# Counterparty / KYB / Vendor & Payee Vetting

> Counterparty / KYB / Vendor & Payee Vetting is a paid API for AI agents from x402-agent-api.onrender.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-13).

Screens a company or person against OFAC sanctions, checks company identity, domain age, email infrastructure, and on-chain wallet risk in a single call, returning a block/review/clear verdict with reasons.

## Facts

- Endpoint: POST https://x402-agent-api.onrender.com/api/v1/counterparty-check?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/counterparty-kyb-vendor-payee-vetting-618f385f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JdRL4HCOMPqed35DtTx38

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 counterparty-kyb-vendor-payee-vetting-618f385f -d '<json body>'
```

Example prompt: Before I pay Acme Robotics Inc. at wallet 0xAbC1234567890AbC1234567890AbC1234567890Ab on Base from their domain acme.com, run a full counterparty check — OFAC screen, company lookup, domain age, email validity, and on-chain wallet risk — and tell me if I should block, review, or clear them.

## When to prefer this

Choose this endpoint when you need a single-call, all-in-one counterparty due diligence check that combines OFAC sanctions screening, company KYB, domain/email infrastructure validation, and on-chain wallet risk — especially before making an automated crypto payment or onboarding a new vendor. Prefer this over point-solution tools when you need a combined block/review/clear verdict with consolidated reasoning rather than assembling separate API results yourself.

## Known failure modes

- Invalid wallet address format (must match 0x + 40 hex chars) returns validation error
- Name too short (under 2 chars) or too long (over 200 chars) rejected
- Domain not resolvable or unreachable may return partial results with missing domain/email checks
- Unknown or unsupported chain value returns enum validation error
- OFAC or third-party data source downtime may cause incomplete screening results
- Payment failure (insufficient USDC balance) returns 402 before processing

## How this service works

Counterparty / KYB / vendor and payee vetting in one call: OFAC sanctions screen of a name and crypto wallet, company identity (industry, HQ, size), domain age, email (MX, DMARC) and website checks, and an on-chain wallet risk check (Base, Ethereum). Returns block / review / clear with the reasons. Use before paying or onboarding someone. $0.02 USDC per call.

## Output

Returns a verdict of block, review, or clear along with the specific reasons: OFAC sanctions match status for the name, company identity details (industry, headquarters, size), domain registration age, email MX and DMARC record validity, website reachability, and an on-chain wallet risk assessment for the provided EVM address on Base or Ethereum.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "via": {
   "type": "string",
   "maxLength": 64,
   "description": "Optional: the tool whose next_calls suggested this call (filled in for you)."
  },
  "name": {
   "type": "string",
   "maxLength": 200,
   "minLength": 2,
   "description": "The company or person, e.g. \"Acme Robotics Inc.\" Screened against OFAC and looked up as a company."
  },
  "chain": {
   "enum": [
    "base",
    "ethereum"
   ],
   "type": "string",
   "default": "base",
   "description": "Chain of `wallet`: \"base\" (default) or \"ethereum\"."
  },
  "domain": {
   "type": "string",
   "maxLength": 300,
   "minLength": 3,
   "description": "Their website or email domain, e.g. \"acme.com\" (a URL or an email address is accepted)."
  },
  "wallet": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{40}$",
   "description": "The EVM address you would pay or receive from, e.g. an x402 payTo."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/counterparty-kyb-vendor-payee-vetting-618f385f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-agent-api.onrender.com](https://www.zero.xyz/host/x402-agent-api.onrender.com/llms.txt)