# Polish PESEL Validator

> Polish PESEL Validator is a paid API for AI agents from validate.crewofthecaptain.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-12).

Validates the format and checksum of a Polish PESEL national identification number, returning validity status and normalized form.

## Facts

- Endpoint: POST https://validate.crewofthecaptain.com/api/validate/pl-pesel?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polish-pesel-validator-e7e6554a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FmvAPsD8Uz1KLXC7opOC8

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 polish-pesel-validator-e7e6554a -d '<json body>'
```

Example prompt: Can you check whether this Polish PESEL number is valid: 44051401458?

## When to prefer this

Choose this endpoint when you specifically need to validate Polish PESEL numbers — the 11-digit national personal identification number used in Poland. It is purpose-built for PESEL checksum logic, which differs from generic regex checks. Prefer it over a general-purpose validator when dealing with Polish user identity data, KYC flows, or compliance checks requiring authoritative PESEL validation. It costs only $0.001 per call via x402/USDC on Base, making it economical for high-volume pipelines.

## Known failure modes

- Invalid or missing 'value' field returns valid:false with a reason describing the format error
- Non-string or empty input may return a 400-level error
- PESEL with wrong checksum digit returns valid:false with reason explaining checksum failure
- Payment failure via x402 returns HTTP 402 before validation occurs

## How this service works

Format and checksum validation for IBAN, EU VAT, Polish NIP/REGON/PESEL and email, pay-per-call via x402. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base.

## Output

A JSON object containing: 'type' (pl-pesel), 'valid' (boolean indicating whether the PESEL passes format and checksum checks), 'reason' (human-readable explanation such as 'ok' or a description of the error), and 'normalized' (the cleaned, canonical form of the PESEL string).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "value": {
   "type": "string",
   "maxLength": 512
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "type": "pl-pesel",
  "valid": true,
  "reason": "ok",
  "normalized": "…"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polish-pesel-validator-e7e6554a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from validate.crewofthecaptain.com](https://www.zero.xyz/host/validate.crewofthecaptain.com/llms.txt)