Nordic Data MCP Server

A Model Context Protocol server that gives AI agents (Claude, Cursor, Claude Code, ChatGPT, Copilot, etc.) direct access to official European business data across 15 EU countries.

Look up companies, validate VAT numbers, run KYB reports, screen against sanctions lists, autocomplete addresses, and resolve LEI ownership — all from inside your AI assistant.

DK · NO · SE · FI · IE · UK · FR · DE · CZ · PL · LV · EE · NL · BE · LU

NL and DE require a Starter+ subscription (free-tier API keys receive HTTP 402 upgrade_required). On paid tiers, NL calls cost 5x quota units and DE calls cost 3x; all other countries cost 1x.

Quick start

1. Get an API key

Sign up at addonnordic.com and grab your NORDIC_API_KEY. Free tier available.

2. Add to Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%/Claude/claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "nordic-data": {
      "command": "npx",
      "args": ["-y", "nordic-data-mcp"],
      "env": {
        "NORDIC_API_KEY": "YOUR_KEY_HERE"
      }
    }
  }
}

Restart Claude Desktop. You should see "nordic-data" appear in the tools menu.

3. Add to Cursor

In Cursor settings → MCP → Add new server, or edit ~/.cursor/mcp.json:

{
  "mcpServers": {
    "nordic-data": {
      "command": "npx",
      "args": ["-y", "nordic-data-mcp"],
      "env": {
        "NORDIC_API_KEY": "YOUR_KEY_HERE"
      }
    }
  }
}

4. Add to Claude Code

claude mcp add nordic-data --env NORDIC_API_KEY=YOUR_KEY_HERE -- npx -y nordic-data-mcp

5. Add to ChatGPT (Pro, Business, or Enterprise)

ChatGPT supports remote MCP servers as custom connectors. No API key needed from you — the hosted server handles upstream authentication.

1. ChatGPT → Settings → Connectors → Add custom connector
2. URL: https://nordic-data-mcp-production.up.railway.app/mcp
3. Done — all 11 tools are available immediately.

Custom connectors require a ChatGPT Pro, Business, Team, or Enterprise plan.

6. Add to Claude.ai (web)

Same hosted endpoint, no local install:

1. Claude.ai → Settings → Connectors → Add custom connector
2. URL: https://nordic-data-mcp-production.up.railway.app/mcp
3. Done.

Available tools

Example agent prompts

"Look up CVR 61056416 in Denmark" → calls lookup_company { country: "dk", id: "61056416" } → Carlsberg A/S

"Run a full KYB report on Equinor (NO 923609016)" → calls kyb_full { country: "no", id: "923609016" }

"Is LU26375245 a valid VAT number?" → calls validate_vat { country: "LU", vat_number: "26375245" }

"Screen these names against sanctions: Vladimir Putin, Acme Corp, John Smith" → calls screen_sanctions { names: [...] }

"Find the LEI for Tesco UK (00445790) and include parent and subsidiaries" → calls lookup_lei { mode: "reverse", country: "uk", id: "00445790" }

Country / ID format reference

For validate_vat, country codes are uppercase and cover the broader EU plus GB (use GB, not UK — HMRC requires GB).

Configuration

The only environment variable you need to set is:

That's it. The MCP server connects to the hosted Nordic Data API for you.

Self-hosting (remote HTTP transport)

For remote MCP hosting (e.g. Anthropic Connectors, Smithery, web-based clients), deploy the bundled Streamable HTTP transport:

npm install
npm run build
NORDIC_API_KEY=sk_... npm run start:http   # listens on :$PORT (default 3000)

Endpoints:

• GET /healthz — health check (returns version + status)
• ALL /mcp — public MCP endpoint. No key required; all upstream calls are billed to the server's own NORDIC_API_KEY (freemium / discovery). Per-IP rate-limited.
• ALL /mcp/auth — authenticated MCP endpoint. Requires Authorization: Bearer ndk_... on every request; each call is billed to that customer's own key + quota.

Both are session-based via the Mcp-Session-Id header.

Connecting a remote client

This server uses static API-key authentication, not OAuth. How you connect depends on your client:

• Header-capable clients (Claude Code, Cursor, Smithery, Claude.ai / ChatGPT custom connectors): point them at …/mcp/auth and supply your key as Authorization: Bearer ndk_.... Each request is billed to your own tenant + quota.
• Generic / auto-discovery clients that only know "URL + OAuth": point them at the public …/mcp (no key). Otherwise such clients attempt OAuth Dynamic Client Registration (POST /register) and fail — this server has no OAuth endpoints by design and answers them with a clear JSON oauth_not_supported error (not a sign-in flow).
• Local clients: prefer the stdio package — npx -y nordic-data-mcp with NORDIC_API_KEY set (see Quick start above).

Full OAuth 2.1 (so arbitrary external clients can self-onboard with their own key) is a planned Phase-2 item, not yet implemented.

A railway.toml is included for one-click deploy on Railway:

1. New Project → Deploy from GitHub repo → select Mnymann/nordic-data-mcp
2. Set Root Directory to nordic-data-mcp
3. Add env var NORDIC_API_KEY
4. Railway auto-detects the config, builds, and exposes a public HTTPS URL

Design notes

• Thin adapter. No business logic, no caching, no transformations. Each tool maps 1:1 to a Nordic Data API endpoint.
• No PII in logs. Request and response bodies are never logged.
• API key required. The process refuses to start without NORDIC_API_KEY.
• Rate limiting. The backend enforces per-key quotas; the HTTP transport additionally applies a per-IP limit on the public /mcp endpoint as defense-in-depth (tunable via PUBLIC_RATE_LIMIT / PUBLIC_RATE_WINDOW_MS). Caching is handled upstream.
• Inputs are validated with zod before any HTTP call.

Contributing

Issues and PRs welcome at github.com/Mnymann/nordic-data-mcp.

Please do not include API keys, request bodies, or response payloads in bug reports.

Disclaimer

Nordic Data returns informational decision-support aggregated from official and public sources. It is not legal, compliance, financial, or professional advice, and not a definitive determination. KYB reports, sanctions/PEP matches, adverse-media hits, and risk scores are signals to review, not verdicts — verify independently and apply your own professional judgment before acting. Use of the service is subject to the AddonNordic Terms.

License

MIT © AddonNordic ApS