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BAG API Kadaster (BYOK) — connector documentation

  • MCP endpoint: https://byok-bagkadaster.connectorbay.com/mcp
  • REST API: POST https://byok-bagkadaster.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://byok-bagkadaster.connectorbay.com/openapi.json
  • Transport: Streamable HTTP, stateless, MCP specification 2025-06-18 or later
  • Authentication: your own BAG API Kadaster BAG API key, sent in the X-Upstream-Key header of every request (never stored, logged or cached)
  • Health: https://byok-bagkadaster.connectorbay.com/health · Tool schemas: https://byok-bagkadaster.connectorbay.com/tools.json
  • Publisher: Unify Dynamics LLC · connectorbay.com/byok-bagkadaster · agent@connectorbay.com

What BAG API Kadaster (BYOK) is for

BAG API Kadaster (BYOK) lets an AI assistant read your own BAG API Kadaster data through the BAG API Kadaster API with a key you supply (BAG API key). Read-only: 9 tools (search_addresses, get_address, get_addressable_object, search_addressable_objects_in_bbox, get_dwelling, list_dwellings_in_building, get_building, get_public_space, get_residence_place). The BYOK key travels with each request, is used for that one call only and is never stored, logged or cached; it is only ever sent to api.bag.kadaster.nl. Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by BAG API Kadaster. BAG API Kadaster and its logos are trademarks of their owners and are used only to say which service the connector works with.

Ask your assistant things like:

  • "What address is at postcode 2631CR number 15c?"
  • "Show the address with identification 1926200000508011."
  • "What is addressable object 0599010000165822 used for and how large is it?"
  • "Which addressable objects are inside bbox 230781.67,582665.17,230956.35,582882.42?"
  • "Give me details of dwelling 0268010000036826."
  • "Which dwellings are in building 0268100000021458?"

What it does

  • search_addresses: Search current Dutch addresses by postcode and house number (optionally house letter); returns street, number, postcode, place and object identifiers.
  • get_address: Get one address by its nummeraanduiding identification number.
  • get_addressable_object: Get a dwelling, berth or mooring spot (adresseerbaar object) with its address, use, area and status by identification number.
  • search_addressable_objects_in_bbox: List addressable objects (with addresses) inside a bounding box given in Dutch RD coordinates (EPSG:28992); the box may cover at most 250,000 square metres.
  • get_dwelling: Get one verblijfsobject (dwelling or other usable unit) with purposes of use, floor area, status and the buildings it belongs to.
  • list_dwellings_in_building: List all dwellings (verblijfsobjecten) in one building (pand) with their use, area and status.
  • get_building: Get one building (pand) record by identification number.
  • get_public_space: Get one public space (openbare ruimte, such as a street) by identification number.
  • get_residence_place: Get one place of residence (woonplaats, a town or village) by its identification number.

BYOK key

You bring your own BAG API Kadaster BAG API key (https://formulieren.kadaster.nl/aanvraag_bag_api_individuele_bevragingen_productie). Your assistant sends it in the X-Upstream-Key header with each request. ConnectorBay uses it for that one call only: it is never stored, logged or cached, never shown in an answer, and it is only sent to api.bag.kadaster.nl over https, with no redirects followed. Create a key with the fewest permissions the tools need (read-only if the provider offers it), and revoke it at the provider whenever you like.

Data sources

Live from the BAG API Kadaster API (api.bag.kadaster.nl) with a BYOK key; documentation: https://github.com/lvbag/BAG-API/blob/master/Getting%20started.md. Endpoints checked against that documentation on 2026-10-16.

What it is not

Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by BAG API Kadaster. BAG API Kadaster and its logos are trademarks of their owners and are used only to say which service the connector works with. It is read-only: it never creates, changes, sends or deletes anything in your BAG API Kadaster account.

Built for: Netherlands. Languages: Dutch.