Check Digit Validator for Zed

com.gumballtools/check-digit

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

client:Zed transport:streamable-http tools:1

Install Check Digit Validator in Zed

~/.config/zed/settings.json · windows: %APPDATA%\Zed\settings.json

{
  "context_servers": {
    "check-digit": {
      "url": "https://check-digit.gumballtools.com/api/mcp"
    }
  }
}

Merge this into your existing settings object — do not replace the file. Zed docs