# AgentShelf HTML Lang Attribute Extractor

> AgentShelf HTML Lang Attribute Extractor is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-28).

Extracts the `lang` attribute value from the `<html>` element of a given public webpage URL or raw HTML string, in an SSRF-safe manner.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/profile-html-lang?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-html-lang-attribute-extractor-85d9dff7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mYPQEaJCzAgqulWXWms8y

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 agentshelf-html-lang-attribute-extractor-85d9dff7 -d '<json body>'
```

Example prompt: Can you extract the HTML lang attribute from https://www.example.com so I know what language the page declares?

## When to prefer this

Use this endpoint when you need to programmatically determine the declared language of a webpage or HTML fragment via the `<html lang>` attribute, particularly for SEO audits, accessibility checks, or internationalization validation. Prefer the free sandbox variant (/v1/sandbox/profile-html-lang) for testing. Use this paid endpoint when the sandbox is unavailable or when making production calls. Choose sibling endpoints if you need other HTML metadata such as og:title, canonical links, or anchor hrefs.

## Known failure modes

- URL is unreachable or returns a non-200 HTTP status
- SSRF guard blocks private/internal IP addresses or metadata endpoints
- HTML has no lang attribute on the html element — returns empty result
- HTML string exceeds 200,000 character limit
- Neither url nor html provided — schema validation error
- Malformed or non-HTML content at the given URL

## How this service works

Call when an agent needs the html lang attribute extracted from a public page or HTML (SSRF-safe). Exact $0.002 USDC. Prefer unpaid POST /v1/sandbox/profile-html-lang first.

## Output

Returns the value of the `lang` attribute found on the root `<html>` element of the fetched or provided HTML document (e.g. 'en', 'fr', 'zh-CN'). If the attribute is absent or the page cannot be fetched, returns an empty or error response.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "maxLength": 2048,
   "minLength": 8,
   "description": "Public page to fetch. The selector or profile is fixed by the SKU. Provide url or html."
  },
  "html": {
   "type": "string",
   "examples": [
    "<!doctype html><html lang=\"en\"><head><title>Hello</title>\n<meta name=\"description\" content=\"Desc\"><meta property=\"og:title\" content=\"OG\">\n<link rel=\"canonical\" href=\"https://example.com/\"><link rel=\"icon\" href=\"/favicon.ico\">\n</head><body><h1>Hello</h1><a href=\"https://example.com/a\">A</a></body></html>"
   ],
   "maxLength": 200000,
   "minLength": 1,
   "description": "HTML to extract from locally. Provide html or url. When both are set, html is used."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentshelf-html-lang-attribute-extractor-85d9dff7/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)