# main-image-detect-watch

> main-image-detect-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 webpage's main image for changes by comparing the current result against a stored previous result, returning a diff with changed fields and timestamps.

## Facts

- Endpoint: GET https://intel.rallylive.ca/watch/page/main-image
- 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/main-image-detect-watch-80604e28
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ykCQC-sbRt7lSlOStoB3R

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 main-image-detect-watch-80604e28
```

Example prompt: Keep an eye on https://example.com for me — let me know if the main image on that page ever changes compared to the last time you checked.

## When to prefer this

Use this endpoint when you need to detect changes in a webpage's main image over time on a polling or scheduled basis. It is ideal for monitoring competitor product pages, landing pages, news sites, or any URL where the primary visual content matters. Unlike a one-shot image extraction, this endpoint maintains a 90-day history per URL and returns a structured diff, making it the right choice when you need to know not just the current image but whether and exactly how it changed since your last check.

## Known failure modes

- URL is unreachable or returns a non-200 status — check may return an error or null image result
- No previous result stored for the URL (first call) — changed flag may be false or undefined since there is no baseline to compare against
- Page has no detectable main image — returns empty or null image fields
- URL stored result has expired after 90 days — diff baseline is reset
- Malformed or non-HTTP URL input — request fails validation

## How this service works

Change watch for main image detect: 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 main image of a page changes. $0.01 per check.

## Output

Returns the current main image detected on the page, a boolean indicating whether it changed since the last call for the same URL, a field-level diff showing exactly which properties changed with before and after values, and the timestamp of when the image 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/main-image-detect-watch-80604e28/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)