Open data is data in a machine-readable format that is made available for everyone to use. Access to public sector open data is one of the basic rights of the information society and has a significant impact on the transparency of state management, citizen involvement, economic revitalization, research, public sector efficiency, etc. By using open source data, you agree to the terms of the Creative Commons 3.0 BY-SA license. ERJK's open data services allow IT experts flexible and immediate access to information generated during work. Open data is issued through an application interface (API) in JSON format. Open data API documentation can be found on the page: https://erjk.ee/avaandmed. If you have any questions, write to firstname.lastname@example.org.