# Canonical URL Declarations — Joined Text Extraction

> Canonical URL Declarations — Joined Text Extraction 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).

Statically parses a web page or supplied HTML to extract the joined text content associated with canonical URL declaration elements, filtered by a specified attribute and search term.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-bx-web-canonical-text?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-joined-text-extraction-81da14c8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_H7nGXWSpIpqqENOqYXM_w

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-joined-text-extraction-81da14c8 -d '<json body>'
```

Example prompt: Extract the joined text from the canonical URL declaration element with id 'main-canonical' on https://example.com/product-page — use 'product' as the search term and check against these previously seen texts: ['Old canonical text'].

## When to prefer this

Choose this endpoint when you need to statically extract text from canonical URL declaration elements in a page's HTML without JavaScript rendering, login, or browser emulation. It is ideal for lightweight SEO audits, canonical tag checks, and metadata extraction where the canonical link element is present in the raw HTML. Prefer it over full browser-based scrapers when speed and cost matter and the target content does not require JavaScript to render.

## Known failure modes

- URL is inaccessible or returns non-200 status — extraction fails with no result
- JavaScript-rendered content not visible — static parser only sees initial HTML
- No matching canonical element found for the given attribute/value pair — empty result returned
- HTML payload exceeds 100,000 character limit — request rejected
- Invalid attribute name pattern — request fails schema validation
- URL exceeds 2048 character limit — request rejected

## How this service works

Canonical URL declarations — Joined text extraction: Joined text extraction 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 joined text extraction result.

## Output

Returns a bounded joined text extraction result containing the text content found within canonical URL declaration elements on the target page or HTML, matched by the specified attribute name and value, with deduplication context from previously seen texts.

## 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-joined-text-extraction-81da14c8/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)