
Description
Clerk webhooks for real-time events and data syncing. Verify with verifyWebhook from the framework-specific package. Handle user, session, organization, billing, and payment events. Build event-driven features like database sync, notifications, and integrations.
SKILL.md
Webhooks
Output complete, working webhook handlers with verifyWebhook(req) verification in every handler.
When to Use Webhooks
Webhooks are asynchronous and eventually consistent. Delivery is fast but not guaranteed to be immediate, and may occasionally fail (Svix retries on a fixed schedule). Use them for:
- Database sync (a separate users / orgs table that follows Clerk)
- Notifications (welcome emails, Slack pings, internal alerts)
- Integrations triggered by lifecycle events
Do NOT rely on webhook delivery as part of a synchronous flow such as onboarding ("user signs up, then we read X from our DB"). For data the user just created, read it from the Clerk session token or call the Backend API directly. Webhooks fill the gap when you need data about other users or events the session token doesn't carry.
Verify Every Webhook
Use verifyWebhook(req) from the framework-specific package (@clerk/nextjs/webhooks, @clerk/express/webhooks, etc.). It reads CLERK_WEBHOOK_SIGNING_SECRET automatically and throws on bad signatures. Skipping verification, even for notification-only handlers, exposes the endpoint to spoofed events.
Make the Webhook Route Public
Webhook routes must be excluded from Clerk middleware protection. Without this, Clerk returns 401.
// proxy.ts (Next.js <=15: middleware.ts)
import { clerkMiddleware, createRouteMatcher } from '@clerk/nextjs/server'
const isPublicRoute = createRouteMatcher(['/api/webhooks(.*)'])
export default clerkMiddleware(async (auth, req) => {
if (!isPublicRoute(req)) await auth.protect()
})
Complete Webhook Handler (Next.js App Router)
// app/api/webhooks/route.ts
import { verifyWebhook } from '@clerk/nextjs/webhooks'
import { NextRequest } from 'next/server'
import { db } from '@/lib/db'
export async function POST(req: NextRequest) {
// ALWAYS verify - never skip, even for notification-only handlers
let evt
try {
evt = await verifyWebhook(req) // uses CLERK_WEBHOOK_SIGNING_SECRET automatically
} catch (err) {
console.error('Webhook verification failed:', err)
return new Response('Verification failed', { status: 400 })
}
if (evt.type === 'user.created') {
const { id, email_addresses, first_name, last_name } = evt.data
const email = email_addresses[0]?.email_address
const name = `${first_name ?? ''} ${last_name ?? ''}`.trim()
await db.users.create({ data: { clerkId: id, email, name } })
}
if (evt.type === 'user.updated') {
const { id, email_addresses, first_name, last_name } = evt.data
const email = email_addresses[0]?.email_address
await db.users.update({ where: { clerkId: id }, data: { email, first_name, last_name } })
}
if (evt.type === 'user.deleted') {
const { id } = evt.data
await db.users.delete({ where: { clerkId: id } })
}
if (evt.type === 'organizationMembership.created') {
const { organization, public_user_data, role } = evt.data
const orgId = organization.id
const userId = public_user_data.user_id
await db.teamMembers.create({ data: { orgId, userId, role } })
}
if (evt.type === 'organizationMembership.deleted') {
const { organization, public_user_data } = evt.data
const orgId = organization.id
const userId = public_user_data.user_id
await db.teamMembers.delete({ where: { orgId_userId: { orgId, userId } } })
}
return new Response('OK', { status: 200 })
}
Full Example: Welcome Email (Resend) + Slack Notification on user.created
Notification-only handlers still verify the signature. Same pattern as the database-sync handler:
// app/api/webhooks/route.ts
import { verifyWebhook } from '@clerk/nextjs/webhooks'
import { NextRequest } from 'next/server'
import { Resend } from 'resend'
const resend = new Resend(process.env.RESEND_API_KEY)
export async function POST(req: NextRequest) {
// Step 1: ALWAYS verify the webhook signature - NEVER skip this
