EDR API

The goal of an EDR API is to query environmental data in a spatio-temporal manner. This data can be queried using different query patterns. You can, for example, query the data at a position or in a spatial cube. The available query endpoints depend on the Collection you are querying.

The API contains Collections (a dataset, for example observations). Within a collection there are one or more Instances (a subtype of the Collection, e.g. unvalidated).

The datasets in the table below are currently available in the KNMI EDR API. More collections may be added in the future.

Requesting an API token

In order to make API requests, you’ll need an API key for the EDR API. You can request an API key for the EDR API in the API Catalog. To request an API key, you will need to register for an account. You can do this by clicking the “Register” button in the top right corner of the page. Once registered, you can request an API key by clicking on the appropriate “Request API Key” button on the API Catalog page. You will receive an email with your API key.

The table below lists the rate limits and quotas for the API keys.

• To see which collections are available inside the EDR you can make use of the https://api.dataplatform.knmi.nl/edr/v1/collections endpoint.
• To get information about a specific collection you can use the https://api.dataplatform.knmi.nl/edr/v1/collections/{collection_name} endpoint.
• To get information about the instances in a collection you can use the https://api.dataplatform.knmi.nl/edr/v1/collections/{collection_name}/instances endpoint.
• For querying the data endpoints you can use the endpoints under the “Collection data queries” and the “Instance data queries” sections of the detailed technical documentation.

The API response will be in the following formats (dependent on the endpoint): GeoJSON, Coveragejson or JSON.

CoverageJSON and GeoJSON are special types of JSON. Each have their own tools and libraries to process and visualise them.

GeoJSON

GeoJSON is a combination of a Well-Known-Text (WKT) geometry type and additional information about this geometry inside a properties field. There is an online tool to visualize GeoJSON.

Example tools and libraries to work with GeoJSON in your own application:

• KNMI geoweb (JS)
• Leaflet (Web)
• Bokeh (Python)
• Plotly (Python)

CoverageJSON

CoverageJSON is a special type of JSON aimed at representing spatio-temporal data. It can be used to efficiently transfer parts of a big dataset to a client. It supports various types of geometries (called Domains). There is an online tool to visualize CoverageJSON.

Example tools and libraries to work with CoverageJSON:

• Leaflet plugin (Web)
• covjson-reader (Javascript)
• covjson-pydantic (Python)

import sys

import requests

api_version = "v1"
collection = "observations"
base_url = f"https://api.dataplatform.knmi.nl/edr/{api_version}/collections/{collection}"
token = "<YOUR API KEY>"
headers = {"Authorization": token}


def metadata():
    r = requests.get(base_url, headers=headers)
    r.raise_for_status()
    return r.json()


def locations():
    r = requests.get(base_url + "/locations", headers=headers)
    r.raise_for_status()
    return r.json()


def position(params):
    r = requests.get(base_url + "/position", params, headers=headers)
    r.raise_for_status()
    return r.json()


def main():
    md = metadata()
    print(md["extent"]["temporal"]["interval"])

    locs = locations()
    print([f["properties"]["name"] for f in locs["features"]])

    params = {
        "coords": "POINT(5.14527777777778 51.8577777777778)",
        "datetime": "2022-07-19T06:00:00Z/2022-07-19T18:00:00Z",
        "parameter-name": "t_dryb_10",
    }
    print(position(params))


if __name__ == "__main__":
    sys.exit(main())