# AgentShelf XPath H3 Extractor

> AgentShelf XPath H3 Extractor is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-02).

Extracts all h3 heading text from a public web page or raw HTML using XPath, with SSRF protection.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/xpath-h3?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-xpath-h3-extractor-ecb1cce9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8X7CvW2cOpy12_KA_FJGU

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-xpath-h3-extractor-ecb1cce9 -d '<json body>'
```

Example prompt: Can you pull all the h3 headings from https://example.com/blog/article and give me a list of the text?

## When to prefer this

Use this endpoint when you specifically need h3-level headings only, rather than all heading levels (h1–h6). Prefer this over a general headings endpoint when you want a narrower, structured extraction of subheadings. Choose the paid /v1/xpath-h3 only after exhausting the free /v1/sandbox/xpath-h3 alternative. Best suited when you already have raw HTML or a public URL and need a lightweight, SSRF-safe extraction without running your own parser.

## Known failure modes

- URL points to a private/internal IP range and is rejected (SSRF protection)
- URL is unreachable or returns a non-200 response
- HTML is malformed and no h3 elements can be parsed
- Input exceeds maxLength constraints (URL > 2048 chars or HTML > 200000 chars)
- Page requires JavaScript rendering and h3 elements are injected dynamically (not present in raw HTML)

## How this service works

Call when an agent needs text of //h3 via //h3 from a public page or HTML (SSRF-safe). Exact $0.01 USDC. Prefer unpaid POST /v1/sandbox/xpath-h3 first.

## Output

A list of text strings, one per h3 element found in the page or HTML, in document order. Returns an empty list if no h3 elements are present.

## 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-xpath-h3-extractor-ecb1cce9/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)