Guides · API

Reverse geocoding API for the Netherlands

Netherlands reverse geocoding (omgekeerd geocoderen): send WGS84 latitude and longitude, get the nearest official address from the national BAG register with distance in metres, postcode, city, municipality, province, BAG ids and CBS buurt and wijk codes, plus other nearby addresses. For delivery, field service, mobility, real estate and mapping agents. Source: Kadaster BAG via PDOK.

0.002 USDC per call · GET /v1/address/reverse · free preview at /v1/address/reverse/preview

Parameters

Name	Required	Description
`lat`	yes	Latitude in decimal degrees (WGS84), e.g. 52.0836
`lon`	yes	Longitude in decimal degrees (WGS84), e.g. 4.2919

Example request

curl "https://factline.dev/v1/address/reverse?lat=52.0836&lon=4.2919"
# 402 Payment Required: pay with an x402 client (USDC on Base), or send
# Authorization: Bearer <your Factline API key>

Example response

{
  "query": {
    "lat": 52.0836,
    "lon": 4.2919
  },
  "address": {
    "label": "Laan van Meerdervoort 100A, 2517AS 's-Gravenhage",
    "street": "Laan van Meerdervoort",
    "house_number": 100,
    "house_letter": "A",
    "house_number_addition": null,
    "postcode": "2517AS",
    "city": "'s-Gravenhage",
    "municipality": "'s-Gravenhage",
    "municipality_code": "GM0518",
    "province": "Zuid-Holland"
  },
  "distance_m": 1.5,
  "location": {
    "lat": 52.08358839,
    "lon": 4.29191123,
    "crs": "WGS84"
  },
  "bag": {
    "addressable_object_id": "0518010000432205",
    "address_id": "0518200000432204"
  },
  "neighbourhood": {
    "code": "BU05182245",
    "name": "Zeeheldenkwartier"
  },
  "district": {
    "code": "WK051822",
    "name": "Wijk 22 Zeeheldenkwartier"
  },
  "other_nearby": [
    {
      "label": "Laan van Meerdervoort 100, 2517AS 's-Gravenhage",
      "distance_m": 2.2
    },
    {
      "label": "Laan van Meerdervoort 100B, 2517AS 's-Gravenhage",
      "distance_m": 2.8
    }
  ],
  "source": "Kadaster BAG via PDOK Locatieserver"
}

Use it from an AI agent

Agents with an x402 wallet call the URL directly and pay per request. Assistants that speak MCP connect to https://factline.dev/mcp. Full reference: docs, OpenAPI, llms.txt. Businesses: API keys with a free trial.

Questions

How much does the Reverse geocoding API for the Netherlands cost?

0.002 USDC per call, paid per request with x402 (no account), or included in a Factline API key plan with a free trial. Calls that fail are not charged.

Can I try it for free?

Yes: GET /v1/address/reverse/preview with the same parameters validates your input and shows what the paid answer contains, at no cost.

Where does the data come from?

Official public registers and open data, named with their licence in every response (source field) and at /.well-known/x402-license-provenance.