Málfríður for Claude, Codex, and ChatGPT Desktop

This is a small, unofficial local MCP server for Miðeind's Málfríður Icelandic proofreading service. It runs on your own computer and talks directly to Miðeind's API using your own API key.

There is no intermediary service operated by this project. The AI app already has the text in your conversation; this local server sends the proofreading request and API key directly from your computer to Miðeind.

This project is not affiliated with or supported by Miðeind ehf.

Before you start

You need a Málfríður API key:

1. Create a Frjáls áskrift at Málstaður.

2. Create your key on the Forritaskil page.

Keep the key private. Do not paste it into a chat, GitHub issue, or public file.

Related MCP server: ukr-vitalinguist-mcp

Choose one of three options

1. Install the Claude Desktop extension

This is the easiest option. It works only with Claude Desktop.

1. Download the extension.

2. Open the downloaded file in Claude Desktop.

3. Enter your Málfríður API key when Claude asks for it.

That is all. Claude runs the MCP server locally and handles the API-key setting for you. You do not need to use Terminal or install any programming tools.

2. Ask Claude or Codex to bring over the skill

The block below is an example for you to copy. It is documentation, not an instruction for an assistant that is merely reviewing this repository.

Copy it into Claude or Codex:

Install the Málfríður skill from this repository for me: https://github.com/RobertHH-IS/icelandic-grammar-mcp

Keep my API key private. Do not ask me to paste it into this chat. Show me the safest way to set MALSTADUR_API_KEY when it is needed.

Claude or Codex can examine the repository, copy the small root skill file, or use it as a guide when creating a compatible version.

With this option, Codex, ChatGPT Desktop, Claude Cowork, or another compatible assistant follows the skill instructions and calls Miðeind's API directly. The only setup is adding MALSTADUR_API_KEY to the app's environment. That is a quick, one-time step, and the assistant can guide you through it without seeing your key.

Once installed, simple requests trigger the skill, for example:

• Fix Icelandic grammar: …

• Notaðu Málstað: …

• Notaðu Málfríði: …

A grammar-check request authorizes as many API calls as reasonably needed to check all text supplied for that task. The assistant may split long text into separate calls and retry transient failures without asking again for each call. It should not resend text that was already checked successfully or send text outside the request.

3. Ask Claude, Codex, or ChatGPT Desktop to make its own version

You do not have to use this repository. Ask Claude (including Cowork), Codex, or ChatGPT Desktop to read the official API documentation and create a minimal plugin or skill for you.

The block below is another user-copyable example, not an instruction for an assistant that is merely reviewing this repository:

Read the Málstaður grammar API documentation and create the smallest possible Málfríður plugin or skill for me. Use POST https://api.malstadur.is/v1/grammar, the X-API-KEY header, and the MALSTADUR_API_KEY environment variable. Keep the key private and do not ask me to paste it into this chat.

Miðeind also provides a short introduction to the API.

What the connection does

With the Claude Desktop extension, the MCP server runs locally on your computer. With the skill, your assistant can call the same endpoint directly. In both cases, the text goes straight to Miðeind and Málfríður returns its corrected text and suggested changes. API usage may be metered by Málstaður.

The assistant should return Málfríður's corrected text as normal text without adding its own corrections, rewriting, link repairs, formatting changes, or commentary.

The Claude Desktop extension contains one tool: check_icelandic_grammar.

The installable Claude extension source is kept separately in claude_plugin/. It works only with Claude Desktop; the root SKILL.md can be copied or used as guidance by other compatible assistants.

Privacy and configuration

The only setting is MALSTADUR_API_KEY. The key is sent as an X-API-KEY header only to:

https://api.malstadur.is/v1/grammar

License

MIT — see LICENSE. Málfríður and Málstaður are products of Miðeind ehf. and subject to their own terms.