The aim of the study is to identify the role of business environment institutions (BEIs) in shaping digital entrepreneurial ecosystems by assessing the structure of support available to micro, small and medium-sized enterprises (MSMEs), with particular emphasis on online services. An attempt was made to fill the theoretical, empirical and methodological gap resulting from the insufficient number of studies integrating the supply and demand perspectives, taking into account regional diversity and a comprehensive assessment of the digitization processes of BEI services. Original definitions of the terms "digitization of support and cooperation between BEIs and MSMEs" and "online services provided by BEIs" have been developed, which organize the research area and provide the basis for further analyses. The research was carried out in two stages: in the first stage, an analysis of secondary data was carried out on the level of digitization of MSMEs and the scope of BEI activities, in the second stage, primary research was carried out in the form of a survey among MSMEs and a survey using the method of observing the digital activity of BEIs on a nationwide scale. Triangulation of methods was used, which made it possible to compare the results from both sources. The result of the research is the development of a model of the digital entrepreneurial ecosystem in the areas of BEI activities covering four dimensions: activities, participants, motivations and organization of activities. This model allows to diagnose and design activities supporting the development of MSMEs in the digital economy and to formulate recommendations for public policy. The results of the research provide analytical tools and conceptual frameworks that can be used in future analyses, including those of an international nature.