# extract-main-as-json-watch

> extract-main-as-json-watch is a paid API for AI agents from page.intel.rallylive.ca, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-20).

Monitors a web page's main content (as JSON) for changes, returning a diff with before/after values and a changed flag on each call

## Facts

- Endpoint: GET https://page.intel.rallylive.ca/watch/page/main/json?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/extract-main-as-json-watch-41cafccf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_EoEeqUJlkXaEJkqaSlMZI

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 extract-main-as-json-watch-41cafccf
```

Example prompt: Keep an eye on the main content section of https://example.com/products for me — let me know whether anything has changed since the last time you checked, and show me exactly what's different with the before and after values.

## When to prefer this

Choose this endpoint when you need to detect and diff changes in a web page's main content area specifically in JSON format, and want persistent snapshot comparison (up to 90 days of history) without managing your own storage. It is ideal for scheduled agent workflows that need to react to content updates — prefer it over a plain extraction endpoint when the goal is change alerting rather than one-off retrieval, and over general-purpose web monitors when you need structured JSON diffs of the main element specifically.

## Known failure modes

- URL is unreachable or returns a non-200 status — returns an error with no content
- No previous snapshot exists (first call) — returns current content with changed=false and no diff
- Snapshot older than 90 days has been purged — treated as a first call with no diff available
- Page has no identifiable main element — returns empty or null content
- Rate limiting or payment failure — call is rejected before check is performed

## How this service works

Change watch for extract main as json: runs the check, compares it with the result from your previous call for the same url (kept 90 days) and returns the current answer, changed true/false, the fields that changed with before/after values, and when it was last seen. Schedule it to be alerted when this changes. $0.02 per check.

## Output

Returns the current extracted main-element content as JSON, a boolean 'changed' flag indicating whether it differs from the last call for the same URL (stored for 90 days), a list of fields that changed with their before and after values, and a timestamp of when the content was last seen in its prior state.

## 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/extract-main-as-json-watch-41cafccf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from page.intel.rallylive.ca](https://www.zero.xyz/host/page.intel.rallylive.ca/llms.txt)