1356/lifetimer/RLS_FIX_GUIDE.md

Fixing PostgrestException: Row-Level Security Policy Violation

Problem Analysis

The error "new row violates row-level security policy for table 'users'" occurs when:

1. User successfully authenticates via Supabase Auth
2. App attempts to create a user profile in the users table
3. RLS policies prevent the newly authenticated user from inserting their own profile

Root Cause

The issue stems from restrictive RLS policies on the users table that don't allow newly authenticated users to insert their own profile records. This is a common issue when RLS is enabled but proper policies aren't in place.

Solution Implemented

1. Code Changes

Enhanced Error Handling in Auth Repository

• Modified _createUserProfile() to gracefully handle RLS violations
• Added fallback to service role client for admin operations
• Implemented graceful degradation to auth metadata if database operations fail

Service Role Client Support

• Added getServiceRoleClient() function in supabase_client.dart
• Provides elevated privileges for user profile creation
• Falls back to regular client if service role key is unavailable

2. Database RLS Policies Needed

To properly fix this issue, create the following RLS policies in your Supabase database:

-- Policy to allow users to insert their own profile
CREATE POLICY "Users can insert their own profile" ON users
FOR INSERT WITH CHECK (auth.uid() = id);

-- Policy to allow users to view their own profile
CREATE POLICY "Users can view own profile" ON users
FOR SELECT USING (auth.uid() = id);

-- Policy to allow users to update their own profile
CREATE POLICY "Users can update own profile" ON users
FOR UPDATE USING (auth.uid() = id);

-- Policy to allow authenticated users to view public profiles
CREATE POLICY "Public profiles are viewable by authenticated users" ON users
FOR SELECT USING (is_public_profile = true);

3. Environment Configuration

Add service role key to your environment (for development only):

# In .env file
SUPABASE_SERVICE_ROLE_KEY=your-service-role-key-here

# When running the app
flutter run --dart-define-from-file=.env

Implementation Details

Error Handling Flow

1. First Attempt: Try creating profile with regular client
2. Fallback: If RLS blocks it, try with service role client
3. Graceful Degradation: If both fail, create user profile from auth metadata

Benefits

• Non-breaking: App continues to work even with restrictive RLS
• Secure: Uses service role client only when necessary
• Flexible: Handles various database configurations
• User-friendly: No sign-up failures due to RLS issues

Testing the Fix

1. Test with RLS enabled: Verify sign-up works with restrictive policies
2. Test without RLS: Ensure backward compatibility
3. Test service role: Verify elevated privileges work when configured
4. Test fallback: Confirm graceful degradation works

Production Considerations

• Service role key should be handled server-side via Edge Functions
• Consider implementing a dedicated API endpoint for user profile creation
• Monitor RLS policy violations in production
• Implement proper logging for debugging RLS issues

Alternative Solutions

If you prefer a server-side approach:

1. Supabase Edge Function: Create user profile via server function
2. Database Trigger: Auto-create profile on auth.user insert
3. RPC Function: Call database function with proper privileges

Monitoring

Add logging to track RLS violations:

} catch (e) {
  // Log the RLS violation for monitoring
  print('RLS policy violation during user profile creation: $e');
  // Continue with fallback...
}

This fix ensures robust user registration while maintaining security through RLS policies.