Danish property data, as MCP tools
An AI agent that needs to check a Danish building, resolve an address or look up a company should not need a bespoke integration for each register. Grundfast exposes twelve typed tools over the Model Context Protocol, authenticated with the same bearer key as the REST API and metered the same way.
POST /mcpConnect it
A streamable-HTTP remote with a bearer header. Published in the official MCP registry as dk.grundfast/danish-address-property-data.
{ "mcpServers": { "grundfast": { "type": "streamable-http", "url": "https://api.grundfast.dk/mcp", "headers": { "Authorization": "Bearer gf_live_..." } } } }
The tools
One tool per register surface. Each is read-only and returns the same shape as its REST equivalent.
| Tool | Does |
|---|---|
bbr_ejendom | Full BBR property rollup — buildings, units, land — for a BFE number. |
bbr_historik | The same property as it stood at an earlier date. |
matrikel_ejendom | Cadastral parcels and ejerlav name from Matriklen for a BFE. |
adresse_soeg | Search Danish addresses by text. |
adresse_opslag | Look up one address by its DAR UUID. |
adresse_historik | How an address changed over time. |
adresse_datavask | Clean a messy address string; ranked candidates with confidence bands. |
adgangsadresse_reverse | Nearest addresses to a WGS84 coordinate. |
cvr_virksomhed | Danish company by CVR number — name, status, form, industry, location. |
dhm_hoejde | Terrain and surface elevation at a coordinate. |
stednavne_naer | Official place names near a coordinate. |
geodanmark_bygninger | Per-building footprint polygons (WGS84) for a BFE. |
Read-only by design
Every tool is a lookup against a public register. Nothing mutates, personal ownership data is not exposed, and per-key rate limits and quotas mean an agent in a loop hits a limit rather than a surprise invoice. A gf_test_ key is never billed.
Give your agent Danish property data
Create a free key, add the block above to your MCP client, and the tools show up on the next restart.
See also
Frequently asked questions
What is MCP?
The Model Context Protocol is an open standard for connecting AI assistants and agents to external tools and data. An MCP server exposes a set of typed tools that a model can call directly, instead of you writing glue code for each integration.
How do I add Grundfast to my MCP client?
Point your client at https://api.grundfast.dk/mcp as a streamable-http remote and send your Grundfast key as an Authorization: Bearer header. The server is also published in the official MCP registry as dk.grundfast/danish-address-property-data, so clients that read the registry can find it by name.
Does it cost extra?
No. MCP calls authenticate, rate-limit and meter through exactly the same path as the REST API, against the same plan. A gf_test_ key lets an agent explore the tools without being billed.
Which model or client does it work with?
Any MCP-capable client. The transport is streamable HTTP with bearer authentication, which is the standard remote-server shape — there is nothing model-specific in it.
Is it safe to let an agent call it?
The server is read-only: every tool is a lookup against a public register. There is no endpoint that mutates data, and personal ownership data is not exposed. Rate limits and quotas apply per key, so an agent in a loop hits a limit rather than a bill you did not expect.