Kadaster APIbagviewer.kadaster.nl ↗
Access Dutch BAG registry data: address autocomplete, building details, residential unit info, historical records, and coordinate-based lookup via 8 endpoints.
What is the Kadaster API?
This API exposes 8 endpoints covering the Dutch National Address and Building Registry (BAG), operated by Kadaster. You can search and resolve addresses using search_address_autocomplete, retrieve full building records including GeoJSON geometry and construction year via get_pand_details, inspect residential unit surface area and usage purposes through get_verblijfsobject_details, and trace the complete lifecycle of any BAG object with get_object_history. All 16-digit BAG identification numbers are supported across object types.
curl -X GET 'https://api.parse.bot/scraper/aa9c1132-257f-455d-b9ef-51f44e637f01/search_address_autocomplete?query=Dam+1%2C+Amsterdam' \ -H 'X-API-Key: $PARSE_API_KEY'
Typed, relational, agent-ready
A generated client with real types, enums, and the links between objects — the structure a flat JSON response can't carry. Autocompletes in your editor and reads cleanly to coding agents.
- Fully typed · autocompletes
- Objects link to objects
- Typed errors & pagination
Typed Python client. Set up the SDK in your uv project, then pull this API’s typed client:
uv add parse-sdk uv run parse init uv run parse add --marketplace bagviewer-kadaster-nl-api
uv run parse add --marketplace pulls a pinned snapshot of this canonical API — it won’t change underneath you. To customize it, subscribe and swap to your own copy.
from parse_apis.dutch_bag_viewer_api import BAGViewer, ObjectType
bag = BAGViewer()
# Search for addresses in Amsterdam
for address in bag.addresses.search(query="Dam 1, Amsterdam"):
print(address.weergavenaam, address.postcode)
break
# Advanced search by city and street
for address in bag.addresses.advanced_search(woonplaats="Amsterdam", straat="Kalverstraat"):
print(address.id, address.straatnaam)
break
# Get full address details by ID
addr = bag.addresses.get(id="adr-2a8dc1af055da20b8bcdc8e4dbda1eaa")
print(addr.weergavenaam, addr.adresseerbaarobject_id)
# Get verblijfsobject summary with enum
vbo = bag.verblijfsobject("0363010003761571")
summary = vbo.summary(object_type=ObjectType.ADRESSEERBARE_OBJECTEN)
print(summary.identificatie, summary.oppervlakte, summary.status)
# Get building history
pand = bag.pand("0363100012168052")
for version in pand.history():
print(version.versie, version.begin_geldigheid, version.status)
# Search buildings by coordinates
for building in bag.pands.search_by_coordinates(x="121394", y="487383"):
print(building.identificatie, building.oorspronkelijk_bouwjaar, building.status)
Autocomplete/typeahead search for addresses, cities, and BAG numbers using the PDOK Locatieserver API. Returns up to 10 matching address suggestions from the BAG registry. Query matches against street names, house numbers, postcodes, and city names. Results are ranked by relevance score.
| Param | Type | Description |
|---|---|---|
| queryrequired | string | Search keyword for address lookup (e.g. 'Dam 1, Amsterdam', 'Kalverstraat 10'). |
{
"type": "object",
"fields": {
"docs": "array of address suggestion objects with fields: weergavenaam, id, straatnaam, postcode, woonplaatsnaam, adresseerbaarobject_id, nummeraanduiding_id, centroide_rd, centroide_ll, huisnummer, gemeentenaam",
"numFound": "integer total number of matching results"
},
"sample": {
"data": {
"docs": [
{
"id": "adr-2a8dc1af055da20b8bcdc8e4dbda1eaa",
"bron": "BAG",
"type": "adres",
"postcode": "1012JS",
"huisnummer": 1,
"straatnaam": "Dam",
"centroide_ll": "POINT(4.8937175 52.37329259)",
"centroide_rd": "POINT(121394 487383)",
"gemeentenaam": "Amsterdam",
"weergavenaam": "Dam 1, 1012JS Amsterdam",
"woonplaatsnaam": "Amsterdam",
"nummeraanduiding_id": "0363200003761447",
"adresseerbaarobject_id": "0363010003761571"
}
],
"start": 0,
"numFound": 371,
"numFoundExact": true
},
"status": "success"
}
}About the Kadaster API
Address Search and Resolution
The search_address_autocomplete endpoint accepts a free-text query parameter (e.g. 'Dam 1, Amsterdam') and returns up to 10 address suggestions from the BAG registry, each including weergavenaam, straatnaam, postcode, woonplaatsnaam, and an adresseerbaarobject_id. The id field from those results feeds directly into lookup_address_by_id, which resolves a single full address record by its PDOK locatieserver ID. For structured lookups, advanced_search accepts discrete woonplaats (required), straat, and huisnummer parameters and returns a docs array with numFound.
