# Page Change Detection

> Page Change Detection is a paid API for AI agents from 6xrkjcfa3yrzvefcpvanurzou4.srv.us, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-31).

Fetches a public URL and reports whether the page has changed since last check, including a SHA-256 content fingerprint, HTTP metadata, and diff statistics

## Facts

- Endpoint: GET https://6xrkjcfa3yrzvefcpvanurzou4.srv.us/api/page-change?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/page-change-detection-27d4f29f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jk2QL-DW5dufnkZ92kh7v

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 page-change-detection-27d4f29f
```

Example prompt: Check if https://example.com/pricing has changed since my last snapshot — I have the previous fingerprint hash 'abc123def456' and want to know if anything changed, how much, and what lines were added or removed.

## When to prefer this

Choose this endpoint when you need lightweight, recurring checks on whether a specific public URL has changed content, especially when you already have a prior fingerprint to compare against. It is ideal for monitoring landing pages, documentation, pricing pages, or news articles without storing full page snapshots. Prefer it over full-page scrapers when you only need change detection signals (diff percentage, added/removed lines) rather than structured extraction of the new content.

## Known failure modes

- URL is not publicly accessible or returns a non-200 HTTP status — reports the error status
- URL is paywalled or bot-protected — may return incomplete or blocked content fingerprint
- Malformed or invalid URL input — returns a validation error
- Network timeout fetching the target URL — returns a timeout error
- Prior hash format is invalid — may return a comparison error or treat as first fetch

## How this service works

Page change detection - website change monitoring, detect webpage changes, url change detection. Fetches a public URL and reports whether the page changed: the sha256 fingerprint of the text a reader sees, the HTTP status, ETag, Last-Modified and content type, and -- when you send the previous fingerprint as prior_hash -- a changed true or false verdict, the percent changed and the added and removed lines. GET ?url= OR ?prior_hash= OR ?sample=1|2|3 OR POST application/json with...

## Output

Returns a SHA-256 fingerprint of the visible text content, the HTTP status code, ETag, Last-Modified header, and content type. When a prior_hash is provided, also returns a boolean 'changed' verdict, the percentage of content that changed, and the specific lines added and removed.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object"
    }
   },
   "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/page-change-detection-27d4f29f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 6xrkjcfa3yrzvefcpvanurzou4.srv.us](https://www.zero.xyz/host/6xrkjcfa3yrzvefcpvanurzou4.srv.us/llms.txt)