You can use Helsinki’s Linked Events API to retrieve event data of several City of Helsinki divisions and the Helmet library service in a uniform format. The geographic data is linked to the City of Helsinki’s office register, which contains information on, for example, the accessibility of the venues.
You can search the API based on, for example, the date, location and keywords.
The API data is updated once an hour.
The licence for the data is, in principle, Creative Commons BY 4.0. In some images available through the API, the license is a more limited “event only”, i.e. the image must not be taken out of context. There is a separate mention of this in connection with the event data.