x402 Format Checker

–Likes are community signals, not a measured score.

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

IBAN, EU VAT, NIP, REGON, PESEL, email checks. Only $0.001 (0.1 cent) per check via x402 on Base

Author	com.crewofthecaptain
Access	remote
Publisher key required	No
Measured state	Deep-tested
L1 liveness	alive
L1 latency	2129 ms
Last measured	2026-10-26

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "x402 Format Checker": {
      "url": "https://validate.crewofthecaptain.com/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (7)

list_types read-only
List the available checks, price, network and payment details (free). Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base.
Hints: read-only yes · destructive not declared · idempotent not declared · open-world no
validate_iban read-only
IBAN: country length + ISO 13616 mod-97 checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Parameters:
- value (required) — string — String to check, e.g. PL61109010140000071219812874
Hints: read-only yes · destructive not declared · idempotent yes · open-world no
validate_eu_vat read-only
EU VAT number: per-country format (offline, no VIES); PL also NIP checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Parameters:
- value (required) — string — String to check, e.g. PL5260250274
Hints: read-only yes · destructive not declared · idempotent yes · open-world no
validate_pl_nip read-only
Polish NIP tax id: 10 digits + weighted mod-11 checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Parameters:
- value (required) — string — String to check, e.g. 5260250274
Hints: read-only yes · destructive not declared · idempotent yes · open-world no
validate_pl_regon read-only
Polish REGON: 9 or 14 digits + mod-11 checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Parameters:
- value (required) — string — String to check, e.g. 123456785
Hints: read-only yes · destructive not declared · idempotent yes · open-world no
validate_pl_pesel read-only
Polish PESEL: checksum + encoded birth date and sex. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Parameters:
- value (required) — string — String to check, e.g. 44051401359
Hints: read-only yes · destructive not declared · idempotent yes · open-world no
validate_email read-only
Email address syntax (dot-atom local part, LDH domain; no DNS). Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Parameters:
- value (required) — string — String to check, e.g. [email protected]
Hints: read-only yes · destructive not declared · idempotent yes · open-world no

Publisher website

Measured by MCPYP probing. Untested fields are omitted, never estimated. Listing is always free; MCPYP never proxies calls or stores user tokens.