Checkout Firewall

Checkout Firewall is a Shopify App designed to prevent card testing before it reaches the payment processor. Users can customize blocking settings and choose when to start blocking fraudulent attempts. The app converts block lists, trust lists, and shared fraud matches into checkout rules, allowing merchants to stop suspicious activities before payment is made. New installs begin in Monitor mode to log potential blocks, with options to switch to Balanced or Aggressive modes for stronger protection.