Errors
Use the normal x402 decision tree: can the client pay, can it replay cleanly, and can it satisfy SIWX when the route is wallet-bound.
Most common failure cases
| Code or class | What it means | What to do next |
|---|---|---|
402 Payment Required | The route is paid and the initial request had no acceptable payment proof | Read PAYMENT-REQUIRED, build the payment payload, and replay with PAYMENT-SIGNATURE |
| Settlement rejection | The replayed payment does not satisfy the live x402 requirements | Re-read the challenge and verify network, asset, amount, recipient, and replay inputs |
| SIWX verification failure | The wallet-bound route did not accept the SIGN-IN-WITH-X proof | Check wallet, domain, URI, freshness, and signature |
| Missing execution access token | The onchain execution status read is missing X-Onchain-Execution-Access-Token | Use the token returned by onchain route resolution |
| Validation error | The request shape is invalid before pricing or fulfillment | Fix the route body or query and retry with a new logical request |