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AISkills402: x402 Offer Check
x402
AISkills402: x402 Offer Check is a paid API for AI agents from api.aiskills402.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-17).
Probes a public x402 payment-gated URL from the Cloudflare edge and reports what a buyer sees — payment headers, CORS behavior, 404s, and other findings by severity.
Price / call$0.01
Success—
StatusUnknown
How this service works
x402 Offer Check API: probes a public x402 storefront from the Cloudflare edge (GET, POST, OPTIONS) and reports what a buyer sees - payment-required header vs body, extra, bazaar, CORS, header size, 404 on the other method - as findings by severity. $0.01 USDC per check, a live measurement (a replayed payment header returns the receipt, not a new measurement). POST JSON {url, method?}; free example at https://api.aiskills402.com/v1/run/x402-offer-check/example
Output
A JSON object including: whether the URL is reachable, the full parsed x402 offer (asset, network, amount, pay-to address, scheme, service name), HTTP status codes for GET/POST/OPTIONS probes, response and header sizes in bytes, CORS findings, a list of findings categorized by severity, whether the endpoint is payable by a v2 client, the final URL after redirects, and a timestamp of when the check was performed.
Example use cases
Debug x402 endpoint misconfiguration
“My x402 storefront at https://api.myservice.com/v1/premium-data is returning a 404 on GET but I expected a 402 — can you probe it and tell me what's wrong and what a buyer would actually see?”
Verify new x402 listing before publishing
“I just set up an x402 payment wall at https://api.example.com/v1/report — can you check if the payment-required headers are correct, whether CORS is set up properly, and if a v2 client could pay it?”
Audit competitor x402 storefront offer
“Can you inspect what https://api.someservice.com/v1/data-feed advertises as its x402 offer — the asset, network, amount, pay-to address, and any issues — so I can compare it to my own setup?”
Technical details
Endpoint
POSThttps://api.aiskills402.com/v1/run/x402-offer-check?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to validate or debug an x402 payment-gated API from the perspective of a real buyer hitting it from the Cloudflare edge. It is especially useful for verifying offer metadata correctness, diagnosing CORS misconfigurations, checking method-specific behavior (GET vs POST), and confirming v2 client compatibility — all in one structured report with severity-ranked findings. Prefer it over manual curl-based checks when you need a machine-readable, edge-sourced audit of an x402 endpoint.
Side effects
- URL is an IP address or *.workers.dev — rejected by policy
- URL is not reachable from Cloudflare edge — reachable:false returned
- x402 endpoint returns no payment-required header — reported as a finding
- Replayed payment header returns cached receipt instead of fresh measurement
- URL resolves to a non-HTTPS scheme — rejected
- Response header size exceeds limits — flagged as a finding
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| url | string | Public https address of the x402 resource to check (port 443, a DNS name; no IP addresses, no *.workers.dev). |
| method | string | Which method to probe first; the other one is always probed too. |
Output
Schema · Response
{
"type": "json",
"example": {
"ok": true,
"skill": "x402-offer-check",
"engine": "1.0.0",
"replay": false,
"result": {
"url": "https://api.aiskills402.com/v1/run/jsonl-repair",
"offer": {
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"bazaar": "full",
"pay_to": "0x8e37022edcf0f21cf3c9f93fee9d4d32519f36f4",
"scheme": "exact",
"network": "eip155:8453",
"amount_usd": "0.003",
"amount_micro": "3000",
"resource_url": "https://api.aiskills402.com/v1/run/jsonl-repair",
"service_name": "AISkills402 API: JSONL Repair",
"x402_version": 2,
"max_timeout_seconds": 60
},
"sizes": {
"body_bytes": 2351,
"payment_required_chars": 3136,
"response_headers_bytes": 3873
},
"findings": [],
"final_url": "https://api.aiskills402.com/v1/run/jsonl-repair",
"reachable": true,
"checked_at": "2026-10-16T17:05:07.800Z",
"paid_method": "POST",
"measured_from": "recorded",
"status_by_probe": {
"GET": 405,
"POST": 402,
"OPTIONS": 204
},
"payable_by_v2_client": true
},
"receipt": {
"tx": "0x<settlement transaction>",
"settled": true
},
"refusal": null,
"input_sha256": "<sha256 of the request>"
}
}Tags
x402
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