For AI assistants

MCP

Every dns-doctor.com check as a tool for AI assistants, via the Model Context Protocol. If you prefer plain HTTP instead, see the REST API.

Overview

POST/mcp

The MCP server (Model Context Protocol) exposes every dns-doctor check as a tool for AI assistants like Claude, over Streamable HTTP at https://dns-doctor.com/mcp. It is stateless (JSON-RPC 2.0, no session state): each POST request is independent. Free, and the same engine as the REST API.

Connect in Claude

Easiest with Claude Code, a single command:

Claude Code

claude mcp add --transport http dns-doctor https://dns-doctor.com/mcp

For higher rate limits with your regfish API token (replace #api-token#):

Claude Code, with token

claude mcp add --transport http dns-doctor https://dns-doctor.com/mcp \
  --header "Authorization: Bearer #api-token#"

Or as a Claude Code plugin (also adds the /dns-check and /mail-check commands):

Plugin

claude plugin marketplace add regfish/claude-plugin
claude plugin install dns-doctor@regfish

Plugin repo on GitHub ↗

In the Claude desktop app or on claude.ai, add it as a custom connector with this URL instead (no CLI):

https://dns-doctor.com/mcp

The tools are then available. Test it manually without a client (list tools, then call a check):

Example

curl -X POST https://dns-doctor.com/mcp \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

Example

curl -X POST https://dns-doctor.com/mcp \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"dns_health_check","arguments":{"domain":"example.com"}}}'

Tools

Tool	Description
dns_health_check	Full health check: 25+ tests with score, findings and copy-ready fixes.
dns_lookup	Raw DNS records over DoH: A, AAAA, MX, TXT, NS, SOA, CAA, DS, DNSKEY, SRV, CNAME, PTR.
dns_propagation	Authoritative nameservers directly plus 5 public resolvers with a consistency verdict.
domain_availability	Domain availability via RDAP (TLDs without RDAP return state "unknown").
dkim_check	Inspect a DKIM key for a domain and selector: type, key length, status.
dnssec_check	DS and DNSKEY chain: unsigned, valid or broken.
mail_check	MX, forward and reverse DNS (FCrDNS) and TCP port availability of the mail servers.
seo_check	Visibility on Google and AI assistants: indexing, content, technical basics, llms.txt.
idn_convert	IDN and punycode conversion both ways (no rate limit).
generate_record	Build DNS records: spf, dmarc, caa or mta-sts, with structured warnings.

Auth & rate limits

Same auth and rate limits as the REST API: anonymous per IP and day, much higher with an existing regfish API key (Bearer or X-Api-Key, identical for api.regfish.de and api.regfish.com). The key is verified server-side by introspection; dns-doctor does not store it.

Example

curl -X POST https://dns-doctor.com/mcp \
  -H 'Authorization: Bearer <regfish-token>' \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"dns_lookup","arguments":{"name":"regfish.de","type":"MX"}}}'