Social login

Social Login - Google & Apple Sign-In

Google and Apple authentication with Supabase or custom backend.

When to Use This Skill

• Adding social login to a project
• Configuring OAuth providers (Google Cloud, Apple Developer)
• Troubleshooting social auth issues
• Adding SHA-1 fingerprints for Android

Reference Files

reference/
├── repositories/     # Domain interface, impl, mocks
├── failures/         # Sealed Failure types
├── providers/        # AuthNotifier social methods
├── utils/            # Nonce helpers, constants
├── widgets/          # Social login button
└── screens/          # OAuth callback (Android)

templates/            # Info.plist, AndroidManifest additions

See: implementation-guide.md for complete file list.

Workflow

Phase 1: Provider Setup

1. Google Cloud Console - OAuth clients, SHA-1 (see google-guide.md)
2. Apple Developer - App ID, Service ID, Key (see apple-guide.md)
3. Supabase - Enable providers (see supabase-guide.md)

Phase 2: Platform Config

1. iOS: Add URL schemes to Info.plist, add Sign in with Apple capability
2. Android: Add deep link intent filter to AndroidManifest.xml

Phase 3: Implementation

1. Copy reference files to project
2. Add methods to existing AuthRepositoryImpl
3. Add provider methods to AuthNotifier
4. Add OAuth callback route
5. Run /i18n for strings

Core API

// Google Sign-In
final result = await repository.signInWithGoogle();

// Apple Sign-In
final result = await repository.signInWithApple();

// Result contains: userId, email?, displayName?, isNewUser

Failure Types

Type	When	UI Action
GoogleSignInCancelledFailure	User dismissed	Silent
GoogleSignInFailedFailure	SDK error	Error + retry
AppleSignInCancelledFailure	User dismissed	Silent
AppleSignInFailedFailure	SDK error	Error + retry
TokenValidationFailure	Invalid token	Error + retry
SocialAuthNetworkFailure	Connection	Retry button

Cancellation is NOT an error - handle silently.

Platform Flows

Provider	iOS	Android
Google	Native SDK	Native SDK
Apple	Native SDK	OAuth Browser

SHA-1 Fingerprints

cd android && ./gradlew signingReport

Add to Google Cloud Console: debug, release, Play Store SHA-1.

Guides

File	Content
google-guide.md	Google Cloud Console setup
apple-guide.md	Apple Developer setup
supabase-guide.md	Supabase provider config
implementation-guide.md	Step-by-step code
checklist.md	Verification checklist

Common Issues

Error	Cause	Solution
DEVELOPER_ERROR	SHA-1 mismatch	Add correct SHA-1
No idToken	Missing serverClientId	Set GOOGLE_WEB_CLIENT_ID
invalid_client	Apple config wrong	Check Supabase Apple config
No callback (Android)	Deep link wrong	Verify AndroidManifest

Checklist

• Google Cloud Console: OAuth client IDs created (iOS, Android, Web)
• Android: All SHA-1 fingerprints added (debug, release, Play Store)
• Apple Developer: App ID with Sign in with Apple enabled
• Apple Developer: Service ID configured (for Android OAuth flow)
• Supabase: Google and Apple providers enabled with credentials
• iOS: URL schemes added to Info.plist
• iOS: Sign in with Apple capability added
• Android: Deep link intent filter in AndroidManifest.xml
• OAuth callback route added to router
• Cancellation handled silently (not shown as error)
• build_runner executed successfully

Related Skills

• /phone-auth - Can combine with social login
• /i18n - Localized strings
• /release - iOS capabilities, Android signing
• /testing - Test social login flows