Check Digit Validator for Windsurf

com.gumballtools/check-digit

Validates IBAN/ISBN/EAN/Luhn checksums and finds the one wrong digit

client:Windsurf transport:streamable-http tools:1

Install Check Digit Validator in Windsurf

~/.codeium/windsurf/mcp_config.json · windows: %USERPROFILE%\.codeium\windsurf\mcp_config.json

{
  "mcpServers": {
    "check-digit": {
      "serverUrl": "https://check-digit.gumballtools.com/api/mcp"
    }
  }
}

Global only — Windsurf has no per-project MCP config. Refresh Cascade after saving. Windsurf docs