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Foundry x402 Seller Due Diligence
x402
Foundry x402 Seller Due Diligence is a paid API for AI agents from minty-sprout.onrender.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-11-01).
Performs comprehensive pre-payment due diligence on an x402 paid endpoint, combining preflight checks, on-chain USDC payment history, and Bazaar listing verification to detect dead, fake, or mispriced sellers.
Price / call$0.01
Success—
StatusUnknown
How this service works
x402 seller due diligence: everything in x402-preflight PLUS on-chain proof of real demand (USDC actually received by the seller's payTo in the last 24h: payments, distinct payers, volume) and a Bazaar listing-truth audit (is this URL listed, does the listed price match what it charges). Reveals dead, fake or mispriced sellers before payment.
Output
Returns a JSON object with a top-level verdict (ok or issues found), the endpoint's x402 method and version, a list of any detected issues, payment options with per-option verdicts and prices, on-chain stats for the seller's payTo address (payment count, distinct payers, USDC volume over 24h, whether the address is a contract), and a Bazaar listing audit (whether the URL is listed, the listed price, and whether it matches what the endpoint actually charges).
Example use cases
Fraud check before paying unknown API
“I found this x402 endpoint at https://some-new-api.example.com/data that charges $0.01 per call — can you do a full due diligence check on it before I start paying? I want to know if it's legitimate, has real users, and whether the price matches what's listed in Bazaar.”
Verifying seller activity for marketplace integration
“I'm building a tool that aggregates x402 APIs — before I include https://weather-paid.workers.dev/forecast in my catalog, can you check how many distinct payers have used it in the last 24 hours and whether its Bazaar listing price is accurate?”
Detecting dead or abandoned paid endpoint
“This x402 endpoint https://old-seller.onrender.com/api/report used to work but I'm not sure if it's still active — can you investigate it and tell me if there's been any real USDC received recently and if there are any issues with its configuration?”
Technical details
Endpoint
POSThttps://minty-sprout.onrender.com/v1/x402-due-diligence?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need the most thorough pre-payment check on an x402 seller, going beyond basic preflight (connectivity, scheme, pricing) to include on-chain proof that real USDC has actually flowed to the seller's address and a Bazaar marketplace listing audit. Prefer it over x402-preflight alone when dealing with unfamiliar sellers, high-value automation, or when building a catalog/aggregator that must filter out dead or fraudulent endpoints.
Side effects
- URL is unreachable or not an x402 endpoint — returns issues in the issues array
- On-chain data unavailable if Base RPC is degraded — may return incomplete onchain stats
- Bazaar listing not found — checked:true but this_url_listed:false
- Seller payTo address has zero payments — reveals dead or new seller
- Price mismatch detected — price_matches_listing:false in Bazaar section
- Malformed input URL returns validation error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| input | string | URL of a paid x402 endpoint to investigate before paying it |
Output
Schema · Response
{
"type": "json",
"example": {
"url": "https://x402-preflight.nextill-pos.workers.dev/v1/preflight",
"issues": [],
"method": "GET",
"seller": {
"bazaar": {
"checked": true,
"this_url_listed": true,
"listed_price_usd": 0.003,
"price_matches_listing": true
},
"issues": [],
"pay_to": "0xB3cDDccEe6B150c8efFD55B961afc0Ecefe7f247",
"network": "eip155:8453",
"onchain": {
"payments": 34,
"window_hours": 24,
"usdc_received": 6.18,
"distinct_payers": 8,
"pay_to_is_contract": false
}
},
"status": 402,
"options": [
{
"issues": [],
"pay_to": "0xB3cDDccEe6B150c8efFD55B961afc0Ecefe7f247",
"scheme": "exact",
"network": "eip155:8453",
"verdict": "ok",
"price_usd": 0.003,
"asset_symbol": "USDC"
}
],
"verdict": "ok",
"latency_ms": 1001,
"x402_version": 2,
"bazaar_extension": true
}
}Tags
x402
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