Building and Unit Detail
get_pand_details takes a 16-digit pand_id and returns the building's oorspronkelijkBouwjaar (original construction year), status, documentdatum, and a geometrie field containing a GeoJSON Polygon in the Dutch RD coordinate system. get_verblijfsobject_details covers residential units: it returns oppervlakte (surface area in m²), a gebruiksdoelen array listing usage purposes, status, and HAL _links pointing to the associated main address (heeftAlsHoofdAdres) and parent building (maaktDeelUitVan). get_object_summary combines these views and returns an _embedded object with nested address and building sub-objects alongside the verblijfsobject record.
Coordinate Search and History
search_by_coordinates accepts RD system x and y coordinates and returns an _embedded.panden array of building objects near that point, each containing identificatie, geometrie, oorspronkelijkBouwjaar, and status. This is useful for map-click workflows where you have a screen or map coordinate rather than an address string.
get_object_history requires both an object_id and an object_type (panden, verblijfsobjecten, or nummeraanduidingen) and returns _embedded.voorkomens, an ordered array of historical versions. Each voorkomen captures the full object state at that revision — geometry, status, and document references — making it possible to reconstruct how a building or address changed over time.
The Kadaster API is a managed, monitored endpoint for bagviewer.kadaster.nl — not a raw scraper you maintain. Every endpoint is automatically health-checked on a schedule, and when bagviewer.kadaster.nl changes and a check fails, the API is automatically queued for repair and re-verified. It is built to keep working as the site underneath it changes.
This isn't an official bagviewer.kadaster.nl API — it's an independent, maintained REST wrapper over public data. Where the source has no official API (or only a limited one), Parse gives you a stable contract over a source that never promised one, and keeps it current. Need a new endpoint or field? You can revise it yourself in plain English and the agent rebuilds it against the live site in minutes — contributing the change back to the shared API is free.
Will this API break when the source site changes?+
Is this an official API from the source site?+
Can I fix or extend this API myself if I need a new endpoint or field?+
What happens if I call an endpoint that has an issue?+
- Auto-suggest Dutch address input fields using
search_address_autocompleteresults includingpostcodeandwoonplaatsnaam. - Enrich property records with building age and footprint by calling
get_pand_detailsfor theoorspronkelijkBouwjaarand GeoJSON geometry. - Validate and normalize Dutch addresses in CRM or logistics systems using
lookup_address_by_idfor canonical BAG records. - Display residential unit surface area and usage classification on real estate listings via
get_verblijfsobject_detailsoppervlakteandgebruiksdoelenfields. - Audit address and building status changes for compliance or due diligence using
get_object_historyvoorkomens. - Identify buildings at a clicked map location by passing RD coordinates to
search_by_coordinates. - Build structured address search forms for Dutch municipalities using
advanced_searchwithwoonplaats,straat, andhuisnummerinputs.
| Tier | Price | Credits/month | Rate limit |
|---|---|---|---|
| Free | $0/mo | 100 | 5 req/min |
| Hobby | $30/mo | 1,000 | 20 req/min |
| Developer | $100/mo | 5,000 | 100 req/min |
One credit = one API call regardless of which marketplace API you call. Exceeding the rate limit returns a 429 response. Authenticate with the X-API-Key header.
Does Kadaster offer an official developer API for BAG data?+
What coordinate system does `search_by_coordinates` use, and can I pass WGS84 lat/lon?+
x and y values — for example, x=121394 and y=487383. WGS84 latitude/longitude is not accepted directly. You would need to convert coordinates before calling the endpoint. You can fork the API on Parse and revise it to add a conversion step or accept WGS84 inputs.What does `get_object_history` return, and which object types are supported?+
_embedded.voorkomens, an array where each entry is a complete snapshot of the object at a specific point in its lifecycle — including geometry, status, and document references. Supported object_type values are panden, verblijfsobjecten, and nummeraanduidingen. Standplaatsen and ligplaatsen history are not currently covered. You can fork the API on Parse and revise it to add those object types.