# Horizon Pulse x402 Deep Check

> Horizon Pulse x402 Deep Check is a paid API for AI agents from horizonpulse.dev, paid per call via x402, $0.03/call, status unknown (last checked 2026-10-30).

Performs a comprehensive security and compliance audit of an x402 payment endpoint, including TLS, security headers, CORS, payTo address verification, lookalike detection, and discovery drift analysis — without paying or signing.

## Facts

- Endpoint: GET https://horizonpulse.dev/api/x402-check/deep?utm_source=zero.xyz
- Price: $0.03/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-x402-deep-check-b5c7ef8e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ABkoMAxgAjT3SeefHoP_K

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-x402-deep-check-b5c7ef8e
```

Example prompt: Before my agent starts paying this API, can you do a full deep security check on https://api.example.com/generate — verify the payTo address matches their published addresses, check TLS and security headers, look for lookalike fraud, and see if the live 402 response drifts from their well-known or Bazaar listings?

## When to prefer this

Choose this endpoint when you need a comprehensive, one-call security and authenticity audit of an x402 endpoint before paying it — especially when you want to verify payTo addresses against multiple published sources, detect potential fraud or drift, and assess TLS/CORS/header security. Prefer this over the basic x402-check endpoint when fraud risk, address verification, and discovery drift are important, or when integrating a new x402 API into an automated agent workflow where payment mistakes are costly.

## Known failure modes

- Bad input URL (private/localhost/blocked host) — not billed, returns error immediately
- Target URL timeout — not billed
- Target returns non-HTTP error (DNS failure, connection refused) — not billed
- Any HTTP response from target (including 4xx/5xx) — billed at $0.03
- Well-known or OpenAPI docs unreachable — partial report with missing comparison fields
- CDP Bazaar listing not found — drift check skipped for that source

## How this service works

x402 endpoint deep check, never pays or signs: the full /api/x402-check report plus live checks. GET url (optional method, body). Adds TLS, security headers, CORS, payTo vs the payee's own published addresses (/.well-known/x402, openapi.json, llms.txt), lookalike payTo detection, and drift between the live 402 and well-known, openapi and CDP Bazaar listings. Any HTTP answer from the target is billed; bad input, blocked hosts and timeouts are not.

## Output

A detailed deep-check report covering: TLS certificate validity and configuration, HTTP security headers presence/quality, CORS policy analysis, the decoded x402 payment terms (payTo address, price, accepted tokens), comparison of payTo against addresses published in /.well-known/x402, openapi.json, and llms.txt, lookalike/typosquatting detection on the payTo address, and drift analysis between the live 402 response and the endpoint's well-known, OpenAPI, and CDP Bazaar listings.

## 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"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "description": "Absolute http(s) URL of the x402 endpoint to check (required). Private/localhost blocked."
      },
      "body": {
       "type": "string",
       "description": "Optional JSON body (<=8KB, URL-encoded) sent with a POST probe. Implies POST."
      },
      "method": {
       "type": "string",
       "description": "HTTP method for the unpaid probe: GET (default; one POST retry on 405) or POST."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "description": "Horizon Pulse x402 deep check: x402-check report plus TLS, security headers, CORS, payTo vs published addresses, lookalike payTo, discovery drift. The example is a trimmed real response recorded from GET /api/demo/x402-check-deep at 2026-10-19T19:46Z UTC; live values differ on every call."
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/horizon-pulse-x402-deep-check-b5c7ef8e/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)