aneal99/datafordeler-dar-mcp

MCP server for Danish addresses from **Danmarks Adresseregister (DAR)** on
**Datafordeleren**, the official national data distributor.
DAWA (dawa.aws.dk, api.dataforsyningen.dk) closed on **1 October 2026**
and now returns HTTP 410. Every address tool that was built on it is dead.
Klimadatastyrelsen's replacement is Datafordeleren, which is keyed, bitemporal
and GraphQL-first. This server gives AI agents (Claude, Cursor, VS Code, any
MCP client) the DAR data through ten small, documented tools, with the
coordinates converted to WGS84 and the DAR UUIDs that DAWA also used.
Status: **v0.1, a probe.** It exists to find out whether anyone wants a
maintained MCP layer over Danish public data. Stars, npm downloads and
issues are the signal. It is deliberately thin: no caching, no metering,
one source.
What it does
| Tool | Needs API key | Purpose |
|---|---|---|
| dar_status | no | Connectivity check, configured access paths, sunset countdown |
| dar_get_address | no | One unit address (floor/door) by UUID |
| dar_get_access_address | no | One access address (entrance / husnummer) by UUID |
| dar_list_addresses | no | Units at one access address |
| dar_list_access_addresses | no | Enumerate a street (municipality + road code), a postcode or a cadastral parcel, paginated |
| dar_get_street | no | Named road by UUID or municipality + road code |
| dar_get_postcode | no | Postcode by 4-digit code or UUID |
| dar_search_addresses | **yes** | Prefix search on street names, access addresses and unit addresses |
| dar_graphql | **yes** | Raw GraphQL passthrough to DAR/v2 |
| dar_get_graphql_schema | **yes** | Fetch the GraphQL schema, compacted and filterable |
Every result carries attribution (CC BY 4.0, Klimadatastyrelsen), DAR
status codes with English labels, and points in both EPSG:25832 and WGS84.
Errors are typed (config, bad_request, auth, not_found,
rate_limited, upstream, timeout, network) and say what to do next.
Install
Requires Node.js 20 or newer.
Claude Code:
Claude Desktop, Cursor, VS Code and other clients (mcp.json /
claude_desktop_config.json):
Getting an API key, and why you will need one
Anonymous access to the legacy REST service works today, which is why the
seven lookup tools need no key. Klimadatastyrelsen has announced that
**after 15 January 2027 Datafordeleren only serves authenticated requests**
(API key or OAuth). Text search already needs a key because it runs on the
GraphQL service.
1. Create a free account at (Datafordeler
Administration). An e-mail user is enough; MitID Erhverv is optional.
2. Create an IT-system and add an API key to it.
3. Set DATAFORDELER_API_KEY.
No approval step is needed for DAR. A new key takes up to 15 minutes to
activate; until then the service answers 401 "Unrecognized Authentication
key". Rate limits are not published; the server surfaces HTTP 429 as
rate_limited.
Optional legacy credentials (DATAFORDELER_USERNAME, DATAFORDELER_PASSWORD)
are passed through to the REST service if set.
Examples an agent can chain
With a key:
What the GraphQL service actually does
Verified against the live service on 2026-10-01. Several points differ