clerk-webhooks

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.

Keep the Webhook Route Unprotected

Webhook deliveries carry no user session. verifyWebhook() is the only check the route needs. A bare clerkMiddleware() protects nothing, so the route is already reachable. Don't call auth.protect() for /api/webhooks(.*), in middleware or in the handler. A project that does returns 404 for every delivery until that call is removed. See Ensure the webhook route is public.

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: '[email protected]',
      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 })
}

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
401 or 404 on every delivery	auth.protect() covers the webhook route (in middleware or in the handler)	Remove that check; verifyWebhook() is the only check the route needs
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/verify for local webhook testing
• clerk-setup - Initial Clerk install
• clerk-orgs - Org membership events
• clerk-billing - Subscription, subscription item, and payment attempt events
• clerk-backend-api - Sync via direct API calls