# AgentShelf Spanish IBAN Validator

> AgentShelf Spanish IBAN Validator is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-02).

Validates whether a given IBAN is a mod-97-valid Spanish (ES) IBAN of exactly 24 characters

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/check-iban-es?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-spanish-iban-validator-9769b6cf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0-XQ4aBMt5ORa2vkz6GAi

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 agentshelf-spanish-iban-validator-9769b6cf -d '<json body>'
```

Example prompt: Can you check whether ES9121000418450200051332 is a valid Spanish IBAN — specifically that it's 24 characters long and passes the mod-97 check?

## When to prefer this

Use this endpoint when you need a deterministic, algorithmic check that an IBAN is structurally valid for Spain (ES prefix, 24-character length, mod-97 checksum) without any network lookups or LLM inference. Ideal before initiating payments or onboarding Spanish bank accounts. Try the free sandbox endpoint POST /v1/sandbox/check-iban-es first; fall back to this paid endpoint when the sandbox is unavailable or when production verification is required.

## Known failure modes

- IBAN not 24 characters — returns invalid or length error
- IBAN does not start with ES country code — returns invalid
- Mod-97 checksum fails — returns invalid with checksum error
- Empty or missing value field — returns bad request
- Value exceeds maxLength 20000 — returns error
- Network or service unavailability — returns 5xx error

## How this service works

Call when an agent needs whether an IBAN is a mod-97-valid ES number of length 24. Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/check-iban-es first.

## Output

Returns a boolean or structured result indicating whether the provided IBAN is a valid Spanish (ES) IBAN: exactly 24 characters long, starts with 'ES', and passes the mod-97 checksum algorithm.

## 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": [
    "ES73AAAA0000000000000000"
   ],
   "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/agentshelf-spanish-iban-validator-9769b6cf/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)