Troubleshoot common Clerk errors and issues. Use when encountering authentication errors, SDK issues, or configuration problems with Clerk. Trigger with phrases like "clerk error", "clerk not working", "clerk authentication failed", "clerk issue", "fix clerk".
/plugin marketplace add jeremylongshore/claude-code-plugins-plus-skills/plugin install clerk-pack@claude-code-plugins-plusThis skill is limited to using the following tools:
Diagnose and resolve common Clerk authentication errors and issues.
Error: Clerk: Invalid API key
Cause: Publishable or secret key is incorrect or mismatched. Solution:
# Verify keys in .env.local match Clerk dashboard
# Publishable key starts with pk_test_ or pk_live_
# Secret key starts with sk_test_ or sk_live_
# Check for trailing whitespace
cat -A .env.local | grep CLERK
# Ensure correct environment
echo $NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY
Error: useAuth can only be used within the <ClerkProvider /> component
Cause: Component using Clerk hooks is outside ClerkProvider. Solution:
// Ensure ClerkProvider wraps entire app in layout.tsx
import { ClerkProvider } from '@clerk/nextjs'
export default function RootLayout({ children }) {
return (
<ClerkProvider>
<html><body>{children}</body></html>
</ClerkProvider>
)
}
Error: Session not found
Cause: User session expired or was revoked. Solution:
// Handle gracefully in your app
const { userId } = await auth()
if (!userId) {
redirect('/sign-in')
}
Error: form_identifier_not_found
Cause: Email/username not registered. Solution:
// Show helpful message to user
catch (err: any) {
if (err.errors?.[0]?.code === 'form_identifier_not_found') {
setError('No account found with this email. Please sign up.')
}
}
Error: form_password_incorrect
Cause: Wrong password entered. Solution:
catch (err: any) {
if (err.errors?.[0]?.code === 'form_password_incorrect') {
setError('Incorrect password. Try again or reset your password.')
}
}
Error: Too many redirects
Cause: Middleware matcher includes sign-in page. Solution:
// middleware.ts
const isPublicRoute = createRouteMatcher([
'/sign-in(.*)', // Must include sign-in pages
'/sign-up(.*)',
'/'
])
export default clerkMiddleware(async (auth, request) => {
if (!isPublicRoute(request)) {
await auth.protect()
}
})
Error: Routes not protected
Cause: Matcher not matching routes correctly. Solution:
export const config = {
matcher: [
// Skip static files and _next
'/((?!_next|[^?]*\\.(?:html?|css|js|jpe?g|webp|png|gif|svg|ttf|woff2?|ico)).*)',
'/',
'/(api|trpc)(.*)'
]
}
Error: Text content does not match server-rendered HTML
Cause: Auth state differs between server and client. Solution:
'use client'
import { useUser } from '@clerk/nextjs'
export function UserGreeting() {
const { user, isLoaded } = useUser()
// Prevent hydration mismatch by waiting for load
if (!isLoaded) {
return <div>Loading...</div>
}
return <div>Hello, {user?.firstName}</div>
}
Error: Cannot read properties of undefined (reading 'userId')
Cause: Using auth() in client component or non-server context. Solution:
// Server Component - use auth()
import { auth } from '@clerk/nextjs/server'
const { userId } = await auth()
// Client Component - use useAuth()
'use client'
import { useAuth } from '@clerk/nextjs'
const { userId } = useAuth()
Error: Webhook signature verification failed
Cause: Incorrect webhook secret or missing headers. Solution:
// app/api/webhooks/clerk/route.ts
import { Webhook } from 'svix'
import { headers } from 'next/headers'
export async function POST(req: Request) {
const WEBHOOK_SECRET = process.env.CLERK_WEBHOOK_SECRET!
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')
const body = await req.text()
const wh = new Webhook(WEBHOOK_SECRET)
const evt = wh.verify(body, {
'svix-id': svix_id!,
'svix-timestamp': svix_timestamp!,
'svix-signature': svix_signature!
})
// Process event
}
# Check Clerk version
npm list @clerk/nextjs
# Verify environment variables
npx next info
# Check for multiple Clerk instances
npm list | grep clerk
# Clear Next.js cache
rm -rf .next && npm run dev
| Error Code | Meaning | Quick Fix |
|---|---|---|
form_identifier_not_found | User doesn't exist | Show sign-up link |
form_password_incorrect | Wrong password | Show reset link |
session_exists | Already logged in | Redirect to app |
verification_expired | Code expired | Resend code |
rate_limit_exceeded | Too many attempts | Wait and retry |
Proceed to clerk-debug-bundle for comprehensive debugging tools.