# Crawlspur Canonical Content-Type Checker

> Crawlspur Canonical Content-Type Checker is a paid API for AI agents from crawlspur.halowerk.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Checks and validates the delivered content type of a canonical URL target for SEO technical auditing.

## Facts

- Endpoint: POST https://crawlspur.halowerk.com/v1/pruef/crawlspur/inhaltstyp/canonical
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/crawlspur-canonical-content-type-checker-e960e5e6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gd7wmNJ7V0E7E78G8y8pb

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 crawlspur-canonical-content-type-checker-e960e5e6 -d '<json body>'
```

Example prompt: Check the delivered content type for the canonical URL https://example.com/my-page and tell me if it's returning the expected HTML content type.

## When to prefer this

Choose this endpoint when you specifically need to audit the HTTP content-type returned by a canonical URL as part of a technical SEO crawl — for example, to detect pages where the canonical points to a non-HTML resource, a redirect chain, or an unexpected MIME type. It is part of a suite of specialized SEO checks on crawlspur.halowerk.com and is best used in automated SEO auditing pipelines.

## Known failure modes

- Target URL is unreachable or returns a network error
- URL is not publicly accessible (private/intranet)
- Input URL is malformed or exceeds 2048 characters
- CSS selector matches no element or returns ambiguous results
- Canonical tag not found on target page
- Payment authorization fails (x402 protocol error)
- Rate limiting or server-side blocking of the crawler user agent

## How this service works

Prüft am Objekt canonical den Befund ausgelieferten Inhaltstyp.

## Output

Returns a structured finding (Befund) describing the delivered content type of the inspected canonical object — typically including the MIME type returned by the canonical URL's HTTP response, any anomalies, and relevant status information for technical SEO evaluation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "ziel": {
   "oneOf": [
    {
     "type": "string",
     "maxLength": 2048,
     "minLength": 1,
     "description": "Öffentliche HTTP(S)-Adresse; bei DNS-Befunden Domain oder öffentliche IP."
    },
    {
     "type": "object",
     "required": [
      "adresse"
     ],
     "properties": {
      "adresse": {
       "type": "string",
       "maxLength": 2048,
       "minLength": 1
      },
      "selektor": {
       "type": "string",
       "maxLength": 240,
       "minLength": 1,
       "description": "CSS-Selektor: genau ein Objekt, sonst erster Treffer des Objektfilters."
      },
      "vergleich": {
       "type": "string",
       "maxLength": 2048,
       "description": "Öffentliche Vergleichsadresse für Link-, Sitemap- oder Sprachbefunde."
      },
      "user_agent": {
       "type": "string",
       "pattern": "^[A-Za-z0-9_-]{1,80}$"
      },
      "dkim_selektor": {
       "type": "string",
       "pattern": "^[A-Za-z0-9_-]{1,63}$"
      }
     },
     "additionalProperties": false
    }
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/crawlspur-canonical-content-type-checker-e960e5e6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from crawlspur.halowerk.com](https://www.zero.xyz/host/crawlspur.halowerk.com/llms.txt)