Supabase
Security Guide

How to Secure Your Supabase App

Supabase is secure by design, but requires proper configuration. This guide covers the essential security steps for any Supabase-powered application.

Step-by-Step Security Guide

1. Enable RLS on All Tables

Row Level Security is the foundation of Supabase security. Enable it on every table that contains data.

ALTER TABLE profiles ENABLE ROW LEVEL SECURITY;
ALTER TABLE posts ENABLE ROW LEVEL SECURITY;

2. Write Restrictive Policies

Use the (select auth.uid()) pattern for better performance. Test policies with different user contexts.

CREATE POLICY "Users read own profile" ON profiles
  FOR SELECT TO authenticated
  USING ((select auth.uid()) = id);

3. Protect Service Role Key

The service_role key bypasses RLS. Never expose it in frontend code. Use it only in server-side functions.

4. Secure RPC Functions

Database functions should check authentication. Use SECURITY DEFINER carefully.

CREATE FUNCTION get_user_data()
RETURNS json AS $$
BEGIN
  IF auth.uid() IS NULL THEN
    RAISE EXCEPTION 'Not authenticated';
  END IF;
  -- function logic
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;

5. Configure Auth Settings

Enable email confirmation, set password requirements, and configure rate limiting in the Supabase dashboard.

6. Test Your Policies

Query your database as an anonymous user to verify RLS is working. VAS does this automatically.

Common Security Mistakes

Avoid these common Supabase security pitfalls:

Creating tables without enabling RLS
Using auth.uid() instead of (select auth.uid())
Exposing service_role key in client code
Creating overly permissive policies
Not testing RLS with real queries

Recommended Security Tools

Use these tools to maintain security throughout development:

VAS Security Scanner
npm audit / yarn audit
Git-secrets
Snyk

Ready to Secure Your App?

Security is an ongoing process, not a one-time checklist. After implementing these steps, use VAS to verify your Supabase app is secure before launch, and consider regular scans as you add new features.