October 19th 2026

ElaadNL releases open-source code for Matter and S2

A step towards better interoperability

Homes are increasingly equipped with devices that offer flexible control capabilities, such as charging points, heat pumps, home batteries and inverters. To control these devices intelligently and in a coordinated way, home energy management systems (HEMS) and devices must be able to communicate reliably with one another. A lack of technical interoperability remains a significant barrier.

Within the Residential Flexibility project, open-source solutions have therefore been developed for communication between HEMS and smart devices across three use cases. The release of the Matter and S2 code aims to make it easier for companies to implement and reuse the code and work together on its further development. This helps to bring smart devices and HEMS solutions to consumers sooner, making it easier for them to use their own solar energy, benefit from dynamic energy prices and avoid peak loads on the grid.

A thorough security process with ENCS

Alongside functionality and interoperability, cybersecurity was a key requirement during development. A thorough security process was carried out with support from the specialist organisation ENCS. The code and the relevant design and implementation decisions were assessed from a security perspective. Findings from this process were addressed before the open-source code was made publicly available. Security was therefore an integral part of development, rather than being treated as a final step.

Available on GitHub

The open-source code for Matter and S2 is available for download via ElaadNL’s GitHub page as of Monday 19 October 2026. Developers, suppliers and manufacturers of smart devices and HEMS are invited to use and test the code and contribute to its further development.

About Residential Flexibility

Residential Flexibility is a project in which ElaadNL works with industry partners to improve technical interoperability between HEMS and smart devices. The project supports and accelerates the development of scalable solutions that make better use of flexibility in homes, benefiting consumers and contributing to a stable energy system. It uses the communication protocols S2, Matter, EEBUS and OCPP, with OpenADR providing an additional communication layer for external systems. A Modbus converter is also being developed to connect devices already installed in consumers’ homes to a future-proof energy management system that complies with the project’s standards. The EEBUS and Modbus converter code will be released soon. During the upcoming test event, hosted by ElaadNL on 25 and 26 November, manufacturers and developers will be able to test the new code in practice with smart devices and HEMS from other participants.