# Validator Suite — ISBN, IBAN & Credit Card Validator

> Validator Suite — ISBN, IBAN & Credit Card Validator is a paid API for AI agents from agent402.tools, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-14).

Validates ISBN (book identifier), IBAN (bank account number), and credit card number (Luhn check) in a single bundled API call for one x402 payment.

## Facts

- Endpoint: POST https://agent402.tools/api/skill/validator-suite
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/validator-suite-isbn-iban-credit-card-validator-cd0b73e8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xnhT_91U-jYA8TO7nsnT2

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 validator-suite-isbn-iban-credit-card-validator-cd0b73e8 -d '<json body>'
```

Example prompt: Can you validate this IBAN — DE89370400440532013000 — and also check if credit card number 4242424242424242 passes the Luhn check, all in one call?

## When to prefer this

Use this endpoint when you need to validate two or more of these identifier types (ISBN, IBAN, credit card) in the same workflow and want to minimize API calls and payment overhead. It is ideal for onboarding flows, data quality pipelines, or checkout validation where multiple identifier types must be checked simultaneously. Prefer this over calling individual validators separately when cost efficiency and latency matter.

## Known failure modes

- Invalid IBAN format returns a specific validation error indicating which check failed
- Credit card number that fails Luhn check is flagged as invalid but not an API error
- Malformed input (non-string, missing fields) may return a 400 error
- Network timeout or x402 payment failure prevents any results from being returned
- Providing none of the expected fields may return empty or default validation responses

## How this service works

Bundled execution of the Validator suite workflow — Validate common identifiers in one call: ISBN (book), IBAN (bank account), and credit card number (Luhn check). One x402 payment runs 3 underlying tools (isbn-validate, iban-validate, card-valida...

## Output

Returns validation results for each submitted identifier: whether the IBAN is structurally valid (country code, check digits, BBAN format), whether the credit card number passes the Luhn algorithm, and (if ISBN provided) whether the ISBN checksum is valid. All three results returned in a single response from one x402 payment.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "iban": {
   "type": "string",
   "description": "IBAN to validate (e.g. DE89370400440532013000)"
  },
  "number": {
   "type": "string",
   "description": "Credit card number to validate (e.g. 4242424242424242)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "args": {
   "iban": "DE89370400440532013000",
   "number": "4242424242424242"
  },
  "pack": "validator-suite",
  "steps": [
   {
    "ok": true,
    "slug": "isbn-validate",
    "result": {}
   },
   {
    "ok": true,
    "slug": "iban-validate",
    "result": {}
   },
   {
    "ok": true,
    "slug": "card-validate",
    "result": {}
   }
  ],
  "summary": "3/3 steps succeeded"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/validator-suite-isbn-iban-credit-card-validator-cd0b73e8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)