supabase-expert

name	supabase-expert
description	Use when building or debugging Supabase features — RLS policies, Auth flows, Storage rules, Edge Functions, and real-time subscriptions
tier	HIGH
value_tier	production
tags	["supabase","postgresql","auth","rls","database"]
entitlements	{"product_tiers":["pro","enterprise"],"agent_access":["all"]}

Supabase Expert Skill

Database Schema

RLS Policies

-- Enable RLS
ALTER TABLE profiles ENABLE ROW LEVEL SECURITY;

-- Policy: Users can read own profile
CREATE POLICY "Users can view own profile"
ON profiles FOR SELECT
USING (auth.uid() = user_id);

-- Policy: Users can update own profile
CREATE POLICY "Users can update own profile"
ON profiles FOR UPDATE
USING (auth.uid() = user_id);

Relationships

• Use foreign keys for all relationships
• Add indexes on frequently queried columns
• Consider partial indexes for permission filtering

Authentication

Secure Flow

// Sign up with email confirmation
const { data, error } = await supabase.auth.signUp({
  email: '[e-mail]',
  password: 'secure-password',
  options: {
    emailRedirectTo: 'https://yoursite.com/auth/callback'
  }
})

Session Management

// Check current session
const { data: { session } } = await supabase.auth.getSession()

// Listen for auth changes
supabase.auth.onAuthStateChange((event, session) => {
  if (event === 'SIGNED_IN') {
    // Handle sign in
  }
})

Edge Functions

Deno Runtime

import { serve } from 'https://deno.land/std@0.168.0/http/server.ts'
import { createClient } from 'https://esm.sh/@supabase/supabase-js@2'

serve(async (req) => {
  const supabase = createClient(Deno.env.get('SUPABASE_URL')!, Deno.env.get('SUPABASE_ANON_KEY')!)
  // Your logic here
})

Storage

Bucket Management

// Upload file
const { data, error } = await supabase.storage
  .from('avatars')
  .upload('folder/filename', file)

Real-time

Subscribe to Changes

const subscription = supabase
  .channel('custom-insert-channel')
  .on('postgres_changes', { 
    event: 'INSERT', 
    schema: 'public', 
    table: 'messages' 
  }, (payload) => {
    console.log('New message:', payload.new)
  })
  .subscribe()

Performance

Query Optimization

• Select only needed columns
• Use .single() for single row queries
• Implement pagination for large datasets
• Add proper indexes