# JCB Card Luhn Validator

> JCB Card Luhn Validator is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Validates whether a card number passes the Luhn algorithm and matches the JCB card network format

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/check-card-jcb?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/jcb-card-luhn-validator-0bda5845
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3FXpOZ23tvNwqPj_IKTka

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 jcb-card-luhn-validator-0bda5845 -d '<json body>'
```

Example prompt: Check whether this card number is a valid JCB card — run the Luhn check and confirm it matches the JCB network: 3530111333300000

## When to prefer this

Use this endpoint when you need a lightweight, stateless check that a card number both passes the Luhn algorithm and belongs to the JCB card network specifically. Prefer the free sandbox endpoint POST /v1/sandbox/check-card-jcb for testing. Choose this over generic Luhn validators when JCB network identification is also required in a single call.

## Known failure modes

- Empty or missing value field returns an error
- Value exceeding 20000 characters or under 1 character is rejected by schema
- Non-numeric or malformed strings may return invalid/false result rather than an error
- Network timeout or 402 payment failure if USDC payment is not included

## How this service works

Call when an agent needs whether a number passes Luhn and matches jcb. Nothing is stored. Exact $0.001 USDC. Prefer unpaid POST /v1/sandbox/check-card-jcb first.

## Output

Returns a result indicating whether the provided card number passes the Luhn algorithm checksum and whether it matches the JCB card network's BIN/prefix pattern. Nothing is stored server-side.

## 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/jcb-card-luhn-validator-0bda5845/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)