supabase-sdk-patterns

# Supabase SDK Patterns ## Overview Production patterns for `@supabase/supabase-js` v2 and `supabase-py`. Every Supabase query returns `{ data, error }` — never assume success. This skill covers client initialization, CRUD with filters, auth, realtime subscriptions, storage, RPC, and the Python equivalent for each pattern. ## Prerequisites - Supabase project with URL and anon key (or service role key for server-side) - `@supabase/supabase-js` v2 installed (TypeScript) or `supabase` pip package (Python) - TypeScript projects: generated database types via `supabase gen types typescript` ## Instructions ### Step 1: Initialize a Typed Singleton Client Create one client instance and reuse it. Never call `createClient` per-request. ```typescript // lib/supabase.ts import { createClient } from '@supabase/supabase-js' import type { Database } from './database.types' let supabase: ReturnType<typeof createClient<Database>> export function getSupabase() { if (!supabase) { supabase = createClient<Database>( process.env.SUPABASE_URL!, process.env.SUPABASE_ANON_KEY!, { auth: { autoRefreshToken: true, persistSession: true }, db: { schema: 'public' }, global: { headers: { 'x-app-name': 'my-app' } }, } ) } return supabase } ``` **Python equivalent:** ```python from supabase import create_client, Client _client: Client | None = None def get_supabase() -> Client: global _client if _client is None: _clien...