Troubleshooting Login Issues on Vercel Deployment
If you're unable to log in to your existing account and use calculations after deploying to Vercel, here are several steps to diagnose and fix the issue:
1. Check Environment Variables
First, ensure all required environment variables are correctly set in your Vercel project:
- Go to your Vercel dashboard
- Select your project
- Click on "Settings" > "Environment Variables"
Verify these essential variables are present and correct:
NEXT_PUBLIC_SUPABASE_URLNEXT_PUBLIC_SUPABASE_ANON_KEYSUPABASE_SERVICE_ROLE_KEY (if used)- Any other environment variables your app requires
2. Check Supabase Configuration
URL Restrictions
- Go to your Supabase dashboard
- Navigate to Authentication > URL Configuration
- Add your Vercel deployment URL to the "Site URL" field
- Add your Vercel domain to the "Redirect URLs" list (e.g.,
https://your-app.vercel.app/auth/callback)
CORS Settings
- In Supabase dashboard, go to API Settings
- Under "API Settings", check "CORS (Cross-Origin Resource Sharing)"
- Add your Vercel domain to the allowed origins (e.g.,
https://your-app.vercel.app)
3. Implement a Debug Page
Let's add a simple debug page to help diagnose issues:
4. Modify Supabase Client for Better Error Handling
Let's update the Supabase client to provide better error handling and logging:
5. Improve Auth Provider with Better Error Handling
6. Additional Steps to Take
Check Database Schema
- Ensure your database schema in production matches your development environment
Verify that all required tables exist:
user_profilescalculation_typescalculation_history
Create a Test User
If you're having trouble with existing accounts, try creating a new test user:
- Go to your Supabase dashboard
- Navigate to Authentication > Users
- Click "Add User" and create a test account
- Try logging in with this test account
Check RLS Policies
- In Supabase dashboard, go to Database > Tables
- For each table, check the "RLS Policies" tab
- Ensure appropriate policies are in place to allow authenticated users to access data
7. Using the Connection Debug Page
After deploying these changes:
- Navigate to
/auth/connection-debug on your deployed site This page will show you:
- If environment variables are correctly set
- If the connection to Supabase is working
- If your database tables are accessible
- How many records exist in key tables
This information will help pinpoint exactly where the issue is occurring.
8. Common Issues and Solutions
"Failed to fetch" errors
- Check your CORS settings in Supabase
- Verify your Supabase URL is correct
- Ensure your Supabase project is active and not in maintenance mode
Authentication issues
- Check if email confirmation is required in your Supabase settings
- Verify the Site URL in Supabase Authentication settings matches your Vercel URL
- Try clearing browser cookies and local storage
Database access issues
- Check Row Level Security (RLS) policies
- Verify the database is not in read-only mode
- Ensure your Supabase service role key has appropriate permissions
Let me know the results from the connection debug page, and I can provide more specific guidance based on what it shows!