# The Stall — Web Change Monitor

> The Stall — Web Change Monitor is a paid API for AI agents from the-stall.intuitek.ai, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Polls a publicly accessible URL via HTTP GET and detects whether the page content has changed since the last check

## Facts

- Endpoint: GET https://the-stall.intuitek.ai/cap/web-change-monitor
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/the-stall-web-change-monitor-5880f639
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_srSEHpjiRbfw9UHbpYbgZ

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 the-stall-web-change-monitor-5880f639
```

Example prompt: Keep an eye on https://example.com/pricing for me — let me know if the content on that page has changed since the last time you checked it.

## When to prefer this

Use this endpoint when you need a lightweight, pay-per-call web change detection check without setting up accounts, API keys, or a dedicated monitoring subscription. Ideal for one-off or infrequent polling of public URLs, or for integrating change detection into an agent workflow that already uses the x402/USDC payment rail on Base mainnet.

## Known failure modes

- URL is not publicly accessible — returns error or timeout
- Non-HTTPS/HTTP URL provided — schema validation fails
- Target server returns 4xx/5xx — cannot retrieve content to compare
- URL parameter missing from queryParams — required field validation error
- Network timeout reaching the target URL

## How this service works

Returns content-change signals for any public URL: ETag, Last-Modified, Content-Length, and Content-Type via HTTP HEAD. Falls back to GET + SHA-256 of the first 32 KB when the server returns no cache markers. Store the snapshot and re-call periodically to detect changes. Useful for monitoring competitor pricing, news, regulatory filings, or any public page.

## Output

Returns an indication of whether the target URL's content has changed, along with relevant metadata about the current page state such as a content hash, diff, or snapshot that can be compared against a prior state.

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {
   "url": "https://example.com"
  }
 }
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "required": {
   "type": "string"
  },
  "properties": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/the-stall-web-change-monitor-5880f639/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from the-stall.intuitek.ai](https://www.zero.xyz/host/the-stall.intuitek.ai/llms.txt)