Skip to content
RDAP API logo

RDAP API MCP server

Which MCP servers are RDAP API's own, from the official registry and from asking its own domain, whether they answer, and what they offer. A program checked each of these, nobody copied them from a product page.

read 2026-10-21

← Back to RDAP API

Whose server it is
  • Registry nameio.rdapapi/rdapverified in the MCP registry

The registry name sits under rdapapi.io. The registry only lets a publisher use that namespace after proving control of the domain through DNS or HTTP.

When we asked itchecked 2026-10-21
  • Stateanswerschecked 2026-10-21
  • Tools7
  • Server calls itselfRDAP API
  • Server version1.3.0
  • Protocol version2025-06-18

On 2026-10-21 the server answered initialize and tools/list without a sign-in. First answer in 203 ms.

Should an agent connect itConnect it
  • Its tools do every use case we checked: look up registration dates and nameservers for domains; pull registrar contact data for a domain.

Once connected

  • For "look up registration dates and nameservers for domains", the likely first call is domain-lookup.
  • For "pull registrar contact data for a domain", the likely first call is domain-lookup.

Said by rules from the measurements above. The likely first call is a model's pick from the tool list; read its description before relying on it.

Measured dailydaily checks: 14, the first on 2026-10-21
  • INITE MCP score100 of 100answers 100 · does the job 100 · definitions 100 · context 100 · connects 100
  • What an agent can do with it2 of 2 use cases
  • Answered100% of days14 of 14 daily checks
  • Median first answer451 ms
  • Space in an agent's context≈ 1,007 tokensthe definitions of all its tools (7), which an agent carries on every turn
  • Tool definitionsA · 100 of 100
  • Typed results0 of 7 toolsdeclared outputSchema: results come typed, read once
  • Every tool passes all six checks.

What an agent can do with it

  • can do · look up registration dates and nameservers for domains
  • can do · pull registrar contact data for a domain
  • not sure · add registration fields to a domain dataset in bulk

Each of the product's use cases, put to Jev against this server's tool list: can an agent do it with these tools?

Worth a look

None of the five warning signs in these definitions.

A program checks the server once a day: initialize and tools/list, no model. Tokens are the definitions' length at about four characters a token. The grade averages six checks of every tool's name, description, schema and annotations; it says how well the tools are described, not whether they work. The score weighs what was measured and nothing else: answering (25%), doing the product's job (25%), definitions (20%), context (10%), use (10%) and how readily a client connects (10%). A part that was not measured is left out, and a hidden instruction caps the score at 40. The state of vendors' MCP servers: method and numbers →

Tools it offers7 tools · read 2026-10-21
  • domain-lookup

    Look up normalized RDAP registration data (registrar, status, dates, nameservers, contacts) for a domain name.

  • bulk-domain-lookup

    Look up normalized RDAP registration data for several domain names in one pooled call. Requires a Pro or Business plan; every domain in the batch counts against the quota.

  • ip-lookup

    Look up normalized RDAP allocation data (network range, holder, country, status, geofeed URL) for an IP address or CIDR block.

  • asn-lookup

    Look up normalized RDAP data (holder, country, status, registration dates) for an autonomous system number.

  • nameserver-lookup

    Look up normalized RDAP data (IP addresses, status, sponsoring registrar) for a nameserver hostname.

  • entity-lookup

    Look up normalized RDAP data for an RIR entity handle — an organization or contact identifier such as "GOGL" or "ORG-RIEN1-RIPE". Only ARIN, RIPE, APNIC, LACNIC and AFRINIC handles resolve; a domain's registrar or registrant comes from…

  • tlds

    List the TLDs this API can query, or describe one: which RDAP server answers for it, since when it has been supported, and how often that server fills each field. Metadata, so it never counts against the monthly quota.

How to connect

Add the server to your MCP client config. Claude Desktop, Cursor and most other clients read this shape:

{
  "mcpServers": {
    "rdap": {
      "type": "http",
      "url": "https://rdapapi.io/mcp/rdap"
    }
  }
}

Add it

Claude Code, in a terminal

claude mcp add --transport http rdapapi https://rdapapi.io/mcp/rdap

Add to CursorAdd to VS Code

claude.ai, ChatGPT and other clients: add https://rdapapi.io/mcp/rdap as a custom connector in the settings.

Each line is something a program found when it went looking: the registry entry, the server's own answer, a spec that parses. A missing line means we did not find it, not that it does not exist.