# Code Block Extract Change Watch

> Code Block Extract 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 code blocks for changes, returning current extracted code, a changed flag, field-level before/after diffs, and last-seen timestamp.

## Facts

- Endpoint: GET https://intel.rallylive.ca/watch/page/codeblocks
- 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/code-block-extract-change-watch-e06dbcd4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dSFLobZtDzc9Exc-r8rYv

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 code-block-extract-change-watch-e06dbcd4
```

Example prompt: Keep an eye on https://docs.example.com/quickstart for me — let me know whenever the code blocks on that page change compared to last time you checked.

## When to prefer this

Choose this endpoint when you need to detect changes specifically in code blocks (pre, code tags) on a webpage over time, rather than monitoring general page content or structured data. It is ideal for scheduled agent workflows that need to track documentation, tutorials, or API reference pages for code sample updates, and provides granular field-level diffs so you know exactly what changed rather than just that something changed.

## Known failure modes

- URL is unreachable or returns a non-200 status — extraction fails with an error
- Page has no code blocks — returns empty extraction with changed=false on first call
- First call for a URL has no prior snapshot to compare against — changed may default to false or null
- Page requires authentication or JavaScript rendering — code blocks may not be extractable
- 90-day retention window exceeded — previous snapshot lost, comparison resets

## How this service works

Change watch for code block extract: 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 code block extraction from a page changes. $0.01 per check.

## Output

Returns the current code block extraction from the page, a boolean 'changed' field indicating whether anything differs from the previous call for the same URL, a list of specific fields that changed with their before and after values, and the timestamp of when the page was last seen. Results from previous calls are retained for 90 days for comparison.

## 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/code-block-extract-change-watch-e06dbcd4/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)