# Canonical URL Declarations — Text Length Statistics

> Canonical URL Declarations — Text Length Statistics is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-21).

Parses a public webpage or supplied HTML to extract text length statistics for canonical URL declaration elements, without JavaScript rendering or login.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-bx-web-canonical-lengths?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/canonical-url-declarations-text-length-statistics-04586a18
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_PQx460_hjcfPZi_V3ng9U

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-statistics-04586a18 -d '<json body>'
```

Example prompt: Can you parse the page at https://example.com/product-page and give me text length statistics for all the canonical URL declarations — specifically looking at elements with the attribute id equal to 'canonical-main'?

## When to prefer this

Choose this endpoint when you need lightweight, static HTML parsing specifically focused on text length statistics for canonical URL declaration elements on a page, without needing JavaScript rendering or authenticated access. It is well-suited for SEO auditing workflows, HTML validation pipelines, and agents that need fast, cheap per-page canonical tag analysis at $0.01 per call.

## Known failure modes

- URL is not publicly accessible or returns a non-200 HTTP status
- HTML exceeds 100,000 character limit
- No canonical URL declarations found matching the specified attribute/value
- URL or HTML input malformed or missing
- Attribute name does not match pattern requirements
- previous_texts array exceeds 200 items

## How this service works

Canonical URL declarations — Text length statistics: Text length statistics 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 statistics result.

## Output

Returns a bounded text length statistics result covering the canonical URL declaration elements found in the parsed page or HTML, including computed metrics such as character counts and related text length measures for matching elements.

## 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-statistics-04586a18/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)