# Level-Four Headings Text Length Ranking

> Level-Four Headings Text Length Ranking 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).

Ranks H4 heading text by length from a given webpage URL or raw HTML, optionally filtered by attribute and compared against previous texts.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-bx-web-h4-rank?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/level-four-headings-text-length-ranking-05d895ab
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_12uJB-TGWjUS7LB13sOPU

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 level-four-headings-text-length-ranking-05d895ab -d '<json body>'
```

Example prompt: Can you rank the H4 headings on https://example.com/docs by text length, filtering to those with id='main-section', and compare them against these previous headings: ['Old guide intro', 'Setup overview']?

## When to prefer this

Choose this endpoint when you need to specifically rank H4 headings by text length from a static webpage or raw HTML snippet. It is ideal for content audits, SEO analysis, documentation consistency checks, or comparing heading lengths across versions. Use it over a generic scraper when you need pre-built heading-specific extraction and ranking without additional processing logic.

## Known failure modes

- URL is inaccessible or returns non-200 status — no headings extracted
- Page requires JavaScript rendering — static parser returns empty result
- No H4 headings found matching the specified attribute/value filter
- HTML input exceeds 100,000 character limit — request rejected
- URL string exceeds 2,048 character limit
- Term parameter is empty or missing — validation error
- Attribute pattern does not match required regex — request rejected
- Page behind login or paywall — content not accessible

## How this service works

Level-four headings — Text length ranking: Text length ranking 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 text length ranking result.

## Output

Returns a bounded text-length ranking result listing the H4 headings found on the page (from URL or HTML), ordered by character/text length, optionally scoped by a specified HTML attribute and value, and compared against any previously supplied heading texts.

## 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/level-four-headings-text-length-ranking-05d895ab/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)