# Foundry Credit Card Number Validator

> Foundry Credit Card Number Validator is a paid API for AI agents from minty-sprout.onrender.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-11-01).

Validates a credit card number via Luhn checksum algorithm and identifies the card brand (Visa, Mastercard, Amex, etc.) — format check only, data never stored.

## Facts

- Endpoint: POST https://minty-sprout.onrender.com/v1/card-validate?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/foundry-credit-card-number-validator-1d20e003
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pDyzSWjGN6a0Cwb9cMAu1

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 foundry-credit-card-number-validator-1d20e003 -d '<json body>'
```

Example prompt: Can you check if the card number 4242424242424242 is valid — specifically whether it passes the Luhn checksum and what brand it is?

## When to prefer this

Use this endpoint when you need a fast, stateless, privacy-safe format check on a credit card number — especially when you want both Luhn validation and brand detection in a single call without storing any card data. Prefer this over manual Luhn implementations when brand identification (Visa vs Mastercard vs Amex) is also needed. Not suitable for actual payment authorization or real-time card verification with issuers.

## Known failure modes

- Card number too short or too long (outside 12–19 digits) — likely a 400 error or validation failure
- Non-numeric characters in input causing a parse error
- Unknown or unrecognized card brand returns null/unknown brand field
- Luhn check fails for syntactically valid-length numbers — returns valid_luhn: false
- Service unavailable on Render cold start — potential timeout or 503

## How this service works

Credit card number validator: Luhn checksum and card brand (Visa, Mastercard, Amex...). Format check only, never stored. Input: a card number.

## Output

Returns a JSON object indicating whether the card number passes the Luhn checksum (valid_luhn: boolean), the detected card brand (e.g. Visa, Mastercard, Amex), the card number length, and a masked version of the number (e.g. '424242******4242'). Also includes a note confirming the number is never stored or charged.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "input": {
   "type": "string",
   "maxLength": 8000,
   "description": "A card number (12 to 19 digits)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "note": "Format check only; never stored or charged.",
  "brand": "Visa",
  "length": 16,
  "masked": "424242******4242",
  "valid_luhn": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/foundry-credit-card-number-validator-1d20e003/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from minty-sprout.onrender.com](https://www.zero.xyz/host/minty-sprout.onrender.com/llms.txt)