isfree.se Model Context Protocol (MCP) server

A quick experiment to bring the power of isfree.se to your favorite LLM AI assistant¹ using Model Context Protocol (MCP)

SSE endpoint URL of the MCP server: https://mcp-server.isfree.se/sse

¹ MCP is now supported by all major AI assistants, including Claude, ChatGPT, and Gemini — but easy setup is still mostly limited to paid/power-user tiers. See instructions below.

Common questions

What is isfree.se?

isfree.se is a service built for fun by Kristofer Palmvik to make it easy to check if a Swedish .SE-domain is available to register.

Just type isfree.se/example in your browser to check if example.se is free or not (spoiler: it is not).

What is Model Context Protocol (MCP)?

Model Context Protocol (MCP) is an open standard that allows AI assistants, like Claude, to connect with external tools and services in real-time.

Think of it as a "USB-C for AI" – a universal way for language models to extend their capabilities beyond their built-in knowledge.

With MCP, your favorite AI assistant can check real-time information, interact with web services, and perform actions like checking domain availability without leaving your conversation.

What is the isfree.se MCP server?

This is a quick proof-of-concept implementation of an isfree-se MCP server, offering a checkSeDomain tool:

checkSeDomain

Checks if a Swedish (.se) domain is available for registration. The domain should include .se at the end.

From server: isfree-se

It makes it possible for an AI assistant that supports MCP to reach out and check the availability of a .SE-domain. This is typically not something an AI assistant is able to do.

What can it do?

The checkSeDomain tool accepts one of the following inputs:

Validation rejects non-.se inputs and requests that exactly one of domain or domains is provided.

Single lookups return one status; batch lookups return per-domain statuses.

Possible status values are

If one lookup fails, only that domain is marked as ERROR while other domains still return their own statuses.

Internationalized domains, such as räksmörgås.se, are supported and normalized before lookup.

The isfree.se MCP server is built using Cloudflare Workers.

Example of using isfree.se MCP server in Claude Desktop

How can I try it myself?

The isfree.se MCP server works with most major AI assistants. Setup varies by client:

Claude (claude.ai, Pro/Max/Enterprise)

Go to Settings → Integrations and paste in the server URL. No config files needed.

Claude Desktop

Add this to your config file (claude_desktop_config.json):

{
  "mcpServers": {
    "isfree-se": {
      "command": "npx",
      "args": ["mcp-remote", "https://mcp-server.isfree.se/sse"]
    }
  }
}

Requires Node.js installed.

ChatGPT (Pro/Team/Enterprise)

Enable Developer Mode under Settings → Advanced, then add the server URL via Edit MCP Config.

Cursor / Windsurf

Supported natively. Add the server in the MCP section of Settings, or use the same config format as Claude Desktop above.

VS Code with GitHub Copilot

Supported natively since VS Code 1.99. Add the server via the MCP settings in the Copilot Chat panel.

Gemini CLI

Supported natively via config file. See the Gemini CLI MCP docs.

Why is this so complicated to configure?

Setting up MCP, especially with remote servers, is still a somewhat manual process. That said, it has improved: Claude's web interface now lets you connect a remote server by simply pasting a URL, with no config files or Node.js required.

For other clients, you still need to edit a config file or navigate developer settings. Discovery is improving too — directories like MCP.so let you browse thousands of available servers. But it's not yet as seamless as installing a browser extension.

As MCP matures, the experience is expected to keep improving — particularly for non-technical users.

Is this really useful?

Not very, but maybe a little.

It is more of an experiment and prototype to learn more about MCP.

However, if you use Claude to come up with a new company name for your dog skateboard startup it might be very useful to be able to check the domain name availability. 😎

Is mcp-server.se still available?

Use isfree.se to check if the domain mcp-server.se is free.

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