# Scrooge x402 Page Watch

> Scrooge x402 Page Watch is a paid API for AI agents from scrooge-x402-tool-mill.vercel.app, paid per call via x402, $0.1/call, status unknown (last checked 2026-10-11).

Register a public URL for hourly content-change monitoring over 7 days, delivering a webhook callback when the page's content hash changes

## Facts

- Endpoint: POST https://scrooge-x402-tool-mill.vercel.app/v1/watch?utm_source=zero.xyz
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/scrooge-x402-page-watch-1ec3435f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0Gi7MgJwrP94Rif7O2kOv

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 scrooge-x402-page-watch-1ec3435f -d '<json body>'
```

Example prompt: Keep an eye on https://example.com/pricing for the next 7 days and ping my webhook at https://myapp.com/hook whenever the page content changes.

## When to prefer this

Choose this endpoint when you need passive, long-running (up to 7 days) hourly polling of a single public webpage with webhook-based push notification on change, rather than one-shot fingerprinting. Prefer it over the sibling fingerprint endpoint when you don't want to poll yourself. Best for automation pipelines that react to content changes asynchronously. Not suitable for real-time (sub-minute) monitoring or private/authenticated pages.

## Known failure modes

- 503 returned when 500 active watches are already registered — must wait for capacity
- Callback delivery fails if callback_url is unreachable within 5s timeout (one retry attempted)
- Private or link-local URLs are blocked by SSRF protection and will be rejected
- Monitor expires after 7 days with no renewal — must re-register to continue watching
- Payment of $0.10 USDC on Base (eip155:8453) must succeed before watch is created

## How this service works

Watch one public page for 7 days. Checks hourly. When the content hash changes, POST {watch_id,url,old_fingerprint,new_fingerprint,changed_at} to your https callback (5s timeout, one retry). POST JSON {"url":"https://example.com","callback_url":"https://example.com/hook"}. Returns {watch_id,url,expires,status_url}. Free status is GET /v1/watch/:id and does not show the callback. At 500 active watches, POST returns 503 before payment. $0.10 USDC on Base (eip155:8453). No API key.

## Output

Returns a JSON object with watch_id (unique monitor identifier), url (the watched page), expires (ISO timestamp 7 days out), and status_url (GET endpoint to check monitor status). When the page content hash changes within the monitoring window, a POST is sent to your callback_url containing watch_id, url, old_fingerprint, new_fingerprint, and changed_at.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "format": "uri",
   "description": "Public http(s) URL to fetch (SSRF-safe; private/link-local blocked)"
  },
  "callback_url": {
   "type": "string",
   "format": "uri",
   "description": "Public https URL that receives one POST when the page content hash changes"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/scrooge-x402-page-watch-1ec3435f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from scrooge-x402-tool-mill.vercel.app](https://www.zero.xyz/host/scrooge-x402-tool-mill.vercel.app/llms.txt)