# page-change-detect-watch

> page-change-detect-watch is a paid API for AI agents from intel.rallylive.ca, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Runs a page change detection check and compares it against the previous result for the same URL (stored 90 days), returning whether the page changed, which fields changed with before/after values, and when it was last seen.

## Facts

- Endpoint: GET https://intel.rallylive.ca/watch/site/change-detect
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/page-change-detect-watch-828ecffc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7Sdi7oX8Ld_9IgZK4BVQS

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-detect-watch-828ecffc
```

Example prompt: Check if the page at https://example.com/pricing has changed since the last time you looked at it, and tell me exactly what fields are different now versus before.

## When to prefer this

Choose this endpoint when you need to know not just the current state of a page but specifically whether it has changed since a previous check, with granular field-level diffs (before/after values). It is ideal for scheduled monitoring workflows where an agent periodically polls a URL and only needs to act when something actually changes. Prefer it over simple scraping endpoints when change detection history and diffing are required without building your own storage layer.

## Known failure modes

- URL not previously seen (no comparison baseline, first call returns current state only)
- URL is unreachable or returns an error (HTTP error or timeout)
- URL blocked by robots.txt or anti-scraping measures
- 90-day retention window expired, so no prior result exists for comparison
- Invalid or malformed URL input
- Payment failure prevents the check from running

## How this service works

Change watch for page change detect: runs the check and compares it with the result from your previous call for the same url (kept 90 days), returning the current answer, changed true/false, exactly which fields changed with before/after values, and when it was last seen. Call it on a schedule to be told when page change detection changes. $0.01 per check.

## Output

Returns the current page change detection result, a boolean 'changed' flag indicating whether the page differs from the previous call for the same URL, a list of exactly which fields changed with their before and after values, and the timestamp of when the page was last seen. The previous result is retained for 90 days per URL.

## 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",
     "properties": {}
    }
   },
   "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-detect-watch-828ecffc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from intel.rallylive.ca](https://www.zero.xyz/host/intel.rallylive.ca/llms.txt)