# Articles — Invisible Character Flags

> Articles — Invisible Character Flags is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-21).

Detects and flags invisible Unicode characters within article elements on a web page or supplied HTML snippet.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-bx-web-articles-unicode?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/articles-invisible-character-flags-ea06f78e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_K0zY-IdfeVAPA-k6zi01H

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 articles-invisible-character-flags-ea06f78e -d '<json body>'
```

Example prompt: Can you scan the article on https://example.com/blog/my-post for any invisible Unicode characters — look inside the element with id 'main-article' and compare against these previous versions of the text?

## When to prefer this

Choose this endpoint when you need to detect invisible or hidden Unicode characters specifically within article-type HTML elements on a public web page or a provided HTML string, without requiring JavaScript rendering or authentication. It is well-suited for content integrity checks, pre-publication audits, and detecting steganographic or formatting anomalies in article text. Prefer alternatives if you need full-page Unicode scanning outside article elements or JavaScript-rendered content analysis.

## Known failure modes

- URL is behind a login or paywall — endpoint cannot bypass authentication, returns empty or error
- JavaScript-rendered content not parsed — dynamically injected article text will be missed
- HTML exceeds 100,000 character limit — request rejected
- URL is unreachable or returns non-200 status — fetch fails
- Attribute pattern mismatch — attribute field must match ^[a-zA-Z][a-zA-Z0-9:_-]{0,49}$ or request is rejected
- Term field empty or missing — minLength of 1 enforced, blank term causes validation error

## How this service works

Articles — Invisible character flags: Invisible character flags for Articles. 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 invisible character flags result.

## Output

Returns a bounded result set identifying any invisible or non-printable Unicode characters found within the targeted article element of the provided URL or HTML, including their positions and character types, based on static HTML parsing 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><article id=\"sample\" data-kind=\"example\">Example product guide</article></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/articles-invisible-character-flags-ea06f78e/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)