Supabase Common Errors

Overview

Diagnostic guide for Supabase errors across PostgREST (PGRST*), PostgreSQL (numeric codes), Auth, Storage, and Realtime. Identify the error layer, trace the root cause, and apply the correct fix — every SDK call returns { data, error } where data is null when error exists.

The workflow is three steps: capture the error object, classify it by layer and code, then apply and verify the fix. Full step-by-step code lives in the diagnostic walkthrough; complete lookup tables are in the error reference.

Prerequisites

• @supabase/supabase-js installed (npm install @supabase/supabase-js)
• SUPABASE_URL and SUPABASE_ANON_KEY (or SUPABASE_SERVICE_ROLE_KEY) configured
• Access to Supabase Dashboard (for log inspection and SQL Editor)
• Supabase CLI installed for local development (npx supabase --version)

Instructions

Step 1 — Capture the Error Object

Every Supabase SDK call returns a { data, error } tuple. Never assume data exists — always destructure and check error first, because data is null whenever error is set.