x402 Format Checker
IBAN, EU VAT, NIP, REGON, PESEL, email checks. Only $0.001 (0.1 cent) per check via x402 on Base
Should I use this
Quality & Safety
Based on automated analysis of tool definitions and protocol compliance.
Context Cost
This is the approximate number of tokens consumed each time the server's tools are loaded into a model's context. Higher counts reduce the attention available for other tasks.
Install
One-Click Install
Add this to your `claude_desktop_config.json` file:
{
"mcpServers": {
"format-checker": {
"url": "https://x402-test.crewofthecaptain.com/mcp"
}
}
}Remote endpoints
https://x402-test.crewofthecaptain.com/mcpstreamable-httphttps://validate.crewofthecaptain.com/mcpstreamable-httpWhat it can do
Tool inventory
Tools (7)
🟢list_types
List the available checks, price, network and payment details (free). Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base.
Input Schema
{
"type": "object",
"properties": {},
"$schema": "https://json-schema.org/draft/2020-12/schema"
}🟢validate_iban(value)
IBAN: country length + ISO 13616 mod-97 checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Input Schema
{
"type": "object",
"properties": {
"value": {
"type": "string",
"minLength": 1,
"maxLength": 512,
"description": "String to check, e.g. PL61109010140000071219812874"
}
},
"required": [
"value"
],
"$schema": "https://json-schema.org/draft/2020-12/schema"
}🟢validate_eu_vat(value)
EU VAT number: per-country format (offline, no VIES); PL also NIP checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Input Schema
{
"type": "object",
"properties": {
"value": {
"type": "string",
"minLength": 1,
"maxLength": 512,
"description": "String to check, e.g. PL5260250274"
}
},
"required": [
"value"
],
"$schema": "https://json-schema.org/draft/2020-12/schema"
}🟢validate_pl_nip(value)
Polish NIP tax id: 10 digits + weighted mod-11 checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Input Schema
{
"type": "object",
"properties": {
"value": {
"type": "string",
"minLength": 1,
"maxLength": 512,
"description": "String to check, e.g. 5260250274"
}
},
"required": [
"value"
],
"$schema": "https://json-schema.org/draft/2020-12/schema"
}🟢validate_pl_regon(value)
Polish REGON: 9 or 14 digits + mod-11 checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Input Schema
{
"type": "object",
"properties": {
"value": {
"type": "string",
"minLength": 1,
"maxLength": 512,
"description": "String to check, e.g. 123456785"
}
},
"required": [
"value"
],
"$schema": "https://json-schema.org/draft/2020-12/schema"
}🟢validate_pl_pesel(value)
Polish PESEL: checksum + encoded birth date and sex. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Input Schema
{
"type": "object",
"properties": {
"value": {
"type": "string",
"minLength": 1,
"maxLength": 512,
"description": "String to check, e.g. 44051401359"
}
},
"required": [
"value"
],
"$schema": "https://json-schema.org/draft/2020-12/schema"
}🟢validate_email(value)
Email address syntax (dot-atom local part, LDH domain; no DNS). Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Returns {type, valid, normalized, reason}; the input is never echoed or stored and personal identifiers are masked.
Input Schema
{
"type": "object",
"properties": {
"value": {
"type": "string",
"minLength": 1,
"maxLength": 512,
"description": "String to check, e.g. [email protected]"
}
},
"required": [
"value"
],
"$schema": "https://json-schema.org/draft/2020-12/schema"
}Community
Evidence