# x402 Counterparty Trust Check

> x402 Counterparty Trust Check is a paid API for AI agents from agentdata-api.sander-van-aard.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-13).

Aggregates Bazaar catalog presence, on-chain USDC payment history on Base, and EU regulatory status to provide factual due-diligence data on an x402 service counterparty before payment

## Facts

- Endpoint: POST https://agentdata-api.sander-van-aard.workers.dev/x402/counterparty-check
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-counterparty-trust-check-603cba46
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_L_PrWkA0Bv92IAHr_BxMt

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 x402-counterparty-trust-check-603cba46 -d '<json body>'
```

Example prompt: Before I pay this x402 API, can you run a counterparty check on the pay_to address 0xAbC123... and the service URL api.example.com — I want to see its Bazaar catalog stats, recent USDC payment history on Base, and whether the domain is MiCA-authorised or flagged by ESMA?

## When to prefer this

Use this endpoint when an AI agent is about to make an x402 micropayment to an unfamiliar service and needs factual, multi-source due diligence data. It is uniquely suited for the x402 ecosystem because it combines three heterogeneous signals (Bazaar catalog, Base on-chain history, EU regulatory status) in a single call. Prefer this over generic blockchain explorers when you need catalog and regulatory context together, and over pure regulatory checks when on-chain usage data matters.

## Known failure modes

- Address not found on-chain — returns empty payment history, not an error
- Service domain not in EU regulatory databases — returns absence data, not negative signal
- Invalid Base address format — likely 4xx validation error
- Bazaar catalog query fails — partial result returned for other sources
- Service URL unreachable for domain lookup — partial result with error on that field
- Rate limiting or upstream source timeout — 5xx error or degraded response

## How this service works

Trust check before paying an unfamiliar x402 service, by pay_to address and/or service URL. Combines our own availability monitoring of the service's x402 endpoint (30-day uptime, last check, observed payTo/price and drift between our measurements), on-chain USDC payment history to the address on Base (2-day window), and EU regulatory status of the domain (MiCA-authorised or ESMA warning list). Factual only — no scores; not being monitored is not negative, presence is no endorsement.

## Output

Returns factual aggregated data including: whether the service is listed in the Bazaar catalog with 30-day usage statistics; on-chain USDC payment history to the address on Base (number of payments, unique payers, total volume over a 3-day window); and EU regulatory status of the service domain (whether it is MiCA-authorised or appears on the ESMA warning list). No scores or recommendations are provided — raw factual signals only.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object"
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    }
   },
   "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/x402-counterparty-trust-check-603cba46/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentdata-api.sander-van-aard.workers.dev](https://www.zero.xyz/host/agentdata-api.sander-van-aard.workers.dev/llms.txt)