Imported from shipshitdev/skills (skills/clerk-validator/SKILL.md). Install upstream with npx skills add shipshitdev/skills --skill clerk-validator. Copyright stays with the author.

Clerk Validator

Validates Clerk authentication configuration and enforces modern Clerk patterns with Next.js 16.

When This Activates

• Setting up Clerk authentication
• Before any auth implementation work
• Auditing existing Clerk configuration
• After AI generates Clerk code
• CI/CD pipeline validation

Quick Start

python3 scripts/validate.py --root .
python3 scripts/validate.py --root . --strict

What Gets Checked

1. Package Version

// GOOD: Latest Clerk
"@clerk/nextjs": "^6.0.0"

// BAD: Old version
"@clerk/nextjs": "^4.0.0"

2. Proxy vs Middleware (Next.js 16)

GOOD - Next.js 16:

// proxy.ts
import { clerkMiddleware } from "@clerk/nextjs/server";
export default clerkMiddleware();

BAD - Deprecated:

// middleware.ts (deprecated in Next.js 16)
import { authMiddleware } from "@clerk/nextjs";  // DEPRECATED
export default authMiddleware();

3. ClerkProvider Setup

GOOD: wrap the entire app in <ClerkProvider> inside app/layout.tsx. BAD: placing it in _app.tsx (Pages Router, deprecated) or forgetting to wrap the whole tree.

See references/full-guide.md (§ Root Layout with Clerk Components) for the full layout example.

4. Auth Import Patterns

GOOD - Server-side:

import { auth } from "@clerk/nextjs/server";

export default async function Page() {
  const { userId } = await auth();
  // ...
}

BAD - Old patterns:

// Don't use
import { getAuth } from "@clerk/nextjs/server";  // OLD
import { currentUser } from "@clerk/nextjs";     // Check version

5. Environment Variables

Required:

NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY=pk_...
CLERK_SECRET_KEY=sk_...

Optional but recommended:

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

Deprecated Patterns

Validation Output

=== Clerk Validation Report ===
Package Version: @clerk/nextjs@6.0.0 ✓
Configuration: ✓ ClerkProvider  ✓ proxy.ts  ✗ middleware.ts found (deprecated)
Auth Patterns:  ✓ auth()  ✗ authMiddleware() in 1 file (deprecated)
Summary: 2 issues found

Modern Clerk Patterns

Protected Routes (Server Component)

Call await auth(), redirect to /sign-in when userId is missing, and render only after that check.

See references/full-guide.md (§ Protected Route Example) for the full page.

Protected Routes (Client Component)

Mark the component "use client", read { isLoaded, userId } from useAuth(), and render a loading/redirect state until both are resolved.

See references/full-guide.md (§ Use Auth Hook) for the full component.

API Routes

Call await auth() inside the route handler and return 401 before doing any work when userId is missing.

See references/full-guide.md (§ Protected API Route) for the full handler.

NestJS Guard

Extract the bearer token, verify it with clerkClient.verifyToken, and attach userId to the request; return false/throw on any failure.

See references/full-guide.md (§ Authentication Guard) for the full guard.

Webhook Configuration

Verify the svix-id / svix-timestamp / svix-signature headers with the svix package against CLERK_WEBHOOK_SECRET before trusting the payload; never process an unverified webhook body.

See references/full-guide.md (§ Webhooks (Next.js App Router)) for the full route handler, and (§ Webhook Handler) for the NestJS controller equivalent.

CI/CD Integration

# .github/workflows/validate.yml
- name: Validate Clerk Config
  run: |
    python3 scripts/validate.py \
      --root . \
      --strict \
      --ci

Integration

• nextjs-validator - Validates Next.js 16 (proxy.ts)
• biome-validator - Validates linting config
• git-safety - Ensures no secrets committed