# Web Evidence Capture & Change Detection

> Web Evidence Capture & Change Detection is a paid API for AI agents from gvfcs-159-89-4-32.free.pinggy.net, paid per call via x402, $0.005/call, status down (last checked 2026-10-12).

Fetches a URL and returns a cryptographic content hash, HTTP metadata, page title, sampled links, and change detection data as tamper-evident evidence

## Facts

- Endpoint: POST https://gvfcs-159-89-4-32.free.pinggy.net/evidence?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: down
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/web-evidence-capture-change-detection-589436e7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3s-71uQViapCn6f6OqCf2

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 web-evidence-capture-change-detection-589436e7 -d '<json body>'
```

Example prompt: Can you capture evidence of what's currently on https://example.com/terms-of-service — I need the content hash, HTTP status, page title, and any detected changes from the last snapshot so I have a verifiable record.

## When to prefer this

Choose this endpoint when you need a lightweight, cryptographically verifiable snapshot of a webpage — especially for compliance, legal evidence, or change-detection workflows — rather than a full browser-rendered scrape. Ideal when you need the SHA-256 hash as proof of content state, HTTP metadata, and redirect tracing in a single call at minimal cost ($0.005 per call).

## Known failure modes

- Target URL is unreachable or times out — returns error with no content hash
- URL returns non-200 HTTP status (e.g. 404, 500) — httpStatus field reflects actual code, content may be empty
- Redirect loop detected — finalUrl may differ or request fails
- Invalid or malformed URL input — returns validation error
- Tunnel host (pinggy.io) may be intermittently unavailable — service disruption possible

## How this service works

Website hosted for free through pinggy.io&gt;
    &lt;meta name=

## Output

Returns the original URL, final URL after redirects, HTTP status code, page title, content size in bytes, SHA-256 hash of the page content, a sample of links found on the page, change detection metadata comparing to prior snapshots, and a payment receipt.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "url"
 ],
 "properties": {
  "url": {
   "type": "string",
   "description": "http(s) URL to capture evidence for"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "url",
  "contentSha256"
 ],
 "properties": {
  "url": {
   "type": "string"
  },
  "bytes": {
   "type": "integer"
  },
  "title": {
   "type": "string"
  },
  "receipt": {
   "type": "object"
  },
  "finalUrl": {
   "type": "string"
  },
  "httpStatus": {
   "type": "integer"
  },
  "linksSample": {
   "type": "array",
   "items": {
    "type": "string"
   }
  },
  "contentSha256": {
   "type": "string"
  },
  "changeDetection": {
   "type": "object"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/web-evidence-capture-change-detection-589436e7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gvfcs-159-89-4-32.free.pinggy.net](https://www.zero.xyz/host/gvfcs-159-89-4-32.free.pinggy.net/llms.txt)