Supabase Security Basics

Overview

Security best practices for Supabase API keys, tokens, and access control.

Prerequisites

• Supabase SDK installed
• Understanding of environment variables
• Access to Supabase dashboard

Instructions

Step 1: Configure Environment Variables

# .env (NEVER commit to git)
SUPABASE_API_KEY=sk_live_***
SUPABASE_SECRET=***

# .gitignore
.env
.env.local
.env.*.local

Step 2: Implement Secret Rotation

# 1. Generate new key in Supabase dashboard
# 2. Update environment variable
export SUPABASE_API_KEY="new_key_here"

# 3. Verify new key works
curl -H "Authorization: Bearer ${SUPABASE_API_KEY}" \
  https://api.supabase.com/health

# 4. Revoke old key in dashboard

Step 3: Apply Least Privilege

Environment	Recommended Scopes
Development	read, write
Staging	read, write, admin
Production	read, write

Output

• Secure API key storage
• Environment-specific access controls
• Audit logging enabled

Error Handling

Security Issue	Detection	Mitigation
Exposed API key	Git scanning	Rotate immediately
Excessive scopes	Audit logs	Reduce permissions
Missing rotation	Key age check	Schedule rotation

Examples

Service Account Pattern

const clients = {
  reader: new SupabaseClient({
    apiKey: process.env.SUPABASE_READ_KEY,
  }),
  writer: new SupabaseClient({
    apiKey: process.env.SUPABASE_WRITE_KEY,
  }),
};

Webhook Signature Verification

import crypto from 'crypto';

function verifyWebhookSignature(
  payload: string, signature: string, secret: string
): boolean {
  const expected = crypto.createHmac('sha256', secret).update(payload).digest('hex');
  return crypto.timingSafeEqual(Buffer.from(signature), Buffer.from(expected));
}

Security Checklist

• API keys in environment variables
• .env files in .gitignore
• Different keys for dev/staging/prod
• Minimal scopes per environment
• Webhook signatures validated
• Audit logging enabled

Audit Logging

interface AuditEntry {
  timestamp: Date;
  action: string;
  userId: string;
  resource: string;
  result: 'success' | 'failure';
  metadata?: Record<string, any>;
}

async function auditLog(entry: Omit<AuditEntry, 'timestamp'>): Promise<void> {
  const log: AuditEntry = { ...entry, timestamp: new Date() };

  // Log to Supabase analytics
  await supabaseClient.track('audit', log);

  // Also log locally for compliance
  console.log('[AUDIT]', JSON.stringify(log));
}

// Usage
await auditLog({
  action: 'supabase.api.call',
  userId: currentUser.id,
  resource: '/v1/resource',
  result: 'success',
});

Resources

• Supabase Security Guide
• Supabase API Scopes

Next Steps

For production deployment, see supabase-prod-checklist.