As explained in the section 3.4. "Provision of market data and execution notice in the event of failures" on J-GATE Connectivity Manual,
the market price date on the business day can be retrievable as CSV format by requesting it to OSE.
For broadcast message, you are able to retrieve BD2,BD70,BO16,BI7,BL51,BL52,BU124,BU126.
Please also check the attached sample file.