Replit + Supabase Security
Replit's collaborative environment is great for building with Supabase, but credential management and public Repls require extra attention.
Why Replit + Supabase?
Replit's easy deployment and Supabase's generous free tier make this a popular combo for learning and prototypes. The public nature of free Repls creates unique security challenges.
Common Vulnerabilities
These are the security issues we find most often in Replit apps using Supabase.
Credentials in Public Repls
Free Repls are public by default, potentially exposing Supabase service keys in source code.
Secrets Not Used Properly
Developers may hardcode credentials instead of using Replit's Secrets feature.
Missing RLS Configuration
Like other platforms, RLS is often skipped during rapid development.
Environment Confusion
Development and production may share credentials, increasing exposure risk.
What We Check for Replit + Supabase
Credential Exposure
Verify no Supabase credentials are in source code (should be in Secrets).
RLS Verification
Test all tables for proper Row Level Security configuration.
Public Access
Check what's accessible without authentication.
Secrets Configuration
Verify Replit Secrets are properly configured and used.
Quick Security Wins
Apply these fixes right now to improve your security.
Move ALL Supabase credentials to Replit SecretsMake your Repl private if it contains any credentialsEnable RLS on all Supabase tablesUse separate Supabase projects for dev and productionSearch codebase for 'supabase' to find hardcoded valuesThe Bottom Line
Replit + Supabase works well when you use Replit Secrets properly and configure RLS. Never put credentials in code - free Repls are public!
Secure Your Replit + Supabase App
Find Row Level Security misconfigurations, exposed credentials, and other vulnerabilities before attackers do.
Start Security ScanFrequently Asked Questions
Are free Replit projects public by default?
Yes, free Repls are public - anyone can view your source code. This means any Supabase credentials hardcoded in your files are exposed. Always use Replit's Secrets feature for credentials, or upgrade to a paid plan for private Repls.
How do I use Replit Secrets for Supabase credentials?
In Replit, click the lock icon (Secrets) in the sidebar. Add SUPABASE_URL and SUPABASE_ANON_KEY as secrets. In your code, access them via process.env.SUPABASE_URL. Secrets are encrypted and never visible in your code, even in public Repls.
Should I use different Supabase projects for development and production?
Yes, absolutely. Create separate Supabase projects for dev and production. This prevents accidental data exposure during development and lets you test RLS policies without affecting real users. Use different Replit Secrets for each environment.
What if I accidentally committed Supabase credentials to a public Repl?
Immediately: 1) Rotate your Supabase API keys in the dashboard, 2) Remove the credentials from your code and add them to Secrets, 3) Check Supabase logs for unauthorized access. The old keys remain in Git history, so rotation is mandatory even after removing from code.