# Fresh402 Web Change Monitor

> Fresh402 Web Change Monitor is a paid API for AI agents from fresh402.kirilllabs.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).

Checks whether a web page has materially changed since its last snapshot, filtering out common page noise, and updates the stored snapshot.

## Facts

- Endpoint: POST https://fresh402.kirilllabs.workers.dev/v1/check?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fresh402-web-change-monitor-832cd6ae
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_F1c3fBcstYfYPVGhCgrIW

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 fresh402-web-change-monitor-832cd6ae -d '<json body>'
```

Example prompt: Check if the page at https://example.com/pricing has materially changed since the last time Fresh402 snapshotted it — ignore things like timestamps or ad banners and just tell me if the real content is different.

## When to prefer this

Choose this endpoint when you need to detect meaningful content changes on a web page over repeated visits while suppressing common dynamic noise (timestamps, ads, session data). It is ideal for monitoring competitor pages, regulatory publications, news articles, or any URL where you care about substantive content updates rather than cosmetic or technical churn. Prefer it over generic scraping tools when you want built-in change-diffing with snapshot management rather than raw HTML retrieval.

## Known failure modes

- URL is unreachable or returns a non-200 status — endpoint may return an error or indicate the page could not be fetched
- First call for a URL has no prior snapshot to compare against — may return a baseline-established response rather than a change signal
- Page blocks automated access (bot detection, CAPTCHA) — content may be unavailable for comparison
- Network timeouts for slow-loading pages
- Overly aggressive noise filtering may miss subtle but meaningful changes

## How this service works

Detect meaningful content changes in any URL, monitor website and web page changes, check page freshness, filter common boilerplate/noise, and return a change signal for AI agents.

## Output

Returns whether the target web page has materially changed since its previous Fresh402 snapshot, with noise (dynamic elements like timestamps, ads, session tokens) filtered out. The snapshot is updated on each call so subsequent checks compare against the latest version.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "format": "uri",
   "description": "Absolute HTTP or HTTPS URL to monitor. Send the same URL again to detect meaningful page changes since the previous Fresh402 snapshot."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fresh402-web-change-monitor-832cd6ae/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fresh402.kirilllabs.workers.dev](https://www.zero.xyz/host/fresh402.kirilllabs.workers.dev/llms.txt)