# agentshelf.syntexa.ch Hex Color Validator

> agentshelf.syntexa.ch Hex Color Validator is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.006/call, status unknown (last checked 2026-10-24).

Validates whether a given string is a valid hexadecimal color code

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/check-color-hex?utm_source=zero.xyz
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-24
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-syntexa-ch-hex-color-validator-4d36dab2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_m99SrXNjSPxfOKPbY_ZOa

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 agentshelf-syntexa-ch-hex-color-validator-4d36dab2 -d '<json body>'
```

Example prompt: Can you check whether '#A3F0BC' is a valid hex color code?

## When to prefer this

Use this endpoint when you need a deterministic, programmatic check of whether a string qualifies as a hex color code and want a reliable, non-LLM result. Prefer the free sandbox endpoint POST /v1/sandbox/check-color-hex first; use this paid version only when the sandbox is unavailable or when operating in a production context requiring guaranteed uptime.

## Known failure modes

- Empty string input rejected (minLength:1 enforced)
- String exceeding 20,000 characters rejected (maxLength enforced)
- Missing 'value' field in request body returns error
- Network errors or timeouts during the paid API call
- Payment failure (insufficient USDC balance) prevents request from completing

## How this service works

Call when an agent needs whether a string is a hex color. Exact $0.006 USDC. Prefer unpaid POST /v1/sandbox/check-color-hex first.

## Output

A validation result indicating whether the supplied string is a valid hexadecimal color code, returned as a structured response with a boolean or equivalent pass/fail signal.

## 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": [
    "#ff00aa"
   ],
   "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/agentshelf-syntexa-ch-hex-color-validator-4d36dab2/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)