# Extract IDs as JSON - Change Watch

> Extract IDs as JSON - Change Watch is a paid API for AI agents from page.intel.rallylive.ca, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-20).

Monitors a web page for changes in extracted HTML element IDs, returning a diff with before/after values and a changed flag

## Facts

- Endpoint: GET https://page.intel.rallylive.ca/watch/page/ids/json?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/extract-ids-as-json-change-watch-8d0ca321
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nFZJM4lZ_At_Gfl7w5K9I

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 extract-ids-as-json-change-watch-8d0ca321
```

Example prompt: Keep an eye on https://example.com for me — every time you check it, tell me whether the HTML element IDs on the page have changed since the last check, and show me exactly what was added or removed.

## When to prefer this

Choose this endpoint when you need to detect structural changes to a web page over time by tracking its HTML element IDs, and you want a built-in diff mechanism without maintaining your own snapshot storage. It is ideal for scheduled monitoring workflows where you poll periodically and need a clear changed/unchanged signal with field-level before/after details. Prefer it over generic scraping endpoints when change detection and alerting — not just one-time extraction — is the goal.

## Known failure modes

- Target URL is unreachable or returns non-200 status — check will fail or return empty results
- First-time call has no prior snapshot to compare against — 'changed' will be null or false by default
- Snapshot older than 90 days has expired — comparison baseline is lost
- Page uses dynamic JavaScript rendering — IDs may not be fully captured via static fetch
- Rate limiting or blocking by target site — incomplete extraction

## How this service works

Change watch for extract ids as json: runs the check, compares it with the result from your previous call for the same url (kept 90 days) and returns the current answer, changed true/false, the fields that changed with before/after values, and when it was last seen. Schedule it to be alerted when this changes. $0.02 per check.

## Output

Returns a JSON object containing the current list of extracted IDs from the page, a boolean 'changed' field indicating whether the result differs from the previous call for that URL (stored up to 90 days), the specific fields that changed with their before and after values, and a timestamp of when the page was last seen.

## 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/extract-ids-as-json-change-watch-8d0ca321/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from page.intel.rallylive.ca](https://www.zero.xyz/host/page.intel.rallylive.ca/llms.txt)