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x402 Doctor — URL Payability Checker
x402
x402 Doctor — URL Payability Checker is a paid API for AI agents from agentx.sale, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-21).
Validates whether a URL is a properly implemented x402 agent-payable resource, grading it against v1 and v2 of the x402 spec and returning a verdict with grade
Price / call$0.02
Success—
StatusUnknown
How this service works
x402 Doctor: is a URL a valid agent-payable paid resource? v1+v2 spec check with grade and verdict
Output
Returns a compliance verdict and grade indicating whether the target URL correctly implements the x402 paid resource protocol, with specific feedback against v1 and/or v2 spec requirements, highlighting any failures or gaps in the implementation.
Example use cases
Pre-integration x402 compliance audit
“Before I wire up payments to https://api.myservice.com/premium-data, can you check if it's actually a valid x402 resource — does it pass the spec, and what grade does it get?”
Debugging a broken x402 endpoint
“My x402-protected endpoint at https://agentx.sale/some-resource seems to be rejecting agents even when they pay — can you run the x402 doctor on it and tell me what's wrong with the spec compliance?”
Vetting a third-party paid API before use
“I'm about to build an agent that calls https://thirdparty.io/data-feed, which claims to support x402 payments — can you validate whether it actually implements the spec correctly and give me a grade?”
Technical details
Endpoint
GEThttps://agentx.sale/x402/x402-check?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to verify that a specific URL correctly implements the x402 payment protocol before integrating it into an agentic workflow, or when debugging why an x402-protected resource is not behaving as expected. Prefer this over manual spec review when you need a quick, graded, machine-readable compliance verdict covering both v1 and v2 of the x402 spec.
Side effects
- Target URL is unreachable or returns a non-402 status when probed — validation cannot proceed
- URL is not an HTTP GET endpoint — method mismatch with x402 check requirements
- Target URL has no x402 payment headers at all — returns not-a-paid-resource verdict
- Network timeout reaching the target URL
- Malformed URL input causes schema validation error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"url": "https://example.com/paid",
"grade": "A",
"verdict": "agent-payable"
}
}Tags
x402
Reviews
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