# Horizon Pulse Seller Due-Diligence for x402 Endpoints

> Horizon Pulse Seller Due-Diligence for x402 Endpoints is a paid API for AI agents from horizonpulse.dev, paid per call via x402, $5/call, status unknown (last checked 2026-10-30).

Runs a 5-check due-diligence audit on a single x402 endpoint — including a real capped test payment — and returns a signed JSON verdict of evidenced facts about the seller.

## Facts

- Endpoint: POST https://horizonpulse.dev/api/seller-dd/single?utm_source=zero.xyz
- Price: $5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/horizon-pulse-seller-due-diligence-for-x402-endpoints-03c5fe5d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JC_CqPqUcNRuFYaOQD3HC

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 horizon-pulse-seller-due-diligence-for-x402-endpoints-03c5fe5d -d '<json body>'
```

Example prompt: Before I integrate this x402 API at https://api.example.com/data, can you run a full seller due-diligence check on it — make the test payment, validate the response schema, and confirm the payTo address matches 0xAbC123...?

## When to prefer this

Use this endpoint when you need cryptographically evidenced, multi-factor due diligence on an x402 endpoint before integrating or paying it — especially when you want to screen for lookalike wallet address fraud, validate schema compliance with an actual test payment, or cross-reference the payTo with Coinbase CDP Bazaar. Prefer this over manual inspection or single-factor checks when the stakes of integrating a fraudulent or misconfigured x402 seller are meaningful.

## Known failure modes

- Test payment fails — charge not incurred, no verdict returned
- Endpoint URL is unreachable or returns non-x402 response — validation cannot proceed
- payTo address in endpoint response is missing or malformed — schema check fails
- CDP Bazaar lookup returns no listing for the seller — comparison step incomplete
- On-chain data unavailable for the payTo address — USDC history check skipped
- All 5 checks must complete for billing to occur — partial runs are not charged

## How this service works

Seller due-diligence for one x402 endpoint. We make a real capped test payment, check the paid response against the listed schema, compare payTo with the CDP listing, read a recent window of on-chain USDC payments to the payTo and screen for lookalike addresses. Returns a signed JSON verdict of evidenced facts. No charge unless the test payment and all 4 other checks complete. Facts, not endorsement; no warranty. Not affiliated with the seller checked. $5.

## Output

A signed JSON verdict containing evidenced facts from five checks: (1) result of a real capped test payment, (2) comparison of the paid response against the endpoint's declared schema, (3) comparison of the payTo address with the CDP Bazaar listing, (4) a recent window of on-chain USDC payment history to the payTo, and (5) lookalike address screening results. The verdict is cryptographically signed and states facts without warranty or endorsement.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "resource": {
   "type": "string",
   "format": "uri",
   "maxLength": 2048,
   "description": "https URL of the x402 endpoint to check (required)."
  },
  "expected_payTo": {
   "type": [
    "string",
    "null"
   ],
   "description": "Optional EVM address to compare with the endpoint's payTo."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/horizon-pulse-seller-due-diligence-for-x402-endpoints-03c5fe5d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from horizonpulse.dev](https://www.zero.xyz/host/horizonpulse.dev/llms.txt)