Check Digit Validator for Grok

Install Check Digit Validator in Grok

.mcp.json (in your project root)

{
  "mcpServers": {
    "check-digit": {
      "type": "http",
      "url": "https://check-digit.gumballtools.com/api/mcp"
    }
  }
}

Grok Build reads Claude Code's .mcp.json and Claude Desktop's config unchanged, so a server you have already set up there needs nothing new. The Grok web app and X integration do not take custom servers. Grok docs