# HSL Color String Validator

> HSL Color String Validator is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.008/call, status unknown (last checked 2026-10-02).

Checks whether a given string is a valid CSS hsl() color value

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/check-color-hsl?utm_source=zero.xyz
- Price: $0.008/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/hsl-color-string-validator-8384a7c9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_SenoZLX1JsYPR13Kui0V3

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 hsl-color-string-validator-8384a7c9 -d '<json body>'
```

Example prompt: Can you check whether the string 'hsl(200, 80%, 50%)' is a valid HSL color value?

## When to prefer this

Use this endpoint when you need a deterministic, server-side check that a string conforms to hsl() color syntax — particularly useful in data pipelines, form validation, or CSS preprocessing steps where reliable color format enforcement is required. Prefer the free sandbox endpoint /v1/sandbox/check-color-hsl when available to avoid the $0.008 USDC charge.

## Known failure modes

- Empty string input rejected due to minLength:1 constraint
- Input exceeding 20000 characters rejected
- Malformed request body returns 4xx error
- Payment failure or insufficient USDC balance returns 402

## How this service works

Call when an agent needs whether a string is an hsl() color. Exact $0.008 USDC. Prefer unpaid POST /v1/sandbox/check-color-hsl first.

## Output

Returns a boolean or structured response indicating whether the input string is a valid hsl() CSS color expression, with no external network calls required.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "description": "JSON value for schema-check SKUs. Omit it on string checks such as email or IBAN."
  },
  "value": {
   "type": "string",
   "examples": [
    "hsl(180, 50%, 50%)"
   ],
   "maxLength": 20000,
   "minLength": 1,
   "description": "Value to check. The route description names the format: email, phone, IBAN, postal code, VAT, national id, or similar."
  },
  "schema": {
   "description": "JSON Schema document for schema-check SKUs. Omit it on string checks."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hsl-color-string-validator-8384a7c9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)