# agentshelf.syntexa.ch XPath Image Alt Extractor

> agentshelf.syntexa.ch XPath Image Alt Extractor is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-24).

Extracts alt attribute values from all img elements on a public webpage or HTML snippet using XPath (//img/@alt), SSRF-safe.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/xpath-img-alt?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-24
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-syntexa-ch-xpath-image-alt-extractor-8fe1be59
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HE-AnrbdVt9f0JmGPID6E

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-syntexa-ch-xpath-image-alt-extractor-8fe1be59 -d '<json body>'
```

Example prompt: Can you pull out all the image alt text from https://example.com/about — I want to see what descriptions every img tag has on that page?

## When to prefer this

Use this endpoint when you need to extract specifically the alt attributes from img elements on a public webpage or HTML string. It is purpose-built for XPath-based alt text extraction and is SSRF-safe. Prefer the free sandbox POST /v1/sandbox/xpath-img-alt endpoint first if available; use this paid version when the sandbox is unavailable or rate-limited. Choose this over general HTML scrapers when you specifically need structured alt attribute data rather than full page content.

## Known failure modes

- URL is not publicly accessible or returns a non-200 status
- SSRF-blocked URL (private IP ranges, localhost) rejected for security
- HTML content exceeds 200,000 character limit
- URL string shorter than 8 characters or longer than 2048 characters
- Page has no img elements, returning empty array
- Malformed HTML that cannot be parsed
- Network timeout fetching the remote URL

## How this service works

Call when an agent needs alt attributes of //img via //img/@alt from a public page or HTML (SSRF-safe). Exact $0.001 USDC. Prefer unpaid POST /v1/sandbox/xpath-img-alt first.

## Output

Returns a list of alt attribute values extracted from all img elements found on the given page or HTML, using the XPath expression //img/@alt. Results may be empty strings where images lack alt attributes.

## 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-syntexa-ch-xpath-image-alt-extractor-8fe1be59/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)