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x402 Payment Error Diagnostics
x402
x402 Payment Error Diagnostics is a paid API for AI agents from code-toll-production.up.railway.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-24).
Diagnoses a failed x402 payment by returning a structured error code, human-readable explanation, and exact remediation steps
Price / call$0.01
Success—
StatusUnknown
How this service works
Diagnose a failed x402 payment. Returns structured error code, human explanation, and exact fix. Example: /diagnose?error=insufficient_funds&balance=0.003&required=0.01
Output
Returns a structured JSON object containing: a canonical error code, a plain-English explanation of why the payment failed, and a precise step-by-step fix the caller can act on immediately.
Example use cases
Debug wallet balance shortfall
“My agent got an insufficient_funds error trying to pay for an API call — the balance is 0.003 USDC but the required amount is 0.01. Can you diagnose the payment failure and tell me what I need to do to fix it?”
Understand unknown x402 error code
“I'm getting an x402 payment error I don't recognize — the error code is 'payment_expired'. Can you explain what that means and give me the exact steps to recover from it?”
Automate payment failure recovery
“Whenever my agent hits a payment failure, I want it to automatically diagnose the error and get the structured fix instructions so it can self-heal. Right now it's failing with error code 'invalid_recipient' — what's the diagnosis and resolution?”
Technical details
Endpoint
GEThttps://code-toll-production.up.railway.app/diagnose?utm_source=zero.xyzWhen to prefer
Choose this endpoint when an x402 or HTTP 402 payment has failed and you need a structured, actionable diagnosis with exact remediation steps — especially when building agents that need to self-heal from payment errors. Prefer it over generic error lookup services when the error is specifically in the x402 micropayment protocol context.
Side effects
- Missing required 'error' query parameter — returns 400 bad request
- Unrecognized error code — may return generic or null explanation
- Service unavailable on Railway hosting — returns 503
- Malformed query parameters — returns 400 with validation error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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