[md]DNS MCP server

modules/example-dns-mcp · HTTP + SSE · Scala.js (Node.js) · port 8053

A Scala.js server running on Node.js, demonstrating how to wrap Node.js callback-based APIs (dns module) into cats-effect IO via IO.async_. Uses the HTTP transport, which allows concurrent requests — a good fit for the async nature of Node.js.

• Tools: resolve_dns (A, AAAA, MX, TXT, CNAME, NS records), reverse_dns (IP to hostnames)
• Resource: dns://reference/record-types (static markdown reference)
• Prompt: diagnose_dns — comprehensive DNS diagnosis for a domain

Build and run

# Link the Scala.js output
sbt exampleDns/fastLinkJS

# Run on Node.js
node modules/example-dns-mcp/target/scala-3.3.4/example-dns-mcp-fastopt/main.js
# Server starts on http://0.0.0.0:8053

Configure in Claude Code

.mcp.json:

{
  "mcpServers": {
    "dns": {
      "type": "streamable-http",
      "url": "http://localhost:8053/mcp"
    }
  }
}