# Luhn Credit Card Number Validator

> Luhn Credit Card Number Validator is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.006/call, status unknown (last checked 2026-10-02).

Validates whether a card-shaped number string passes the Luhn (mod-10) checksum algorithm

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/check-card-any?utm_source=zero.xyz
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/luhn-credit-card-number-validator-a25b55b3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NiymJtSUUQ3VbERtjd5tq

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 luhn-credit-card-number-validator-a25b55b3 -d '<json body>'
```

Example prompt: Can you check whether the card number 4111111111111111 passes the Luhn checksum — I just need to know if it's structurally valid before I pass it to our payment processor?

## When to prefer this

Choose this endpoint when you need a stateless, fast Luhn checksum check on a card-shaped number string without storing any data. Use the free sandbox endpoint POST /v1/sandbox/check-card-any first if available. Prefer this paid endpoint when the sandbox is unavailable or when operating in production. It does not validate that the card is active, issued, or belongs to a real account — only that the digits satisfy the mod-10 algorithm.

## Known failure modes

- Empty or missing value field returns an error
- Value exceeds 20000 character maxLength
- Non-numeric characters may cause unexpected results
- Payment failure if USDC balance is insufficient for the $0.006 charge
- Network timeout if the endpoint is temporarily unavailable

## How this service works

Call when an agent needs whether a card-shaped number passes Luhn. Nothing is stored. Exact $0.006 USDC. Prefer unpaid POST /v1/sandbox/check-card-any first.

## Output

A boolean or pass/fail indicator showing whether the submitted card number string satisfies the Luhn (mod-10) algorithm. No card data is stored. The result reflects only structural checksum validity, not whether the card is active or real.

## 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": [
    "411111"
   ],
   "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/luhn-credit-card-number-validator-a25b55b3/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)