About the metadata export

Click here for the interface overview [API documentation]

umwelt.info offers the following interfaces: 

In addition to the search for environmental and nature conservation information through our website, our application programming interface (API) is a method to directly retrieve the metadata of the datasets. Besides the export based on our internal metadata scheme, various interfaces will be made available in accordance with established standards. Network partners from civil society, science and administration were asked in September 2024 which standards they prefer as users of the portal, as there are currently various standards for transferring metadata. Users primarily preferred the standards CKAN, DCAT-AP (German), schema.org, CSW or Dublin Core. Accessing our dataset in CKAN metadata format is now possible. Additional exports via schema.org and others will follow.

CKAN

To process metadata automatically, umwelt.info offers established standards. The standardisation process may however result in information loss. For example, the CKAN standard only allows the naming of a single author or publisher, while our internal schema allows multiple entries in this field. 

To ensure that information is still available which might be assigned ambiguously, the CKAN standard provides the ‘Extras’ field, which allows any number of freely definable entries. The use of this field follows the principles of the CKAN export of metadata from govdata.org.

Our CKAN-compatible metadata schema is documented here . The conversion of our internal schema into this format can best be understood in the source code .

At umwelt.info two API endpoints are offered: 

• package_search allows a search to be executed and responds with the contents of the results matching the search result. The search with a wildcard ‘*’ allows you to query the entire metadata index on umwelt.info.
• package_show allows you to query individual data records in CKAN format.

Why is it important to offer a standardised metadata export? 

For the umwelt.info search, information is stored in an internal metadata format that maps the content from integrated data offers as complete and flexible as possible. The API makes metadata reusable through this internal schema. However, a stable API cannot be offered with the internal metadata schema as it has to be constantly adapted.

Thus, umwelt.info also offers stable and established standards for metadata export. A standard export allows a comparison of metadata from umwelt.info with other sources whose APIs are based on the same established standard.