# Foundry x402 Seller Due Diligence

> 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.

## Facts

- Endpoint: POST https://minty-sprout.onrender.com/v1/x402-due-diligence?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/foundry-x402-seller-due-diligence-c199cac5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qfjnm47tQizoLMFfX0pyG

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability foundry-x402-seller-due-diligence-c199cac5 -d '<json body>'
```

Example prompt: Before I pay that x402 endpoint at https://x402-preflight.nextill-pos.workers.dev/v1/preflight, run a full due diligence check on it — I want to see if the seller has real on-chain payment history, whether the price matches its Bazaar listing, and whether there are any issues I should know about.

## When to prefer this

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.

## Known failure modes

- 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

## 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).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "input": {
   "type": "string",
   "maxLength": 8000,
   "description": "URL of a paid x402 endpoint to investigate before paying it"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "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
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/foundry-x402-seller-due-diligence-c199cac5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from minty-sprout.onrender.com](https://www.zero.xyz/host/minty-sprout.onrender.com/llms.txt)