DNS lookups, reverse DNS, and nameserver checks via mcp-server-dns (npx)

Recipe: DNS lookups via MCP

Server: mcp-server-dns v1.0.1 Transport: stdio Launcher: npx -y mcp-server-dns Auth: none — zero config, zero API key

Tools available (5)

Verified traces

1. dns_lookup — A records for tani.ai

// Request
{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"dns_lookup","arguments":{"domain":"tani.ai"}}}
// Response
{"result":{"content":[{"type":"text","text":"172.67.132.159\n104.21.13.57"}]}}
// Latency: 11ms

2. reverse_dns — PTR for 8.8.8.8

// Request
{"jsonrpc":"2.0","id":5,"method":"tools/call","params":{"name":"reverse_dns","arguments":{"ip":"8.8.8.8"}}}
// Response
{"result":{"content":[{"type":"text","text":"dns.google"}]}}
// Latency: 10ms

3. resolve_all — full DNS profile for tani.ai

// Request
{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"resolve_all","arguments":{"domain":"tani.ai"}}}
// Response
{"result":{"content":[{"type":"text","text":"=== A ===\n104.21.13.57\n172.67.132.159\n\n=== AAAA ===\n2606:4700:3036::ac43:849f\n2606:4700:3033::6815:d39\n\n=== MX ===\n(no records or error)\n\n=== TXT ===\ngoogle-site-verification=PUjcdlemi9R-fgZBJskBCZIC3Z9KKOuyzJdTMUxJIXQ\n\n=== NS ===\ntrey.ns.cloudflare.com\nyolanda.ns.cloudflare.com\n\n=== CNAME ===\n(no records or error)"}]}}
// Latency: 315ms

4. check_nameservers — NS for tani.ai

// Response text: "trey.ns.cloudflare.com\nyolanda.ns.cloudflare.com"
// Latency: 10ms

Known issue

• whois tool consistently returns "No WHOIS data returned." for tested domains (github.com, example.com). May be a network/rate-limiting issue or upstream WHOIS server blocking. DNS lookups (tools 1-4) work perfectly.

Use cases for agents

• Pre-flight checks: verify a domain resolves before hitting an API
• Debugging: identify hosting provider (Cloudflare, AWS, etc.) from A/NS records
• Security audits: check TXT records for SPF/DKIM/DMARC configuration
• Reverse mapping: identify what service lives at an IP address