CheckDigit
Offline check-digit validation for IBAN, BIC, EU VAT, GTIN/EAN/UPC and ISBN. Format check only.
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": {
"checkdigit": {
"url": "https://checkdigit.mike-tusa.workers.dev/mcp"
}
}
}Remote endpoints
https://checkdigit.mike-tusa.workers.dev/mcpstreamable-httpWhat it can do
Tool inventory
Tools (2)
🟢validate_code(code, type)
Check the format and check digits of one identifier: IBAN (ISO 13616, per-country length and layout), BIC/SWIFT (ISO 9362 format and country), EU VAT number (offline checksum, VIES not queried), GTIN/EAN-8/UPC-A/EAN-13/GTIN-14 (GS1 mod 10) or ISBN-10/13. type "auto" (default) detects the type from the shape. Returns valid, a reason when invalid (e.g. the expected check digit), and normalized/formatted forms. Format check, not a compliance check: valid does not mean the account, registration or product exists. The code is sent in a POST body and not stored or logged. Read-only. Same engine, keys and limits as POST /v1/{type}.
Input Schema
{
"type": "object",
"properties": {
"code": {
"type": "string",
"description": "The identifier to check, e.g. \"DE89 3704 0044 0532 0130 00\", \"ATU13585627\", \"4006381333931\" or \"978-0-306-40615-7\". Spaces, hyphens and dots are ignored. Max 64 characters.",
"minLength": 1,
"maxLength": 64
},
"type": {
"type": "string",
"description": "auto (default), iban, bic, vat, gtin or isbn.",
"enum": [
"auto",
"iban",
"bic",
"vat",
"gtin",
"isbn"
],
"maxLength": 6
}
},
"required": [
"code"
],
"additionalProperties": false
}Output Schema
{
"type": "object",
"properties": {
"type": {
"type": "string"
},
"input": {
"type": "string"
},
"normalized": {
"type": "string"
},
"valid": {
"type": "boolean"
},
"reason": {
"type": "string"
},
"country": {
"type": "string"
},
"country_name": {
"type": "string"
},
"formatted": {
"type": "string"
},
"check_digits": {
"type": "string"
},
"check_digit": {
"type": "string"
},
"expected_check_digit": {
"type": "string"
},
"format": {
"type": "string"
},
"bban": {
"type": "string"
},
"bank_code": {
"type": "string"
},
"sepa": {
"type": "boolean"
},
"number": {
"type": "string"
},
"checksum": {
"type": "string"
},
"vies_checked": {
"type": "boolean"
},
"ean13": {
"type": "string"
},
"isbn10": {
"type": "string"
},
"isbn13": {
"type": "string"
},
"detected_as": {
"type": "string"
},
"candidates": {
"type": "array",
"items": {
"type": "string"
}
}
},
"required": [
"input",
"valid"
]
}🟢get_meta
Return the service version and build, supported IBAN and VAT countries, GTIN formats, the disclaimer and the current limits. Does not count as a check. Read-only. Same data as GET /v1/meta.
Input Schema
{
"type": "object",
"properties": {},
"additionalProperties": false
}Output Schema
{
"type": "object",
"properties": {
"service": {
"type": "string"
},
"version": {
"type": "string"
},
"build": {
"type": "string"
},
"disclaimer": {
"type": "string"
},
"endpoints": {
"type": "array",
"items": {
"type": "string"
}
},
"iban": {
"type": "object"
},
"vat": {
"type": "object"
},
"gtin": {
"type": "object"
},
"bic": {
"type": "object"
},
"limits": {
"type": "object"
},
"privacy": {
"type": "string"
}
},
"required": [
"service",
"version"
]
}Community
Evidence