This workshop examines how technological, contractual, and financial dependencies are developing between a small number of AI model providers and their business users. It presents the state of the art in research on platform power, innovation dependence and AI governance, with particular attention to the limits of existing regulatory frameworks such as the EU’s Digital Markets Act. The workshop focuses on how such dependencies can be empirically identified despite limited public data and high information asymmetries. It introduces mixed-method research design combining interviews, contract analysis and financial data to map opaque dependency structures. Key methodological challenges, such as access limitations and capturing evolving dependencies, are discussed in detail. The workshop concludes by showing how empirical findings can be theorised and developed into academic publications with clear policy relevance.