As part of automated AMQP communication on the Intraday Electricity and Gas Market, a modification of the interface is planned whereby the XML message format will be replaced by the binary data format Protocol Buffers. There will be no changes on the user side when using the Intraday Electricity and Gas Market application or mobile applications.

The automated communication interface of the Intraday Electricity Market (IDM Electricity) and the Intraday Gas Market (IDM Gas) towards market participants is currently implemented using the AMQP protocol with message transmission in XML format. Due to the need to ensure adequate performance and stability of the central XBID system, and also with regard to the future development of intraday trading and the legislative requirement to transition intraday cross-border capacity allocation to the Flow-based mechanism, the SIDC project (Single Intraday Coupling) will introduce a change in the message communication format for data exchanges between the central XBID solution and local trading systems (LTS) operated by NEMOs. The XML message format will be replaced by a binary format based on Protocol Buffers.

From the perspective of the transition to the new communication format on the XBID side, the communication concept itself (the existing portfolio of communication scenarios and the AMQP protocol) will remain unchanged. In light of this planned change, it will also be necessary to adapt the communication interface on the OTE CS side to the intended Protocol Buffers binary format, so that the increased performance and communication speed can also be reflected in the interface between OTE and market participants.

The change of the communication format will apply to the automated communication of both IDM Electricity and IDM Gas towards market participants. The provided documentation includes the following:

• An updated version of the Electricity and Gas Message Format Manuals, reflecting the new communication message format. In addition, XLSX mapping tables for electricity and gas are available, providing a mapping of the existing XML attribute names to the new BIN API equivalent attribute names – see the downloadable materials below.
• In subsequent steps, the actual protobuf definitions (.proto files) will be published:
  • For electricity by 20 March 2026
  • For gas by 15 May 2026

Subsequently, we expect:

• Start of testing with market participants in Q4 2026
• Go-live of the change in Q1 2027

Further information and details regarding the planned testing will be regularly provided via the OTE website and via email communication.