# Website Changes Detector

> Website Changes Detector is a paid API for AI agents from agent.chiemgaufilms.com, paid per call via x402, $0.025/call, status unknown (last checked 2026-10-29).

Fetches a single webpage, extracts its main-topic text, and compares it line-by-line against a caller-supplied previous snapshot to report added and removed lines.

## Facts

- Endpoint: POST https://agent.chiemgaufilms.com/api/v1/website-changes?utm_source=zero.xyz
- Price: $0.025/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/website-changes-detector-9c0d145f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DoF4teXfxf3NmGQFUlk4B

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-changes-detector-9c0d145f -d '<json body>'
```

Example prompt: Check whether https://example.com/news has changed since my last visit — here's the snapshot text I saved previously: 'Welcome to our news page. Latest update: March 1.' Tell me what lines were added or removed.

## When to prefer this

Choose this endpoint when you need a one-shot, lightweight comparison of a single webpage's current text against a known previous state you already have stored. It is ideal for agent workflows that maintain their own snapshots and want to detect textual changes without setting up a scheduler or crawling multiple pages. Prefer it over full-site monitoring tools when you only care about line-level text diffs of a bounded content area, and you do not need screenshots, semantic interpretation, or automatic periodic polling.

## Known failure modes

- URL is unreachable or returns a non-200 status — endpoint may return an error or empty diff
- Previous snapshot text exceeds 12,000 character limit — request will be rejected
- URL string exceeds 2,000 character limit — request will be rejected
- Page has no extractable main-topic text (e.g. fully JavaScript-rendered with no SSR) — diff may be empty or inaccurate
- Snapshot URL and current URL mismatch may produce misleading diffs if content is unrelated
- Network timeout fetching the target page — transient failure

## How this service works

Fetch one page once and compare its bounded main-topic text with a caller-supplied previous snapshot for the same URL. Reports added/removed lines. No scheduler, screenshots or whole-site crawl; no semantic price interpretation.

## Output

Returns a structured diff of the webpage's main-topic text versus the supplied previous snapshot, listing lines that were added and lines that were removed. No screenshots, no scheduled polling, and no semantic interpretation of the changes (e.g. no price parsing) — just raw line-level additions and deletions.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "maxLength": 2000
  },
  "previous": {
   "type": "object",
   "required": [
    "url",
    "text"
   ],
   "properties": {
    "url": {
     "type": "string",
     "maxLength": 2000
    },
    "text": {
     "type": "string",
     "maxLength": 12000
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/website-changes-detector-9c0d145f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent.chiemgaufilms.com](https://www.zero.xyz/host/agent.chiemgaufilms.com/llms.txt)