# html-fetch-watch

> html-fetch-watch is a paid API for AI agents from intel.rallylive.ca, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Monitors a URL for changes in raw HTML content by comparing the current fetch result against the previous cached result, returning a changed flag and diff of modified fields.

## Facts

- Endpoint: GET https://intel.rallylive.ca/watch/page/html
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/html-fetch-watch-c73b1aa0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_C_-l03F4D0MlLdSFxTtw8

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 html-fetch-watch-c73b1aa0
```

Example prompt: Watch https://example.com/pricing for me using a GET request and tell me if the raw HTML has changed since last time, and exactly what fields are different now.

## When to prefer this

Use this endpoint when you need to detect changes in raw HTML content of a specific URL over time without building your own diffing or storage infrastructure. It is ideal for scheduled monitoring workflows where you want a simple changed/unchanged signal plus a structured diff of what exactly changed. Prefer this over a plain HTML fetch when you need change detection logic built in, and over a full web crawler when you only need to watch a single URL.

## Known failure modes

- URL is unreachable or returns a non-200 status — current fetch may fail or return error state
- No prior cached result exists for the URL (first call) — changed flag may be null or false by default
- Cached result has expired beyond 90 days — comparison baseline is lost
- URL redirects or changes domain — may compare against stale baseline
- Rate limiting or network timeouts on the target URL — fetch may be incomplete

## How this service works

Change watch for html fetch: runs the check and compares it with the result from your previous call for the same url (kept 90 days), returning the current answer, changed true/false, exactly which fields changed with before/after values, and when it was last seen. Call it on a schedule to be told when raw html fetch changes. $0.01 per check.

## Output

Returns the current raw HTML fetch result, a boolean 'changed' flag indicating whether the content differs from the previous call for the same URL, a list of exactly which fields changed with their before and after values, and a timestamp of when the previous result was last seen. Previous results are retained for 90 days.

## 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",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/html-fetch-watch-c73b1aa0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from intel.rallylive.ca](https://www.zero.xyz/host/intel.rallylive.ca/llms.txt)