geonorge

name	geonorge
description	Norwegian geographic data — address search, reverse geocoding, county (fylke) and municipality (kommune) lookup using AT.Common.GeoNorge. Use this skill when finding an address from a text query, finding the closest address to coordinates, resolving Norwegian counties/municipalities, or finding which municipality contains a geographic point.
license	MIT
metadata	{"domain":"backend","tags":"geonorge geography address geocoding coordinates fylke kommune norway dotnet"}

GeoNorge Skill — Arbeidstilsynet/dotnet-common

Arbeidstilsynet.Common.GeoNorge (AT.Common.GeoNorge.Publish) wraps the GeoNorge Adresser API and Fylker og Kommuner API in strongly-typed .NET clients.

---

Installation

dotnet add package Arbeidstilsynet.Common.GeoNorge

---

Dependency Injection Setup

builder.Services.AddGeoNorge();

An optional GeoNorgeConfig can be passed to override the base URL (default https://ws.geonorge.no/):

builder.Services.AddGeoNorge(new GeoNorgeConfig
{
    BaseUrl = "https://custom-geonorge-proxy.example.com/"
});

This registers IAddressSearch and IFylkeKommuneApi.

---

Address Search (IAddressSearch)

Text search

Find addresses matching a free-text query:

public class AddressService(IAddressSearch addressSearch)
{
    public async Task Example()
    {
        var result = await addressSearch.SearchAddresses(new TextSearchQuery
        {
            SearchTerm = "Karl Johans gate 1, Oslo"
        });
        // result?.Elements contains matching Address records

        // Get only the first match as a Location (lat/lon)
        var location = await addressSearch.QuickSearchLocation(new TextSearchQuery
        {
            SearchTerm = "Karl Johans gate 1, Oslo"
        });
    }
}

Point search (reverse geocoding)

Find addresses within a radius of given coordinates:

// Find all addresses within 1 000 m of a point
var result = await addressSearch.SearchAddressesByPoint(new PointSearchQuery
{
    Latitude = 59.9139,
    Longitude = 10.7522,
    RadiusInMeters = 1000
});

// Find the single closest address
var closest = await addressSearch.GetClosestAddress(new PointSearchQuery
{
    Latitude = 59.9139,
    Longitude = 10.7522,
    RadiusInMeters = 1000
});

Pagination

Both search methods accept an optional Pagination parameter:

var result = await addressSearch.SearchAddresses(
    new TextSearchQuery { SearchTerm = "Brannfjordveien" },
    new Pagination { PageIndex = 0, PageSize = 10 }
);

---

County and Municipality (IFylkeKommuneApi)

public class LocationService(IFylkeKommuneApi fylkeKommuneApi)
{
    public async Task Example()
    {
        // Get all counties
        var fylker = await fylkeKommuneApi.GetFylker();

        // Get all municipalities
        var kommuner = await fylkeKommuneApi.GetKommuner();

        // Get detailed county info (includes municipalities)
        var fylkerFull = await fylkeKommuneApi.GetFylkerFullInfo();

        // Get a specific county by number
        var oslo = await fylkeKommuneApi.GetFylkeByNumber("03");

        // Get a specific municipality by number
        var osloKommune = await fylkeKommuneApi.GetKommuneByNumber("0301");

        // Reverse-lookup: which municipality contains this point?
        var kommune = await fylkeKommuneApi.GetKommuneByPoint(new PointQuery
        {
            Latitude = 59.9139,
            Longitude = 10.7522
        });
    }
}

---

Key Model Types

Type	Description
TextSearchQuery	Free-text address search — SearchTerm (required) plus optional filters: FuzzySearch, Adressenavn, Poststed, Postnummer, Kommunenummer, Gardsnummer, Bruksnummer
PointSearchQuery	Coordinates + radius for reverse geocoding
PointQuery	Coordinates (Latitude, Longitude) + Epsg (default 4326) for fylke/kommune lookup
Address	Full address record (street, number, municipality, coordinates)
Location	Latitude + Longitude point + optional Epsg coordinate system code
Pagination	PageIndex (page index) + PageSize (page size)
PaginationResult<T>	Elements + paging metadata
Fylke	Norwegian county
Kommune	Norwegian municipality

---

Extension Methods

QuickSearchLocation is a convenience method on IAddressSearch that returns the Location (lat/lon) of the first search result:

Location? location = await addressSearch.QuickSearchLocation(
    new TextSearchQuery { SearchTerm = "Youngstorget, Oslo" }
);

Returns null if no address is found.

---

Adding GeoNorge — Checklist

1. dotnet add package Arbeidstilsynet.Common.GeoNorge
2. Register with services.AddGeoNorge()
3. Inject IAddressSearch for address/geocoding operations
4. Inject IFylkeKommuneApi for county/municipality operations
5. Handle null returns (network errors or no results)