# Entity Extract Heuristic Change Watch

> Entity Extract Heuristic Change 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 heuristic-extracted named entities for changes over time, returning a diff of added/removed/modified entity fields between the current and previous check.

## Facts

- Endpoint: GET https://intel.rallylive.ca/watch/page/entities
- 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/entity-extract-heuristic-change-watch-73e645c6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_PUD07eZNpnp4zrdlm96gh

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 entity-extract-heuristic-change-watch-73e645c6
```

Example prompt: Keep an eye on the page at https://example.com/about-us and let me know whenever the named entities — like people, companies, or places mentioned — change compared to the last time you checked.

## When to prefer this

Choose this endpoint when you need to detect changes in heuristic (non-LLM) named entity extraction from a specific URL over time without requiring an LLM-powered analysis. It is ideal for scheduled monitoring workflows where you want lightweight, cost-effective ($0.01/check) entity change detection with field-level diffs. Prefer it over one-shot entity extraction when change detection and historical comparison are the primary goals.

## Known failure modes

- URL is unreachable or returns a non-200 response, causing the check to fail with no result
- No previous result exists yet (first call), so `changed` will be false or undefined
- The 90-day history window has expired, losing the prior comparison baseline
- The page uses heavy JavaScript rendering, reducing heuristic entity extraction accuracy
- Transient network errors may cause incomplete or missing entity extraction

## How this service works

Change watch for entity extract heuristic: 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 named-entity candidates from a page without an llm changes. $0.01 per check.

## Output

Returns the current heuristic-extracted named entity candidates from the page, a boolean `changed` flag indicating whether results differ from the previous call for the same URL, a field-level diff showing exactly which entity fields changed with before and after values, and the timestamp of when the previous result was last seen. The previous result is 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/entity-extract-heuristic-change-watch-73e645c6/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)