Auth0 Migration Guide Migrate users and authentication flows from existing auth providers to Auth0. 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 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: Migrating to Auth0 (replace existing auth) Adding Auth0 alongside (keep both temporarily) Starting fresh (remove old auth, new Auth0 setup) 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 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 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 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 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 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 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