let evt
try {
evt = await verifyWebhook(req) // uses CLERK_WEBHOOK_SIGNING_SECRET env var
} catch (err) {
console.error('Webhook verification failed:', err)
return new Response('Verification failed', { status: 400 })
}
// Step 2: Listen for user.created event
if (evt.type === 'user.created') {
// Step 3: Extract user email and name from webhook payload
const { id, email_addresses, first_name, last_name } = evt.data
const email = email_addresses[0]?.email_address
const name = `${first_name ?? ''} ${last_name ?? ''}`.trim()
// Step 4: Call Resend API to send welcome email
await resend.emails.send({
from: 'noreply@yourdomain.com',
to: email,
subject: 'Welcome!',
html: `<p>Hi ${name}, welcome to our app!</p>`,
})
// Step 5: Post notification to Slack channel
await fetch(process.env.SLACK_WEBHOOK_URL!, {
method: 'POST',
headers: { 'Content-Type': 'application/json' },
body: JSON.stringify({
text: `New user signed up: ${name} (${email})`,
}),
})
}
// Always return 200 to acknowledge receipt
return new Response('OK', { status: 200 })
}
Also include proxy.ts (Next.js <=15: middleware.ts) to make the route public:
// proxy.ts (Next.js <=15: middleware.ts)
import { clerkMiddleware, createRouteMatcher } from '@clerk/nextjs/server'
const isPublicRoute = createRouteMatcher(['/api/webhooks(.*)'])
export default clerkMiddleware(async (auth, req) => {
if (!isPublicRoute(req)) await auth.protect()
})
Full Example: Organization Membership Sync to Database
// app/api/webhooks/route.ts
import { verifyWebhook } from '@clerk/nextjs/webhooks'
import { NextRequest } from 'next/server'
import { db } from '@/lib/db' // your database client
export async function POST(req: NextRequest) {
// ALWAYS verify signature - never skip, even for simple handlers
let evt
try {
evt = await verifyWebhook(req) // uses CLERK_WEBHOOK_SIGNING_SECRET env var
} catch (err) {
console.error('Webhook verification failed:', err)
return new Response('Verification failed', { status: 400 })
}
if (evt.type === 'organization.created') {
const { id, name } = evt.data
await db.workspaces.create({
data: { orgId: id, name, createdAt: new Date() },
})
}
if (evt.type === 'organizationMembership.created') {
// Extract organization ID, user ID, and role from payload
const { organization, public_user_data, role } = evt.data
const orgId = organization.id
const userId = public_user_data.user_id
// Add to team_members table
await db.team_members.create({
data: { orgId, userId, role },
})
// Create workspace record for new member
await db.workspaces.create({
data: { orgId, userId, createdAt: new Date() },
})
}
if (evt.type === 'organizationMembership.deleted') {
// Extract organization ID and user ID from payload
const { organization, public_user_data } = evt.data
const orgId = organization.id
const userId = public_user_data.user_id
// Remove from team_members table
await db.team_members.delete({
where: { orgId, userId },
})
// Remove workspace record
await db.workspaces.deleteMany({
where: { orgId, userId },
})
}
// Return 200 status on success
return new Response('OK', { status: 200 })
}
Other Frameworks
For Express, Astro, Fastify, Nuxt, React Router, and TanStack Start, use the framework-specific verifyWebhook adapter. Each Clerk SDK package ships its own (@clerk/express/webhooks, @clerk/astro/webhooks, @clerk/fastify/webhooks, etc.).
See references/frameworks.md for full handler examples per framework.
Type Narrowing for evt.data
verifyWebhook returns WebhookEvent, a discriminated union of all event types. Narrow with evt.type to get type-safe access to evt.data:
const evt = await verifyWebhook(req)
if (evt.type === 'user.created') {
// evt.data is now UserJSON, autocompletes id, email_addresses, etc.
console.log(evt.data.id)
}
For manual typing of nested payloads, import the JSON types from your framework's webhook subpath: DeletedObjectJSON, EmailJSON, OrganizationInvitationJSON, OrganizationJSON, OrganizationMembershipJSON, SessionJSON, SMSMessageJSON, UserJSON.
