clerk-data-handling

Clerk Data Handling

Overview

Manage user data, implement privacy features, and ensure GDPR/CCPA compliance using the Clerk Backend API. Covers data export, right to be forgotten, consent management, and audit logging.

Prerequisites

• Clerk integration working
• Understanding of GDPR/CCPA requirements
• Database with user-related data linked by Clerk user IDs

Instructions

Step 1: User Data Export

// app/api/privacy/export/route.ts
import { auth, clerkClient } from '@clerk/nextjs/server'

export async function GET() {
  const { userId } = await auth()
  if (!userId) return Response.json({ error: 'Unauthorized' }, { status: 401 })

  const client = await clerkClient()
  const clerkUser = await client.users.getUser(userId)

  // Gather data from Clerk
  const clerkData = {
    id: clerkUser.id,
    emails: clerkUser.emailAddresses.map((e) => e.emailAddress),
    firstName: clerkUser.firstName,
    lastName: clerkUser.lastName,
    createdAt: clerkUser.createdAt,
    lastSignInAt: clerkUser.lastSignInAt,
    publicMetadata: clerkUser.publicMetadata,
  }

  // Gather data from your database
  const appData = await db.user.findUnique({
    where: { clerkId: userId },
    include: { posts: true, comments: true, preferences: true },
  })

  return Response.json({
    exportDate: new Date().toISOString(),
    clerkProfile: clerkData,
    applicationData: appData,
  })
}

Step 2: User Deletion (Right to be Forgotten)

// app/api/privacy/delete/route.ts
import { auth, clerkClient } from '@clerk/nextjs/server'

export async function DELETE() {
  const { userId } = await auth()
  if (!userId) return Response.json({ error: 'Unauthorized' }, { status: 401 })

  const deletionLog: { step: string; status: string }[] = []

  try {
    // 1. Delete application data first
    await db.comment.deleteMany({ where: { authorId: userId } })
    deletionLog.push({ step: 'comments', status: 'deleted' })

    await db.post.deleteMany({ where: { authorId: userId } })
    deletionLog.push({ step: 'posts', status: 'deleted' })

    await db.user.delete({ where: { clerkId: userId } })
    deletionLog.push({ step: 'app_user', status: 'deleted' })

    // 2. Delete from Clerk (this ends the session)
    const client = await clerkClient()
    await client.users.deleteUser(userId)
    deletionLog.push({ step: 'clerk_user', status: 'deleted' })

    // 3. Log deletion for compliance audit trail
    await db.auditLog.create({
      data: {
        action: 'USER_DELETED',
        subjectId: userId,
        details: JSON.stringify(deletionLog),
        timestamp: new Date(),
      },
    })

    return Response.json({ deleted: true, log: deletionLog })
  } catch (error) {
    return Response.json({ error: 'Partial deletion', log: deletionLog }, { status: 500 })
  }
}

Step 3: Consent Management with Metadata

// lib/consent.ts
import { clerkClient } from '@clerk/nextjs/server'

interface ConsentRecord {
  marketing: boolean
  analytics: boolean
  thirdParty: boolean
  updatedAt: string
}

export async function updateConsent(userId: string, consent: Partial<ConsentRecord>) {
  const client = await clerkClient()
  const user = await client.users.getUser(userId)
  const existing = (user.publicMetadata.consent as ConsentRecord) || {}

  const updated: ConsentRecord = {
    ...existing,
    ...consent,
    updatedAt: new Date().toISOString(),
  }

  await client.users.updateUser(userId, {
    publicMetadata: { ...user.publicMetadata, consent: updated },
  })

  return updated
}

export async function getConsent(userId: string): Promise<ConsentRecord | null> {
  const client = await clerkClient()
  const user = await client.users.getUser(userId)
  return (user.publicMetadata.consent as ConsentRecord) || null
}

Step 4: Consent UI Component

'use client'
import { useUser } from '@clerk/nextjs'
import { useState } from 'react'

export function ConsentManager() {
  const { user } = useUser()
  const consent = (user?.publicMetadata as any)?.consent || {}
  const [marketing, setMarketing] = useState(consent.marketing ?? false)
  const [analytics, setAnalytics] = useState(consent.analytics ?? true)

  const saveConsent = async () => {
    await fetch('/api/privacy/consent', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ marketing, analytics }),
    })
  }

  return (
    <div>
      <h3>Privacy Preferences</h3>
      <label>
        <input type="checkbox" checked={marketing} onChange={(e) => setMarketing(e.target.checked)} />
        Marketing communications
      </label>
      <label>
        <input type="checkbox" checked={analytics} onChange={(e) => setAnalytics(e.target.checked)} />
        Analytics tracking
      </label>
      <button onClick={saveConsent}>Save Preferences</button>
    </div>
  )
}

Step 5: Audit Logging via Webhooks

// app/api/webhooks/clerk/route.ts (audit section)
async function logAuditEvent(evt: WebhookEvent) {
  const auditEntry = {
    eventType: evt.type,
    userId: 'user_id' in evt.data ? evt.data.user_id : evt.data.id,
    timestamp: new Date().toISOString(),
    metadata: JSON.stringify(evt.data),
  }

  await db.auditLog.create({ data: auditEntry })

  // Track compliance-relevant events
  if (['user.deleted', 'user.updated'].includes(evt.type)) {
    console.log(`[COMPLIANCE] ${evt.type} for user ${auditEntry.userId}`)
  }
}

Output

• Data export API returning Clerk profile + application data
• User deletion cascade (app data, then Clerk, then audit log)
• Consent management stored in Clerk publicMetadata
• Privacy preferences UI component
• Audit logging for compliance events

Error Handling

Scenario	Action
Partial deletion failure	Log completed steps, retry failed services, alert ops team
Export timeout on large data	Queue export job, email user download link when ready
Consent sync failure	Retry with exponential backoff, fall back to local storage
Clerk API rate limit on bulk delete	Batch deletions with delays between requests

Examples

Bulk User Data Cleanup Script

// scripts/cleanup-orphaned-users.ts
import { createClerkClient } from '@clerk/backend'

const clerk = createClerkClient({ secretKey: process.env.CLERK_SECRET_KEY! })

async function cleanupOrphanedDbUsers() {
  const dbUsers = await db.user.findMany({ select: { clerkId: true } })

  for (const dbUser of dbUsers) {
    try {
      await clerk.users.getUser(dbUser.clerkId)
    } catch (err: any) {
      if (err.status === 404) {
        console.log(`Orphaned user: ${dbUser.clerkId} — removing from DB`)
        await db.user.delete({ where: { clerkId: dbUser.clerkId } })
      }
    }
  }
}

Resources

• Clerk User API
• Clerk Metadata
• GDPR Compliance Guide

Next Steps

Proceed to clerk-enterprise-rbac for enterprise SSO and RBAC.