# Luhn Algorithm Validator

> Luhn Algorithm Validator is a paid API for AI agents from dt0ur.online, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-02).

Validates a numeric string (credit card number or IMEI) against the Luhn checksum algorithm to determine if it is structurally valid.

## Facts

- Endpoint: POST https://dt0ur.online/api/utility/luhn-check?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/luhn-algorithm-validator-0cfbcfe0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_09Lh0NlUay84DhAf-8Cyx

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-algorithm-validator-0cfbcfe0 -d '<json body>'
```

Example prompt: Can you check if the credit card number 4532 0151 1283 0366 passes the Luhn checksum — I need to know if it's structurally valid before I process anything.

## When to prefer this

Use this endpoint when you need a fast, cheap, offline-style structural check of a credit card or IMEI number before hitting a live payment network or carrier API. It is ideal for pre-validating user input in forms, filtering out obviously invalid numbers early in a pipeline, or verifying IMEI numbers during device registration workflows. Prefer this over full payment authorization when you only need to confirm the number is well-formed, not that it is active or funded.

## Known failure modes

- Non-numeric input or unsupported characters may cause a validation error
- Empty string or missing 'number' field returns an error response
- Extremely short or malformed strings may return invalid without a checksum computation
- Network timeout if the service is unavailable

## How this service works

Validates a credit card or IMEI number against the Luhn checksum algorithm.

## Output

Returns a pass/fail result indicating whether the provided numeric string satisfies the Luhn (mod-10) checksum algorithm, confirming the number is structurally valid (not necessarily active or real, just correctly formed).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "number": {
   "type": "string",
   "description": "Numeric string (spaces/dashes allowed)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/luhn-algorithm-validator-0cfbcfe0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from dt0ur.online](https://www.zero.xyz/host/dt0ur.online/llms.txt)