# Crawlspur robots.txt Canonical Allowance Check

> Crawlspur robots.txt Canonical Allowance Check 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 whether the canonical URL of a given page is permitted (not blocked) by the site's robots.txt rules.

## Facts

- Endpoint: POST https://crawlspur.halowerk.com/v1/pruef/crawlspur/robots-erlaubt/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-robots-txt-canonical-allowance-check-6c6b6b9d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dVj271OGuaRBpA2ZZxDVs

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-robots-txt-canonical-allowance-check-6c6b6b9d -d '<json body>'
```

Example prompt: Check whether the canonical URL https://example.com/blog/my-article is allowed by the site's robots.txt — I need to know if crawlers are permitted to access it.

## When to prefer this

Use this endpoint when you specifically need to verify robots.txt crawl permission for a canonical URL — particularly in SEO workflows where canonical tag correctness intersects with crawl access, or when diagnosing why a canonical page is not being indexed. Prefer this over generic robots.txt checkers when the canonical object type is your focus.

## Known failure modes

- Invalid or non-public URL returns an error or unresolvable address finding
- robots.txt file absent or unreachable results in an inconclusive or error response
- Malformed CSS selector causes first-match fallback or error
- URL exceeds 2048 character limit returns validation error
- Non-HTTP(S) addresses are rejected

## How this service works

Prüft am Objekt canonical den Befund Freigabe durch robots.txt.

## Output

Returns a finding indicating whether the canonical URL is permitted or blocked by the site's robots.txt, including the specific rule or directive responsible for the outcome.

## 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-robots-txt-canonical-allowance-check-6c6b6b9d/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)