Introduction

Info

This guide assumes that you:

• understand what an API is and know how you can make REST API calls
• have a valid Nexus Web API token

Not the case? Check the API Basics first before continuing here.

Root and authentication

Nexus Web API can be reached at https://nexus.stellaspark.com/api/v1/.

The Nexus Web API token must be provided as URL query parameter:

curl "https://nexus.stellaspark.com/api/v1/{api_service}/?token={web_api_token}"

Nexus API services for data consumption

Nexus offers standardized services for geospatial data, so that data exchange between software programs can take place without much additional work. The API services differ in the type of data that they serve.

API Service	Meaning	Data type	Formats
WFS	Web Feature Service	Vector data	csv, json, xml, kml, shp
WMS	Web Map Service	Raster data as pre-rendered maps	png, jpg
WCS	Web Coverage Service	Raw raster data	geotiff
Events	Events service	Timeseries events	csv
Data sources	Overview of data sources	Metadata	json
Data subscriptions	Overview of data subscriptions	Metadata	json
Sync tasks	Sync tasks with data connections	Metadata	json

Let's try it out

Get a GeoJSON with spatial objects

For retrieving a GeoJSON file with all weather stations in the Sandbox world, we use the WFS API service.

curl "https://nexus.stellaspark.com/api/v1/wfs/?world=sandbox&request=getfeature&typenames=weather_station&outputformat=json&count=1&token={web_api_token}"

This request returns the following (GeoJSON) response:

{
    "type": "FeatureCollection",
    "features": [
        {
            "type": "Feature",
            "id": "weather_station.3",
            "geometry": {
                "type": "Point",
                "coordinates": [
                    140802.69754,
                    456881.77153
                ]
            },
            "geometry_name": "centroid",
            "properties": {
                "dc_id": 18,
                "id_src": "260",
                "label": "De Bilt",
                "id": 3
            },
            "bbox": [
                140802.69754,
                456881.77153,
                140802.69754,
                456881.77153
            ]
        }
    ],
    "totalFeatures": 3,
    "numberMatched": 3,
    "numberReturned": 1,
    "timeStamp": "2021-08-13T08:56:02.507Z",
    "crs": {
        "type": "name",
        "properties": {
            "name": "urn:ogc:def:crs:EPSG::28992"
        }
    },
    "bbox": [
        140802.69754,
        456881.77153,
        140802.69754,
        456881.77153
    ]
}

Get a pre-rendered raster

For obtaining a pre-rendered map of the Sandbox world, you'd need to use the WMS API service.

curl "https://nexus.stellaspark.com/api/v1/wms/?layers=sandbox:waterbody&token={web_api_token}"

The API returns the following image with return code 200:

Connect Nexus to a GIS application

Using WMS or WFS, you connect Nexus to common desktop GIS applications, like QGIS or ArcGIS (version 10.1 and higher). Check the tutorial Using Nexus data in QGIS to see how you can visualize Nexus tables directly in QGIS.