# Table Header Cells — Attribute Presence Check

> Table Header Cells — Attribute Presence Check is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-11).

Checks whether a specified HTML attribute (and optionally a specific attribute value) is present on table header cells matching a search term in a given webpage or HTML snippet.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-bx-web-table-headers-attribute-presence?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/table-header-cells-attribute-presence-check-0496e5f4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_MV9qXQR15DFOdGYG54M0c

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 table-header-cells-attribute-presence-check-0496e5f4 -d '<json body>'
```

Example prompt: Check if the table header cell containing the word 'product' on this page https://example.com/catalog has an 'id' attribute with the value 'sample'.

## When to prefer this

Choose this endpoint when you need a cheap, fast, statically-parsed check for a specific HTML attribute on table header cells — ideal for accessibility audits, QA pipelines, or automated markup validation where JavaScript rendering is not required and you only need a presence/value check rather than full table extraction.

## Known failure modes

- URL is unreachable or returns non-200 status — no HTML to parse
- No table header cells found in the page or HTML snippet
- Search term does not match any th element text — empty result
- Attribute name fails regex validation (must start with a letter)
- HTML exceeds 100,000 character limit — input rejected
- URL exceeds 2,048 character limit — input rejected
- Page requires JavaScript rendering — static parser returns incomplete DOM

## How this service works

Table header cells — Attribute presence check: Attribute presence check for Table header cells. 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 attribute presence check result.

## Output

Returns a bounded attribute presence check result indicating whether the specified attribute (and optionally its value) exists on table header cells that match the provided search term, parsed statically from the supplied URL or raw HTML without JavaScript rendering.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "default": "",
   "maxLength": 2048
  },
  "html": {
   "type": "string",
   "default": "<!doctype html><html><head></head><body><table><tbody><tr><th id=\"sample\">Example product guide</th></tr></tbody></table></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/table-header-cells-attribute-presence-check-0496e5f4/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)