Other & General Hosted remote
Check Digit Validator
Validates IBAN/ISBN/EAN/Luhn checksums and finds the one wrong digit
Install
Remote streamable-http
https://check-digit.gumballtools.com/api/mcpClient config (Claude Desktop, Cursor, Windsurf and most MCP clients)
{
"mcpServers": {
"com-gumballtools-check-digit": {
"url": "https://check-digit.gumballtools.com/api/mcp"
}
}
}Source: official MCP Registry record · registry name com.gumballtools/check-digit · published 2026-09-05 · updated 2026-09-05. Not an endorsement; review the code before connecting it to anything sensitive.