# Counterparty Check

> Counterparty Check is a paid API for AI agents from 402.com.tr, paid per call via x402, $0.12/call, status unknown (last checked 2026-10-11).

Validates a counterparty by checking domain age (RDAP), email deliverability (DNS), OFAC sanctions status, and LEI register existence, returning a single GO/HOLD/STOP verdict with all supporting signals.

## Facts

- Endpoint: GET https://402.com.tr/api/x402/counterparty-check?utm_source=zero.xyz
- Price: $0.12/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/counterparty-check-fc1145a6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_384CNywo0XzS3o3tBneBX

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-check-fc1145a6
```

Example prompt: Before I approve this invoice from Nexo Supplies Ltd at nexo-supplies.io, run a counterparty check on the company name 'Nexo Supplies Ltd', email billing@nexo-supplies.io, and domain nexo-supplies.io — I need to know if they're sanctioned, how old the domain is, whether email will land, and if they're in the LEI register.

## When to prefer this

Choose this endpoint when an agent needs to make a trust decision about a counterparty at the moment of invoice approval, vendor onboarding, or payment detail change — particularly when the classic fraud pattern (real-looking name, freshly registered domain) is a concern. It aggregates four distinct public data sources (RDAP, DNS, OFAC, LEI) into a single actionable verdict in one call, saving the need to chain multiple lookup APIs. Prefer it over individual WHOIS or OFAC checks when you need a combined risk signal rather than raw data.

## Known failure modes

- Domain not found in RDAP — domain age signal unavailable, verdict may degrade to HOLD
- DNS lookup failure — email deliverability signal unavailable
- OFAC API unreachable — sanctions signal missing, verdict conservatively elevated
- LEI registry timeout — company existence signal unavailable
- No input parameters provided — returns 400 bad request
- Domain is very new (weeks old) — likely STOP or HOLD verdict due to fraud risk signal

## How this service works

One call, four public sources: how old the domain is (RDAP), whether mail to the contact will land (DNS), whether the name is on the OFAC list, and whether the company exists in the global LEI register. Returns a single GO / HOLD / STOP with every signal that produced it. Built for the moment an agent has to trust an invoice, a new vendor or a payment-detail change — the classic fraud pattern is a real-looking name on a domain registered weeks ago.

## Output

Returns a single top-level verdict of GO, HOLD, or STOP along with the individual signals that produced it: domain registration age from RDAP, DNS-based email deliverability result, OFAC sanctions list match status, and LEI global company register existence check.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "pathParams": {
     "type": "object"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "name": {
       "type": "string",
       "description": "Legal company name (enables OFAC + LEI)"
      },
      "email": {
       "type": "string",
       "description": "Contact email (its domain is used if 'domain' is omitted)"
      },
      "domain": {
       "type": "string",
       "description": "Company domain"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/counterparty-check-fc1145a6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 402.com.tr](https://www.zero.xyz/host/402.com.tr/llms.txt)