app.subdomain/subdomains

Official

Subdomain API

Find known subdomains of a domain. Passive data; may include historic entries. List or count.

Find known subdomains of a domain using passive reconnaissance data.

Install

claude_desktop_config.json

{
  "mcpServers": {
    "subdomains": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://api.subdomain.app/mcp"
      ]
    }
  }
}

Desktop config is stdio-only; this bridges via mcp-remote. Native remote: Settings > Connectors.