# SiteSignal Vendor Due Diligence

> SiteSignal Vendor Due Diligence is a paid API for AI agents from trinity-throw-thursday-gravity.trycloudflare.com, paid per call via x402, $0.08/call, status unknown (last checked 2026-09-14).

Collects a bounded evidence pack of public-website, HTTP, TLS, and response-header signals for a vendor URL to support human due diligence decisions.

## Facts

- Endpoint: GET https://trinity-throw-thursday-gravity.trycloudflare.com/x402/vendor-due-diligence
- Price: $0.08/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitesignal-vendor-due-diligence-5d5cdeac
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_c9_OdWJOZqnAMY02C2r6S

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-5d5cdeac
```

Example prompt: Can you pull a public due diligence evidence pack for https://acme-vendor.com? We're evaluating them as a payments processor, so focus on TLS certificate quality and security headers.

## When to prefer this

Choose this endpoint when you need a quick, bounded public evidence pack for vendor due diligence that covers TLS, HTTP, and security-header signals in a single call — especially when you have a specific decision context (e.g. procurement, compliance review, contract signing) and want structured, human-reviewable output. Prefer this over raw TLS or header checkers when you need a holistic, decision-focused artifact rather than a single-signal inspection.

## Known failure modes

- Invalid or unreachable URL returns an error indicating the target could not be fetched
- Private or intranet URLs not accessible from the public internet will fail
- Missing required 'url' or 'decisionContext' query parameters returns a validation error
- Cloudflare Tunnel downtime may cause intermittent 5xx errors
- Vendor sites with aggressive bot blocking may return incomplete or blocked responses

## How this service works

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

## Output

Returns a structured evidence pack including TLS certificate metadata (issuer, expiry, chain), observed HTTP response headers (HSTS, CSP, X-Frame-Options, etc.), security header grades, and other observable public signals for the target vendor URL — formatted to support human review in a due diligence process.

## 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-5d5cdeac/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from trinity-throw-thursday-gravity.trycloudflare.com](https://www.zero.xyz/host/trinity-throw-thursday-gravity.trycloudflare.com/llms.txt)