# H4 Attribute Values Extractor

> H4 Attribute Values Extractor is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-13).

Extracts distinct values of a specified HTML attribute from all H4 heading elements on a given web page or HTML snippet.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-bx-web-h4-attribute-values?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/h4-attribute-values-extractor-113aa624
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JTbMkuZ16WFfHbLH1DPPJ

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 h4-attribute-values-extractor-113aa624 -d '<json body>'
```

Example prompt: Parse this HTML snippet and give me all the distinct values of the 'data-kind' attribute found on H4 headings, filtering for ones related to 'product': <!doctype html><html><head></head><body><h4 id="sample" data-kind="example">Example product guide</h4></body></html>

## When to prefer this

Choose this endpoint when you need to enumerate distinct HTML attribute values specifically from H4 heading elements on a static web page or known HTML fragment, particularly when you want a lightweight, cost-effective extraction (one bounded result per call at $0.01 USDC) without needing JavaScript rendering or authenticated page access.

## Known failure modes

- URL is unreachable or returns non-200 status — no content to parse
- No H4 elements found in the document — empty result set
- Specified attribute does not appear on any H4 element — empty distinct values
- HTML exceeds 100,000 character limit — request rejected
- Attribute name fails regex validation (must start with letter, max 50 chars) — validation error
- JavaScript-rendered content not available since only static HTML is parsed

## How this service works

Level-four headings — Distinct attribute values: Distinct attribute values for Level-four headings. One public HTTPS page or supplied HTML; static parsing, no JavaScript rendering, login or access bypass. Specialised preset in a shared 50-profile, 20-operation engine. 0.01 USDC includes one bounded distinct attribute values result.

## Output

Returns a bounded set of distinct values for the specified HTML attribute found across all H4 heading elements in the provided URL's page content or supplied HTML snippet, filtered by the given search term context.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "default": "",
   "maxLength": 2048
  },
  "html": {
   "type": "string",
   "default": "<!doctype html><html><head></head><body><h4 id=\"sample\" data-kind=\"example\">Example product guide</h4></body></html>",
   "maxLength": 100000
  },
  "term": {
   "type": "string",
   "default": "product",
   "maxLength": 100,
   "minLength": 1
  },
  "attribute": {
   "type": "string",
   "default": "id",
   "pattern": "^[a-zA-Z][a-zA-Z0-9:_-]{0,49}$",
   "maxLength": 50
  },
  "previous_texts": {
   "type": "array",
   "items": {
    "type": "string",
    "default": "",
    "maxLength": 1000
   },
   "default": [
    "Older example"
   ],
   "maxItems": 200,
   "minItems": 0
  },
  "attribute_value": {
   "type": "string",
   "default": "sample",
   "maxLength": 200
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/h4-attribute-values-extractor-113aa624/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)