# Code Snippets — Invisible Character Flags

> Code Snippets — 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).

Scans a webpage or HTML snippet containing code elements and detects invisible/hidden Unicode characters within them

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-bx-web-code-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/code-snippets-invisible-character-flags-50dc0e7f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ymI0YIoGuZp7O7rHbpYOw

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 code-snippets-invisible-character-flags-50dc0e7f -d '<json body>'
```

Example prompt: Can you scan the code snippets on https://docs.example.com/api-guide and flag any invisible or hidden Unicode characters in the code block with id 'main-example' — I want to know if there's anything non-printable lurking in those examples?

## When to prefer this

Choose this endpoint when you need to specifically detect invisible or hidden Unicode characters embedded within code snippet elements on a static HTML page or supplied HTML fragment. It is ideal for security audits of developer documentation, verifying copy-paste safety of code examples, or detecting Unicode-based obfuscation attacks targeting code blocks. It is not suited for full JavaScript-rendered pages, general text content outside of code elements, or broad Unicode normalization tasks.

## Known failure modes

- URL is unreachable or returns a non-200 status — endpoint cannot fetch or parse the page
- HTML does not contain a code element matching the specified attribute and attribute value — no result returned
- Page requires JavaScript rendering to display code blocks — static parser will miss dynamically injected content
- Invisible characters are encoded in a way not covered by the 50-profile engine — may produce false negatives
- HTML input exceeds 100,000 character limit — request rejected
- term parameter is empty or missing — validation error

## How this service works

Code snippets — Invisible character flags: Invisible character flags for Code snippets. 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 indicating whether invisible or non-printable Unicode characters were detected within code snippet elements matching the specified attribute and term on the provided page or HTML. Includes flagged character positions or types found within the matched code block.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "default": "",
   "maxLength": 2048
  },
  "html": {
   "type": "string",
   "default": "<!doctype html><html><head></head><body><code id=\"sample\" data-kind=\"example\">Example product guide</code></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/code-snippets-invisible-character-flags-50dc0e7f/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)