DNSDumpster MCP Server

Instructions

Implementation Reference

• server.py:343-402 (handler)

  The main handler function for the 'get_mx_records' tool, registered via @mcp.tool() decorator. It fetches MX records for the given domain using DNSDumpsterClient, processes the results including IPs and ASN info, formats them into a readable string, and handles errors gracefully.

  @mcp.tool()
  async def get_mx_records(domain: str, ctx: Context) -> str:
      """Get MX (mail) records for a domain.
  
      Args:
          domain: The domain name to query (e.g., example.com)
          ctx: Request context
  
      Returns:
          Formatted string containing MX records
      """
      if not domain:
          return "Error: Domain is required"
  
      # Validate domain
      if not is_valid_domain(domain):
          return "Error: Invalid domain name format"
  
      try:
          api_key = os.environ.get("DNSDUMPSTER_API_KEY")
          if not api_key:
              return "Error: API key not configured. Set DNSDUMPSTER_API_KEY environment variable."
  
          client = DNSDumpsterClient(api_key)
  
          try:
              ctx.info(f"Querying MX records for {domain}")
              result = await client.get_dns_records(domain)
  
              if "mx" not in result or not result["mx"]:
                  return f"No MX records found for {domain}"
  
              output_lines = [f"MX Records for {domain}:"]
  
              for record in result["mx"]:
                  host = record.get("host", "")
                  priority = record.get("priority", "")
  
                  priority_str = f" (Priority: {priority})" if priority else ""
                  output_lines.append(f"\nHost: {host}{priority_str}")
  
                  for ip_info in record.get("ips", []):
                      ip = ip_info.get("ip", "")
                      country = ip_info.get("country", "Unknown")
                      asn = ip_info.get("asn", "")
                      asn_name = ip_info.get("asn_name", "")
  
                      output_lines.append(f"  IP: {ip}")
                      output_lines.append(f"  Country: {country}")
                      if asn:
                          output_lines.append(f"  ASN: {asn}")
                      if asn_name:
                          output_lines.append(f"  ASN Name: {asn_name}")
  
              return "\n".join(output_lines)
          finally:
              await client.close()
  
      except Exception as e:
          return f"Error: {str(e)}"