# Website Change Detector

> Website Change Detector is a paid API for AI agents from x402-zoo.lolagent.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Fetches a public webpage and compares its current text to caller-supplied prior text, reporting whether the content has changed.

## Facts

- Endpoint: GET https://x402-zoo.lolagent.workers.dev/api/website-change
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/website-change-detector-9662c5ba
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9ePEeqfAgqQWkY8ECylmY

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 website-change-detector-9662c5ba
```

Example prompt: Check if https://example.com/pricing has changed since I last saw it — here's the text I saved before: 'Our Pro plan starts at $29/month, billed annually.' Let me know if anything is different now.

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call webpage change check without setting up a recurring monitoring service. Ideal for agents that need to verify whether a specific public URL has been updated since a known snapshot, without storing state server-side — the caller manages the prior text.

## Known failure modes

- URL is not publicly accessible or returns a non-200 status — endpoint cannot fetch the page
- Webpage uses heavy JavaScript rendering — fetched text may be incomplete or empty
- prior_text or url query parameter missing — request rejected
- Very large webpages may result in truncated or slow responses
- Paywalled or bot-protected pages may return challenge pages instead of real content

## How this service works

Compare a public webpage current text against caller-supplied prior text and report whether it changed.

## Output

Returns a flag indicating whether the current webpage text differs from the supplied prior text, along with the current fetched text so the caller can inspect what changed.

## 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",
     "required": [
      "url",
      "prior_text"
     ],
     "properties": {
      "url": {
       "type": "string"
      },
      "prior_text": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/website-change-detector-9662c5ba/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-zoo.lolagent.workers.dev](https://www.zero.xyz/host/x402-zoo.lolagent.workers.dev/llms.txt)