Payload Field Reference
User events (user.created, user.updated, user.deleted)
const {
id, // Clerk user ID
email_addresses, // array; [0].email_address is primary email
first_name,
last_name,
image_url,
public_metadata,
} = evt.data
Organization events (organization.created, organization.updated, organization.deleted)
const {
id, // org ID
name, // org name
slug,
} = evt.data
Organization Membership events (organizationMembership.created, organizationMembership.updated, organizationMembership.deleted)
const {
organization, // { id, name, ... }
public_user_data, // { user_id, first_name, last_name, ... }
role, // e.g. 'org:admin', 'org:member'
} = evt.data
// Access: organization.id, public_user_data.user_id, role
Supported Events (Full Catalog)
User: user.created user.updated user.deleted
Session: session.created session.ended session.removed session.revoked
Organization: organization.created organization.updated organization.deleted
Organization Membership: organizationMembership.created organizationMembership.updated organizationMembership.deleted
Organization Domain: organizationDomain.created organizationDomain.updated organizationDomain.deleted
Organization Invitation: organizationInvitation.accepted organizationInvitation.created organizationInvitation.revoked
Communication: email.created sms.created
Waitlist: waitlistEntry.created waitlistEntry.updated
Permission: permission.created permission.updated permission.deleted
Role: role.created role.updated role.deleted
Subscription: subscription.created subscription.updated subscription.active subscription.pastDue
Subscription Item: subscriptionItem.created subscriptionItem.active subscriptionItem.updated subscriptionItem.canceled subscriptionItem.upcoming subscriptionItem.ended subscriptionItem.abandoned subscriptionItem.incomplete subscriptionItem.pastDue subscriptionItem.freeTrialEnding
Payment: paymentAttempt.created paymentAttempt.updated
Webhook Reliability
Retries: Svix retries failed webhooks on a set schedule (see Svix Retry Schedule). Return 2xx to succeed, 4xx/5xx to retry. Use the svix-id header as an idempotency key to deduplicate retried events.
Replay: Failed webhooks can be replayed from Dashboard.
Common Pitfalls
| Symptom | Cause | Fix |
|---|---|---|
| Verification fails (Next.js) | Wrong import or usage | Use @clerk/nextjs/webhooks, pass req directly |
| Verification fails (Express) | Using express.json() | Use express.raw({ type: 'application/json' }) for webhook route |
| Route not found (404) | Wrong path | Use /api/webhooks or preserve existing path |
| Not authorized (401) | Route is protected by middleware | Make route public in clerkMiddleware() |
| No data in DB | Async job pending | Wait/check logs |
| Duplicate entries | Only handling user.created | Also handle user.updated |
| Timeouts | Handler too slow | Queue async work, return 200 first |
Testing & Deployment
Local: Use the Clerk CLI's first-party tunnel — no auth or linked project needed:
clerk webhooks listen --token "$(clerk webhooks token)" --forward-to http://localhost:3000/api/webhooks
Add the printed relay URL (https://webhooks.clerk.com/in/c_.../) as a webhook endpoint in the Dashboard — events don't flow until you do. svix-* headers are preserved, so verifyWebhook() works against that endpoint's signing secret as usual. Flags, offline signature checks (clerk webhooks verify), and agent-mode behavior are in the clerk-cli skill. Without the CLI, tunnel localhost:3000 yourself (ngrok, localtunnel, Cloudflare Tunnel) and add the public URL to the Dashboard endpoint.
Production: Update webhook endpoint URL to production domain. Copy CLERK_WEBHOOK_SIGNING_SECRET to production env vars.
References
| Reference | Description |
|---|---|
references/frameworks.md | Webhook handler examples for Express, Astro, Fastify, Nuxt, React Router, TanStack Start |
See Also
clerk-cli-clerk webhooks listen/verifyfor local webhook testingclerk-setup- Initial Clerk installclerk-orgs- Org membership eventsclerk-billing- Subscription, subscription item, and payment attempt eventsclerk-backend-api- Sync via direct API calls
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