# X402 Settlement Attestation Service

> X402 Settlement Attestation Service is a paid API for AI agents from agentdata-api.sander-van-aard.workers.dev, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-15).

Verifies an on-chain x402 payment settlement, screens the counterparty name against EU/UN sanctions lists, and returns a signed Ed25519 attestation for audit purposes

## Facts

- Endpoint: POST https://agentdata-api.sander-van-aard.workers.dev/x402/settlement-attest
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-settlement-attestation-service-0ff05d33
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AeD9rNuBFUofoQqRDoGO4

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-settlement-attestation-service-0ff05d33 -d '<json body>'
```

Example prompt: I just received an x402 payment — can you verify the settlement on-chain for transaction 0xabc123, confirm the recipient address 0xSELLER and amount of 10 USDC are correct, screen the payer company 'Acme Trading GmbH' against EU and UN sanctions lists, and give me a signed attestation I can keep as my audit record?

## When to prefer this

Use this endpoint when you are the seller/recipient of an x402 agent payment and need to (1) confirm the transaction actually settled on-chain with the correct recipient and amount, (2) simultaneously screen the paying party against EU and UN sanctions lists, and (3) obtain a cryptographically signed, offline-verifiable audit record of the event — all in a single call. Prefer this over separate blockchain explorers and standalone sanctions APIs when you need a combined, signed attestation rather than raw data.

## Known failure modes

- Transaction not yet confirmed on-chain — returns unconfirmed status rather than attestation
- Recipient address mismatch — attestation flags incorrect recipient
- Amount mismatch — flags discrepancy between expected and actual settlement amount
- Counterparty name hits on sanctions list — attestation includes positive match details
- Invalid or malformed transaction hash — returns validation error
- Network/RPC timeout when querying blockchain — service error response
- Unsupported blockchain network — returns unsupported network error

## How this service works

For a seller receiving an agent payment: verify the settlement on-chain (tx confirmed, correct recipient and amount), report the payer wallet's on-chain history, screen the provided counterparty name against the EU and UN sanctions lists, and return an Ed25519-signed attestation you keep as your audit record (verifiable offline via /.well-known/attest-keys.json). Facts and proof, never a guarantee, custody or compliance verdict. Name appears only as SHA-256.

## Output

Returns an Ed25519-signed attestation object containing: on-chain confirmation status of the transaction, verification that recipient and amount match, the payer wallet's historical on-chain activity summary, sanctions screening results against EU consolidated and UN lists (counterparty name stored only as SHA-256 hash), and a reference to the public key at /.well-known/attest-keys.json for offline signature verification. The attestation serves as an audit record but is explicitly not a compliance verdict or custody guarantee.

## 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-settlement-attestation-service-0ff05d33/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)