The CitySDK Linked Data API is developed as part of the European CitySDK project. It provides for a unified and direct access to (open) data, with an interface allowing for writing data as well. As such it is an enabler for the ‘read-write city’ where, conceivably, we don’t only read the state of city element, but can also alter that state.

It is designed to work closely with other open source projects as OpenTripPlanner, OpenTripPlanner Analyst, Open311, GTFS, and OpenStreetMap. Based on objects linked to a geometry, the API provides for a linked data (JSON-LD) view of the added data; one query about one object provides results from multiple datasets, annotated using semantic web technologies.


What is the CitySDK Linked Data API?

A web service offering unified and direct access to open data from government, commercial and crowd sources alike. The web service is a standard adopted by 6 European cities.

What does the CitySDK Linked Data API do?

The Linked Data API makes data available in five steps:

  1. It collects data or web services from different sources;
  2. It describes the data;
  3. It links the data to reference datasets when applicable (e.g. from Cadastre or OSM);
  4. It offers the data as a unified service to other applications (API);
  5. It allows those applications to annotate and enrich the data.

Independent of file format, refresh rate or granularity open data is easily accessible for commercial use, research and software developers.

Which datasets are available in this API?

Via the menu link Data you can access a list with all datasets, with a direct link to a sample query in JSON and a map view.

Can you add dataset X?

Yes, probably. Datasets need to be open and have a geolocation. You can send an e-mail to request the addition of a dataset. You can also ask for an account and add the dataset yourself using our (basic) CMS or API.

Who maintains the CitySDK LD codebase?

Waag Society maintains the codebase on GitHub.

Who runs this API instance?

This endpoint is hosted and maintained by Waag Society.

Contact us via e-mail.

For more information on the project and the partner cities, visit the project website.

What are the terms & conditions?

This service is available, for now, with a ‘best effort SLA’ and a fair-use policy. A sustainably hosted instance of the API is in preparation.

Questions, contact

Questions or comments? Send us an e-mail. For more information on the project and the partner cities, visit the project website.