# Syntexa AgentShelf Hreflang List Extractor

> Syntexa AgentShelf Hreflang List Extractor is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-01).

Extracts all hreflang alternate link elements from a public URL or raw HTML, returning a structured list of language/region alternates.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/hreflang-list?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/syntexa-agentshelf-hreflang-list-extractor-6d79e380
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oNg5F70mB83zkQyVwuBZs

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 syntexa-agentshelf-hreflang-list-extractor-6d79e380 -d '<json body>'
```

Example prompt: Can you pull all the hreflang alternate tags from https://www.example.com/about so I can see what language and region versions they're targeting?

## When to prefer this

Choose this endpoint when you need to programmatically extract hreflang alternate link data from a live URL or raw HTML for SEO auditing, internationalization analysis, or localization research. It is SSRF-safe for fetching public URLs and accepts raw HTML if you already have the markup. Prefer the free POST /v1/sandbox/hreflang-list first for testing; use this paid endpoint ($0.003 USDC) for production workloads or when the sandbox is unavailable.

## Known failure modes

- URL is unreachable or returns non-200 status — fetch error returned
- HTML content exceeds 200,000 character limit — input rejected
- URL is blocked by SSRF safety rules (private/internal addresses) — request refused
- No hreflang tags present in page — empty list returned
- Malformed HTML causes parsing failure — error or partial results
- URL shorter than 8 characters or longer than 2048 characters — validation error

## How this service works

Call when an agent needs hreflang alternates extracted from a public page or HTML (SSRF-safe). Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/hreflang-list first.

## Output

A structured list of hreflang alternate entries found on the page, each including the hreflang attribute value (language/region code, e.g. 'en-US', 'fr', 'x-default') and the corresponding alternate URL. Returns an empty list if no hreflang tags are found.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "maxLength": 2048,
   "minLength": 8,
   "description": "Public http(s) URL to fetch. When html is also sent, this is only the base for relative links. Provide url or html."
  },
  "html": {
   "type": "string",
   "examples": [
    "<link rel=\"alternate\" hreflang=\"en\" href=\"https://example.com/en\">"
   ],
   "maxLength": 200000,
   "minLength": 1,
   "description": "HTML to parse locally instead of fetching. When both html and url are set, html is used. Provide html or url."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/syntexa-agentshelf-hreflang-list-extractor-6d79e380/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)