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AgentShelf XPath Canonical Href Extractor
x402
AgentShelf XPath Canonical Href Extractor is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-01).
Extracts the canonical URL from a public webpage or raw HTML using the XPath selector //link[@rel='canonical']/@href
Price / call$0.004
Success—
StatusUnknown
How this service works
Call when an agent needs href of link rel exactly canonical via //link[@rel='canonical']/@href from a public page or HTML (SSRF-safe). Exact $0.004 USDC. Prefer unpaid POST /v1/sandbox/xpath-canonical-href first.
Output
Returns the value of the href attribute from the first <link rel='canonical'> element found in the page's HTML, resolved via XPath //link[@rel='canonical']/@href. If no canonical tag is present, returns an empty or null result. The response is a string URL representing the declared canonical page.
Example use cases
SEO canonical audit for a page
“Check https://www.shopify.com/blog/ecommerce-seo and tell me what canonical URL is declared in the page — I want to see if it points to itself or a different URL.”
Deduplication check for crawled content
“I have this HTML snippet from a scraped page — can you find the canonical href in it so I can figure out the authoritative URL before I index it?”
Verify canonical tag after redirect
“After our site migration, can you fetch https://newsite.com/products/widget and confirm what canonical URL is set in the HTML head? I want to make sure the canonical tag was updated correctly.”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/xpath-canonical-href?utm_source=zero.xyzWhen to prefer
Use this endpoint when you specifically need the canonical href from a page's link tags — for SEO auditing, deduplication, or verifying canonical declarations. It is more precise and cheaper than full-page scraping when you only need the canonical URL. Use the sandbox POST /v1/sandbox/xpath-canonical-href first if available to avoid the $0.004 USDC charge.
Side effects
- No canonical link tag exists on the page — returns empty or null result
- URL is unreachable or returns non-200 HTTP status — request fails
- URL points to a private/metadata IP address — rejected by SSRF protection
- HTML input exceeds 200,000 character limit — validation error
- Page requires JavaScript rendering — canonical tag may not be present in static HTML
- Malformed HTML may cause XPath to fail to locate the tag
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| url | string | Public page to fetch. The selector or profile is fixed by the SKU. Provide url or html. |
| html | string | HTML to extract from locally. Provide html or url. When both are set, html is used. |
Tags
x402
Reviews
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