# x402 Format Checker

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

- name: com.crewofthecaptain/format-checker
- version: 1.3.0
- connection class: R0 (autonomous)
- trust: 83/100 flags: no-repository
- quality: 89/100 (good)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/com.crewofthecaptain%2Fformat-checker
- tools: https://api.protogrid.dev/v1/servers/com.crewofthecaptain%2Fformat-checker/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "format-checker": {
      "type": "http",
      "url": "https://validate.crewofthecaptain.com/mcp"
    }
  }
}
```


## Trust

- hygiene: 80
- liveness: 100
- freshness: 100
- provenance: 55
- drivers: +dns-namespace +website +reachable +uptime-100% +updated-9d-ago -no-repository
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 89/100 (good)

### protocol: 88 (weight 25)

- pass `protocol.modern`: supports 2026-07-28 (server/discover)
- pass `protocol.stateless`: answers without a session
- pass `protocol.transport`: streamable HTTP
- warn `protocol.list_ttl`: tools/list declares ttlMs 0, so clients re-fetch it on every use

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 86 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- pass `tools.annotations`: 7 of 7 tools declare readOnlyHint or destructiveHint
- fail `tools.directory_hints`: no tool declares all four of readOnlyHint, destructiveHint, idempotentHint and openWorldHint; missing: list_types (destructiveHint, idempotentHint); validate_eu_vat (destructiveHint); validate_email (destructiveHint); …
- pass `tools.token_cost`: about 879 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: 100 (weight 15)

- pass `stability.changes`: no tool changes in 30 days
- pass `stability.rug_pull`: no tool changed its meaning under the same name

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 7, about 879 tokens to load them all
- tool set hash: 24ac4654b7cf46813050c84f6e5fb332
- badge: [![protogrid quality](https://protogrid.dev/badge/com.crewofthecaptain/format-checker.svg)](https://protogrid.dev/servers/com.crewofthecaptain/format-checker)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

_No tool definition changes recorded._

## Remotes

- https://validate.crewofthecaptain.com/mcp (streamable-http, auth none, reachable true, uptime30d 1)

## Packages

_none_

## Tools (7)

- `list_types`: 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.
- `validate_email`: 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.
- `validate_eu_vat`: 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.
- `validate_iban`: 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.
- `validate_pl_nip`: 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.
- `validate_pl_pesel`: 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.
- `validate_pl_regon`: 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.