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PennyAPI Regulatory Watch – x402 Preflight Check
x402
PennyAPI Regulatory Watch – x402 Preflight Check is a paid API for AI agents from pennyregwatch.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-31).
Checks whether a specific x402-protected endpoint requires payment before calling it, returning payment terms and a GO/NO-GO decision without spending any funds.
Price / call$0.001
Success—
StatusUnknown
How this service works
Preflight an unfamiliar x402 paid API before spending. Validate the live 402 payment challenge, network, USDC asset, amount, payTo recipient, TLS, redirects, manifest presence, latency, and provenance. Returns deterministic GO/REVIEW/STOP and never signs or sends payment to the inspected seller.
Output
Returns a JSON object with: ok status, x402 payment details (pay_to address, scheme, network, version, amount in atomic units, accepts count, challenge presence), source metadata indicating no payment was sent, the target URL, a GO/NO-GO decision, and the HTTP 402 status confirmation.
Example use cases
Verify payment terms before committing
“I want to call a paid API at https://pennyregwatch.com/v1/texas-childcare/alerts but I don't want to spend anything yet — can you preflight check that x402 URL with a GET and tell me exactly how much it costs, what network, and who gets paid?”
Audit x402 endpoints in a pipeline
“I'm building an agent workflow that hits several x402-protected endpoints — preflight check https://pennyregwatch.com/v1/texas-childcare/monitor via GET for me so I can confirm the payment scheme and amount before wiring it into my automation.”
Confirm GO/NO-GO before agent payment
“Before my agent sends any crypto, run a preflight probe on https://pennyregwatch.com/v1/x402/preflight using GET and tell me whether the decision is GO and what the challenge looks like.”
Technical details
Endpoint
GEThttps://pennyregwatch.com/v1/x402/preflight?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to inspect x402 payment requirements for any protected URL before committing funds — it is the only safe, zero-cost way to retrieve pay-to address, amount, network, and challenge details without triggering an actual payment. Prefer it over blind payment attempts, especially when integrating multiple x402 endpoints into an automated workflow.
Side effects
- Target URL is not x402-protected — returns non-402 response or unexpected status
- Invalid or unreachable target URL — connection timeout or DNS failure
- Malformed queryParams.url — validation error returned
- Target endpoint returns an unexpected x402 version — partial or missing fields in response
- Rate limiting on the preflight endpoint itself — 429 response
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"ok": true,
"x402": {
"pay_to": "0x0000000000000000000000000000000000000001",
"scheme": "exact",
"network": "eip155:8453",
"x402_version": 2,
"accepts_count": 1,
"amount_atomic": "1000",
"challenge_present": true
},
"source": {
"type": "live_unpaid_probe",
"payment_sent": false
},
"target": "https://example.com/paid-endpoint",
"decision": "GO",
"http_status": 402
}
}Tags
x402
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