Zefix MCP

> ⚠️ Unofficial MCP server for zefix.ch – Switzerland Central Business Name Index.

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This project is not affiliated with or endorsed by the Federal Department of Justice and Police (FDJP) - Federal Office of Justice (FOJ) who are developing and maintaining zefix.ch.

Features and Use-cases

• Allows your AI-assistant to search for companies incorporated in Switzerland by their name or UID (`CHE-nnn.nnn.nnn`) with optional filters by canton of incorporation, legal form, location, previous names, etc. (mimics all filters in Zefix GUI).
• Equips your AI-assistant with full company details available in Zefix (business names and identifiers, purpose, address, auditors, change history, capital, names of legal representatives, merges & acquisitions) to build further automation workflows or answer business-specific questions.

Sample questions MCP can answer

Company lookup

• *"Find if Google has a legal body in Switzerland and show me their registered address."*
• *"Was ist der vollständige rechtliche Name und die UID des Unternehmens, das als Migros bekannt ist?"*
• *"Recherche le CHE-169.865.482 et dis-moi tout ce que tu sais à son sujet."*

Filtering & discovery

• *"List all active Treuhand companies headquartered in canton Schaffhausen."*
• *"Finde Einzelunternehmen im Bereich Malerei, die irgendwo in der Grossregion Zürich eingetragen sind."*
• *"Dresse une liste des adresses et des représentants légaux de toutes les banques en Romandie."*

History & changes

• *"What is the new name of the company formerly known as 'SwissAir'?"*
• *"Zeig mir die vollständige Namens- und Eigentümergeschichte von Credit Suisse."*
• *"Y a-t-il des entreprises qui ont repris ou fusionné avec UBS AG ?"*

Due diligence & research

• *"Who is listed as auditor for Zurich Insurance Group?"*
• *"Ich stehe kurz vor der Unterzeichnung eines Vertrags mit Hans Müller als Vertreter von Lindt & Sprüngli – ist er dazu bevollmächtigt?"*
• *"Vérifie que Bollinger est une entreprise active spécialisée dans la plomberie, et dis-moi depuis combien de temps elle existe et quel est son capital enregistré."*

Requirements

• MCP host application (Claude, LLM Studio, VSCode+GHCP/Cline, Cursor, Dive, LibreChat, DeepChat, Chainlit etc.)
• LLM that supports Tool calling (GPT-4.1+ Claude Sonnet/Opus, Gemini, Llama 3.1+, Qwen3.5, etc.)
• (optional) Node.js 24+ (*for development or local run without npx*)

Installation

As a Claude Desktop Extension (easiest)

1. Go to the Releases page and download the latest `zefix.mcpb` file.

2. Double-click it — Claude Desktop opens automatically.

3. Click Install.

Restart Claude Desktop if you do not see `zefix` tool in the list of available tools.

Via npx (recommended for all other MCP hosts)

Add to your MCP host config:

{
  "mcpServers": {
    "zefix": {
      "command": "npx",
      "args": ["-y", "zefix-mcp-unofficial"]
    }
  }
}

npx downloads, caches, and runs the package automatically. No local install required.

From source

git clone https://github.com/your-org/zefix-mcp-unofficial.git
cd zefix-mcp-unofficial
npm install
npm run build

Than add this section to config file of your MCP host application (syntax may vary, check documentation for your MCP host app):

{
  "mcpServers": {
    "zefix": {
      "command": "node",
      "args": ["/absolute/path/to/zefix-mcp-unofficial/dist/index.js"]
    }
  }
}

Tool reference

`get_companies`

Search the Zefix registry. All parameters except `name_or_uid` are optional.

Tips:

• If you know the UID, use it — it will return the most accurate full-detail result.
• If `exactSearch: true` returns no results, retry with `exactSearch: false` and `phoneticSearch: true` combination.
• Results are returned in YAML format, with detail level depending on amount of found companies:
• Results are capped at 100 items.
• The server communicates over stdio (MCP standard transport) — it won't print anything to the terminal when run directly.
• When MCP server queries Zefix REST API at `https://www.zefix.ch/ZefixREST/api/v1/` (public, no authentication required) it submits `User-Agent: zefix-mcp-unofficial` for transparency. You may want to change uf if using this MCP as part of your larger solution.

Development and Debugging

Build

npm run build
# Compiled output goes to dist/index.js

Inspect

Use the MCP Inspector to interactively call tools and inspect responses:

npx @modelcontextprotocol/inspector node dist/index.js

The first run will prompt you to install `@modelcontextprotocol/inspector`. After startup, open the URL shown in the terminal (usually `http://localhost:5173`) to access the inspector UI.

Workflow:

1. Select the `get_companies` tool in the left panel.

2. Fill in parameters (e.g. `name_or_uid: "Berg Digital"`).

3. Click Run and inspect the raw response.

Publishing a new release

Pushing a `v*` tag triggers the GitHub Actions release workflow, which runs two jobs in parallel:

# 1. Bump version in BOTH files (npm will reject publishing over an existing version):
#    - package.json  → "version": "x.y.z"
#    - manifest.json → "version": "x.y.z"

# 2. Commit, tag, push — the tag MUST point to the version-bump commit:
git add package.json manifest.json
git commit -m "chore: release vX.Y.Z"
git tag vX.Y.Z
git push && git push --tags

> ⚠️ Common mistake: creating the tag *before* editing `package.json`/`manifest.json`.

> CI publishes whatever version string is in `package.json` at the tagged commit — the tag name itself is ignored by npm.

> If you tagged too early, move the tag to the correct commit:

> ```bash

> git tag -d vX.Y.Z # delete local tag

> git push origin :refs/tags/vX.Y.Z # delete remote tag

> # edit package.json + manifest.json, then:

> git add package.json manifest.json

> git commit -m "chore: release vX.Y.Z"

> git tag vX.Y.Z

> git push && git push --tags

> ```

> First-time setup (one-off):

> - npm token: create an *Access token* at npmjs.com → add it as a *Repository secret* named `NPM_TOKEN` in *GitHub → Settings → Secrets and variables → Actions*; token lifetime is 90 days (max) - update regularly.

> - GitHub releases: no extra setup needed — the workflow uses the built-in `GITHUB_TOKEN` with `contents: write` permission

License

• MIT.