SUPABASE ROW LEVEL SECURITY (RLS) GUIDE | VIBEEVAL

RLS is Not Enabled by Default

AI-generated Supabase schemas rarely include RLS policies. Without explicit ALTER TABLE ENABLE ROW LEVEL SECURITY statements, all data is publicly accessible to anyone with your API key, even if you have authentication implemented.

Supabase RLS Implementation Checklist

Follow these 12 steps to properly implement Row Level Security in Supabase. Critical items must be completed for every table containing user data.

Enable RLS on all tables

Activate Row Level Security on every table containing user data. Without RLS, all data is publicly accessible regardless of authentication.

Create policies for SELECT operations

Define who can read data. Use user_id matching for user-owned records, role checks for admin access, and public flags for shared content.

Create policies for INSERT operations

Control who can create new records. Typically allow authenticated users to insert their own data, with user_id automatically set to auth.uid().

Create policies for UPDATE operations

Restrict updates to record owners or admins. Prevent users from modifying other users’ data or changing ownership fields.

Create policies for DELETE operations

Define deletion permissions. Usually limited to record owners or admins. Consider soft deletes for audit trails.

Test policies with different user roles

Verify policies work correctly by testing as authenticated user, different user, admin, and anonymous user for every table.

Protect sensitive columns

Use SECURITY DEFINER functions for operations requiring elevated privileges. Hide columns like email, phone, or payment info from unauthorized users.

Implement role-based access control

Add role checks to policies using auth.jwt() → ‘role’ for admin, moderator, or custom role permissions.

Add rate limiting to RPC functions

Prevent abuse of custom functions by implementing rate limiting or requiring authentication for all RPC calls.

Audit cross-table access patterns

Review policies that join multiple tables. Ensure RLS on related tables prevents unauthorized data access through joins.

Monitor policy performance

Complex RLS policies can slow queries. Use EXPLAIN to analyze query plans and optimize policies with indexes.

Document policy decisions

Comment your RLS policies explaining business logic. Future developers need to understand why policies exist to maintain security.

Common RLS Issues in AI-Generated Code

RLS Disabled on Tables

AI-generated schemas often omit ALTER TABLE … ENABLE ROW LEVEL SECURITY, leaving all data publicly accessible

Missing DELETE Policies

Policies for SELECT/INSERT/UPDATE exist but DELETE is forgotten, allowing unauthorized data deletion

Overly Permissive Policies

Using true as policy condition or auth.uid() IS NOT NULL without ownership checks grants access to all authenticated users

Service Role Key in Frontend

Using service_role key in client code bypasses RLS entirely, exposing all database data

Related Resources

Supabase Security Guide

Complete Supabase security best practices

Database Security Best Practices

Universal database security principles

Authentication Implementation

Implementing secure authentication

Authorization Patterns

RBAC and access control models

Test Your Supabase RLS Policies

VibeEval automatically tests your Supabase RLS policies across different user roles and scenarios to identify missing policies and overly permissive rules.