARNING

Webhook routes should be public

Message: Webhook route may be blocked by middleware. Add to public routes.

Accessing Auth Without isLoaded Check

Severity: WARNING

Check isLoaded before accessing user state in client components

Message: Accessing user without isLoaded check. Check isLoaded first.

Clerk Hooks in Server Component

Severity: ERROR

Clerk hooks only work in Client Components

Message: Clerk hooks in Server Component. Add 'use client' or use auth().

Multi-Tenant Query Without orgId

Severity: WARNING

Organization data should be scoped by orgId

Message: Query without organization scope. Filter by orgId for multi-tenancy.

Webhook Without Signature Verification

Severity: ERROR

Clerk webhooks must verify svix signature

Message: Webhook without signature verification. Use svix to verify.

Collaboration

Delegation Triggers

  • user needs database -> postgres-wizard (User table with clerkId)
  • user needs payments -> stripe-integration (Customer linked to Clerk user)
  • user needs search -> algolia-search (Secured API keys per user)
  • user needs analytics -> segment-cdp (User identification)
  • user needs email -> resend-email (Transactional emails)

When to Use

  • User mentions or implies: adding authentication
  • User mentions or implies: clerk auth
  • User mentions or implies: user authentication
  • User mentions or implies: sign in
  • User mentions or implies: sign up
  • User mentions or implies: user management
  • User mentions or implies: multi-tenancy
  • User mentions or implies: organizations
  • User mentions or implies: sso
  • User mentions or implies: single sign-on

Limitations

  • Use this skill only when the task clearly matches the scope described above.
  • Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
  • Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.

Related skills

FAQ

Which Next.js versions does clerk-auth cover?

clerk-auth covers Clerk authentication setup for Next.js 14 and 15 App Router. Patterns include ClerkProvider, environment variables, SignIn and SignUp components, and UserButton session management.

Does clerk-auth include organization and webhook patterns?

clerk-auth includes expert patterns for Clerk organizations, webhooks, and user sync alongside middleware and route protection. Developers use it for production multi-tenant SaaS authentication flows.

Is Clerk Auth safe to install?

skills.sh reports 3 of 3 security scanners passed. Review the Security Audits panel on this page before installing in production.

Frontend Developmentintegrationsfrontend

This week in AI coding

Five minutes, every Monday - the tools, releases and tactics for developers.

unsubscribe anytime.