Supabase RLS Deep Dive — Multi-tenant Access Control

Supabase Row Level Security (RLS) lets you enforce access rules at the database layer using SQL policies. Done right, your app code never needs explicit permission checks. Here are the patterns I use in a multi-tenant SaaS.

The Basics

-- Enable RLS on a table ALTER TABLE tasks ENABLE ROW LEVEL SECURITY ;

-- Only the owner can see their own rows CREATE POLICY "own_tasks_select" ON tasks FOR SELECT USING ( user_id = auth . uid ());

-- INSERT must set user_id to the caller CREATE POLICY "own_tasks_insert" ON tasks FOR INSERT WITH CHECK ( user_id = auth . uid ());

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Multi-tenant: Organization-based Access

CREATE TABLE organizations ( id UUID PRIMARY KEY DEFAULT gen_random_uuid (), name TEXT NOT NULL , slug TEXT UNIQUE NOT NULL );

CREATE TABLE organization_members ( org_id UUID REFERENCES organizations ( id ) ON DELETE CASCADE , user_id UUID REFERENCES auth .…