# Canonical URL Declarations — Text Length Ranking

> Canonical URL Declarations — Text Length Ranking is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-13).

Parses a web page or HTML snippet to extract canonical URL declarations and ranks the matched element's text by length against a list of previous texts.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-bx-web-canonical-rank?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/canonical-url-declarations-text-length-ranking-92ae4a07
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_B4mnyitb6iNcd-_c7Hyzh

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 canonical-url-declarations-text-length-ranking-92ae4a07 -d '<json body>'
```

Example prompt: Check the canonical URL declaration on https://example.com/product-page for the element with id 'main-canonical', extract its text, and rank its length against these previous texts: ['Older example', 'Another version'] — use 'product' as the search term.

## When to prefer this

Choose this endpoint when you need a lightweight, static parse of a single page's canonical URL HTML element and want to rank its text length against a historical or comparative list of texts — particularly useful for SEO monitoring, regression tracking of canonical tags, or validating canonical declarations in HTML drafts without needing JavaScript rendering or full browser execution.

## Known failure modes

- URL is unreachable or returns non-200 HTTP status — parsing fails with no result
- Page requires JavaScript rendering — static parser returns empty or incomplete canonical data
- No element matches the specified attribute and attribute_value — ranking cannot be performed
- HTML input exceeds 100,000 character limit — request rejected
- Previous texts array exceeds 200 items — request rejected
- Malformed HTML input — parser may return unexpected or empty results

## How this service works

Canonical URL declarations — Text length ranking: Text length ranking for Canonical URL declarations. One public HTTPS page or supplied HTML; static parsing, no JavaScript rendering, login or access bypass. Specialised preset in a shared 50-profile, 20-operation engine. 0.01 USDC includes one bounded text length ranking result.

## Output

Returns a bounded text length ranking result indicating where the canonical URL element's extracted text falls in length relative to the provided list of previous texts, along with the rank position and relevant length metrics.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "default": "",
   "maxLength": 2048
  },
  "html": {
   "type": "string",
   "default": "<!doctype html><html><head></head><body><link rel=\"canonical\" href=\"https://www.iana.org/help/example-domains\" id=\"sample\"></body></html>",
   "maxLength": 100000
  },
  "term": {
   "type": "string",
   "default": "product",
   "maxLength": 100,
   "minLength": 1
  },
  "attribute": {
   "type": "string",
   "default": "id",
   "pattern": "^[a-zA-Z][a-zA-Z0-9:_-]{0,49}$",
   "maxLength": 50
  },
  "previous_texts": {
   "type": "array",
   "items": {
    "type": "string",
    "default": "",
    "maxLength": 1000
   },
   "default": [
    "Older example"
   ],
   "maxItems": 200,
   "minItems": 0
  },
  "attribute_value": {
   "type": "string",
   "default": "sample",
   "maxLength": 200
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/canonical-url-declarations-text-length-ranking-92ae4a07/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)