Pay for APIs
Learn the request → 402 → payment → retry cycle
Make a successful payment-gated API call using @x402/fetch
Understand and handle errors (insufficient funds, failures, timeouts)
Build a complete client app with best practices
Register multiple payment schemes and handle different blockchains
Add logging, metrics, and custom validation with payment hooks
Troubleshoot common errors and inspect payment flows
Implement resilient clients with exponential backoff and circuit breakers