auth0-migration

name	auth0-migration
description	Use when migrating from existing auth providers (Firebase, Cognito, Supabase, custom auth) to Auth0 - covers bulk user import, gradual migration strategies, code migration patterns, and JWT validation updates

Auth0 Migration Guide

Migrate users and authentication flows from existing auth providers to Auth0.

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Overview

When to Use This Skill

• Migrating from another auth provider to Auth0
• Bulk importing existing users
• Gradually transitioning active user bases
• Updating JWT validation in APIs

When NOT to Use

• Starting fresh with Auth0 - Use auth0-quickstart for new projects without existing users
• Already using Auth0 - This is for migrating TO Auth0, not between Auth0 tenants
• Only adding MFA or features - Use feature-specific skills if just adding capabilities

Migration Approaches

• Bulk Migration: One-time user import (recommended for small/inactive bases)
• Gradual Migration: Lazy migration over time (recommended for large active bases)
• Hybrid: Import inactive users, lazy-migrate active users

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Step 0: Detect Existing Auth Provider

Check if the project already has authentication:

Search for common auth-related patterns in the codebase:

Pattern	Indicates
signInWithEmailAndPassword, onAuthStateChanged	Firebase Auth
useUser, useSession, isSignedIn	Existing auth hooks
passport.authenticate, LocalStrategy	Passport.js
authorize, getAccessToken, oauth	OAuth/OIDC
JWT, jwt.verify, jsonwebtoken	Token-based auth
/api/auth/, /login, /callback	Auth routes

If existing auth detected, ask:

I detected existing authentication in your project. Are you:

1. Migrating to Auth0 (replace existing auth)
2. Adding Auth0 alongside (keep both temporarily)
3. Starting fresh (remove old auth, new Auth0 setup)

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Migration Workflow

Step 1: Export Existing Users

Export users from your current provider. See User Import Guide for detailed instructions:

• Exporting from Firebase
• Exporting from AWS Cognito
• Exporting from Supabase
• Exporting from Custom Database

Required data per user:

• Email address
• Email verified status
• Password hash (if available)
• User metadata/profile data
• Creation timestamp

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Step 2: Import Users to Auth0

Import users via Dashboard, CLI, or Management API.

Quick start:

# Via Auth0 CLI
auth0 api post "jobs/users-imports" \
  --data "connection_id=con_ABC123" \
  --data "users=@users.json"

For detailed instructions:

• User JSON Format
• Password Hash Algorithms
• Import Methods
• Monitoring Import Progress
• Common Import Errors

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Step 3: Migrate Application Code

Update your application code to use Auth0 SDKs.

See Code Migration Patterns for detailed before/after examples:

Frontend:

• React Migration
• Next.js Migration
• Vue.js Migration
• Angular Migration
• React Native Migration

Backend:

• Express.js Migration
• API JWT Validation

Provider-Specific:

• Firebase to Auth0
• Supabase to Auth0
• Clerk to Auth0

After migrating code, use framework-specific skills:

• auth0-react for React applications
• auth0-nextjs for Next.js applications
• auth0-vue for Vue.js applications
• auth0-angular for Angular applications
• auth0-express for Express.js applications
• auth0-react-native for React Native/Expo applications

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Step 4: Update API JWT Validation

If your API validates JWTs, update to validate Auth0 tokens.

Key differences:

• Algorithm: HS256 (symmetric) → RS256 (asymmetric)
• Issuer: Custom → https://YOUR_TENANT.auth0.com/
• JWKS URL: https://YOUR_TENANT.auth0.com/.well-known/jwks.json

See JWT Validation Examples for:

• Node.js / Express implementation
• Python / Flask implementation
• Key differences and migration checklist

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Gradual Migration Strategy

For production applications with active users, use a phased approach:

Phase 1: Parallel Auth

Support both Auth0 and legacy provider simultaneously:

// Support both providers during migration
const getUser = async () => {
  // Try Auth0 first
  const auth0User = await getAuth0User();
  if (auth0User) return auth0User;

  // Fall back to legacy provider
  return await getLegacyUser();
};

Phase 2: New Users on Auth0

• All new signups go to Auth0
• Existing users continue on legacy provider
• Migrate users on next login (lazy migration)

Phase 3: Forced Migration

• Prompt remaining users to "update account"
• Send password reset emails via Auth0
• Set deadline for legacy system shutdown

Phase 4: Cleanup

• Remove legacy auth code
• Archive user export for compliance
• Update documentation

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Common Migration Issues

Issue	Solution
Password hashes incompatible	Use Auth0 custom DB connection with lazy migration
Social logins don't link	Configure same social connection, users auto-link by email
Custom claims missing	Add claims via Auth0 Actions
Token format different	Update API to validate RS256 JWTs with Auth0 issuer
Session persistence	Auth0 uses rotating refresh tokens; update token storage
Users must re-login	Expected for redirect-based auth; communicate to users

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Reference Documentation

User Import

Complete guide to exporting and importing users:

• Exporting from Common Providers
• User JSON Format
• Password Hash Algorithms
• Import Methods
• Monitoring & Troubleshooting

Code Migration

Before/after examples for all major frameworks:

• React Patterns
• Next.js Patterns
• Express Patterns
• Vue.js Patterns
• Angular Patterns
• React Native Patterns
• API JWT Validation

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Related Skills

Core Integration

• auth0-quickstart - Initial Auth0 setup after migration

SDK Skills

• auth0-react - React SPA integration
• auth0-nextjs - Next.js integration
• auth0-vue - Vue.js integration
• auth0-angular - Angular integration
• auth0-express - Express.js integration
• auth0-react-native - React Native/Expo integration

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References

• Auth0 User Migration Documentation
• Bulk User Import
• Password Hash Algorithms
• Management API - User Import