# SiteSignal Vendor Due Diligence

> SiteSignal Vendor Due Diligence is a paid API for AI agents from phases-prot-shine-royal.trycloudflare.com, paid per call via x402, $0.08/call, status down (last checked 2026-09-16).

Assembles a public-website, HTTP, TLS, and response-header evidence pack for human-reviewed vendor due diligence.

## Facts

- Endpoint: GET https://phases-prot-shine-royal.trycloudflare.com/x402/vendor-due-diligence
- Price: $0.08/call
- Payment: x402
- Status: down
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitesignal-vendor-due-diligence-311ee3f4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pRdiNaiuyDr0q3_9rG3gF

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 sitesignal-vendor-due-diligence-311ee3f4
```

Example prompt: Can you run a vendor due diligence check on https://www.acmesoftware.com? We're considering them for a data-processing contract and want to see their TLS setup, HTTP security headers, and any other public web signals that might flag risk.

## When to prefer this

Choose this endpoint when you need a quick, bounded, human-readable evidence pack about a specific vendor's public web presence — particularly TLS posture and HTTP security headers — for procurement, compliance, or risk review workflows. It is not suited for deep internal audits, authenticated endpoint scanning, or continuous monitoring; prefer it for point-in-time, pre-contract due diligence snapshots.

## Known failure modes

- Vendor URL is unreachable or returns a non-200 status, resulting in incomplete evidence
- TLS handshake failure if the vendor's certificate is invalid or expired
- Missing or empty response headers if the server returns minimal headers
- Decision context or URL not provided, causing request validation failure
- Cloudflare tunnel instability leading to intermittent 5xx errors from the host

## How this service works

Create a bounded public-website, HTTP, TLS, and response-header evidence pack for human vendor due diligence.

## Output

A structured evidence pack covering public website signals, HTTP response headers, TLS configuration details, and response metadata — formatted to support human reviewers making vendor approval or rejection decisions.

## 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",
      "decisionContext"
     ],
     "properties": {
      "url": {
       "type": "string",
       "format": "uri"
      },
      "riskFocus": {
       "type": "string"
      },
      "decisionContext": {
       "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/sitesignal-vendor-due-diligence-311ee3f4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from phases-prot-shine-royal.trycloudflare.com](https://www.zero.xyz/host/phases-prot-shine-royal.trycloudflare.com/llms.txt)