Managing Supabase

When to use this skill

• When the user asks to set up or configure a Supabase project.
• When the user needs help with Supabase Auth, Database, Storage, or Realtime.
• When the user asks about Egress issues, high costs, or performance troubleshooting.
• When the user wants to use Edge Functions or Postgres Modules (Vectors, Cron, etc.).

Workflow

1. Project Setup:
   • Connect to the project using SUPABASE_URL and SUPABASE_ANON_KEY.
   • Install the client library (e.g., @supabase/supabase-js).
2. Feature Implementation:
   • Auth: Configure providers in the dashboard, implement sign-in/sign-up logic.
   • Database: Design schemas, set up RLS (Row Level Security) policies.
   • Storage: Create buckets, set RLS, upload/download files.
3. Optimization & Troubleshooting:
   • Monitor usage (Egress, CPU, RAM) in the dashboard.
   • Analyze logs for slow queries or high-traffic paths.
   • Implement caching and optimization strategies.

Instructions

Core Features

• Database: Full Postgres. Use supabase.from('table').select('*') for basic queries. Always use RLS for security.
• Auth: Built-in support for Email/Password, Magic Links, OAuth (Google, GitHub, etc.), and SSO.
• Storage: S3-compatible object storage. Secure files with policies.
• Edge Functions: TypeScript functions (Deno-based) running closer to the user.
• Realtime: Subscribe to database changes (INSERT, UPDATE, DELETE) or broadcast events.

💰 Egress Optimization (Cost Reduction)

Egress (bandwidth) is often the highest cost driver. Follow these rules to minimize it:

1. Select Specific Fields: NEVER use select('*') in production unless absolutely necessary.
   • Bad: const { data } = await supabase.from('users').select('*')
   • Good: const { data } = await supabase.from('users').select('id, username')
2. Use Caching:
   • Use libraries like supabase-cache-helpers to cache SWR/React Query responses.
   • Enable Smart CDN for Storage to serve assets from the edge (cheaper cached egress).
3. Optimize Mutations:
   • By default, insert and update may return the modified row. If you don't need it, don't ask for it.
4. Image Optimization:
   • Use Supabase Image Transformations to resize and compress images before serving them.
   • Serving a 5MB image when a 50kb thumbnail works is a major egress leak.
5. Log Analysis:
   • Go to Log Explorer -> Top Paths to see what API routes are consuming bandwidth.
   • Use Query Performance Advisors to identify queries returning large numbers of rows.
   • Note: Supavisor (Connection Pooler) egress acts independently. If you pull 1MB to an Edge Function but return 100KB to the user, you pay for both legs.

Resources

• Supabase Documentation
• Egress Troubleshooting Guide