# SiteSignal URL & Webpage Evidence

> SiteSignal URL & Webpage Evidence is a paid API for AI agents from trinity-throw-thursday-gravity.trycloudflare.com, paid per call via x402, $0.02/call, status down (last checked 2026-09-16).

Fetches a reproducible snapshot of a public webpage's HTTP status, redirect chain, content hash, and optional text-presence evidence for verification and monitoring.

## Facts

- Endpoint: GET https://trinity-throw-thursday-gravity.trycloudflare.com/x402/url-evidence
- Price: $0.02/call
- Payment: x402
- Status: down
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitesignal-url-webpage-evidence-84e62718
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Zo2MMlIiT_eWaBK0QLvBT

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-url-webpage-evidence-84e62718
```

Example prompt: Check whether https://example.com/terms is live, capture its content hash, and confirm the text 'last updated 2024' appears on the page (case-insensitive).

## When to prefer this

Choose this endpoint when you need a verifiable, reproducible point-in-time snapshot of a public webpage's availability, redirect behavior, and content — especially when you want cryptographic content hashing or text-presence evidence for compliance, monitoring, or research. Prefer it over generic HTTP checkers when you need structured, agent-consumable output with optional text matching and a consistent schema suitable for audit trails.

## Known failure modes

- URL is unreachable or times out — returns an error with no snapshot data
- URL is malformed or not a valid URI — validation error before request is made
- Expected text not found — returns the snapshot but with a negative text-presence result
- Target page returns a non-200 status (e.g. 404, 503) — status is reported but content may be absent
- Redirect loop detected — may return an error or truncated chain
- Rate limiting or blocking by the target server — snapshot may fail with connection error

## How this service works

Verify a public webpage with a bounded, reproducible snapshot of website status, redirects, content hash, and optional text-presence evidence for monitoring and research.

## Output

Returns a bounded snapshot including the final HTTP status code, redirect chain (if any), a content hash of the response body, whether the optional expected text was found on the page, and response metadata — all reproducible and timestamped for audit or monitoring purposes.

## 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",
       "format": "uri"
      },
      "expectedText": {
       "type": "string",
       "maxLength": 500
      },
      "caseSensitive": {
       "type": "boolean",
       "default": false
      }
     }
    }
   },
   "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-url-webpage-evidence-84e62718/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)