The European Commission is making significant efforts to regulate and harmonise the digital single market, covering areas such as data processing, data flows, interoperability, exchanges, and the roles, responsibilities, and potential liabilities of owners, designers, and service providers. This Chapter takes an internal perspective of legal governance, exploring the regulatory models and instruments crucial to constructing legal ecosystems. Initially, there were nine European common data spaces to be regulated in real-time, with an additional tenth space related to the European Open Science Cloud (EOSC). Four more spaces (including human heritage and tourism) have been recently added. This Chapter delves into the proposed instruments for regulation. The central argument is that the regulation and development of platforms within the platform-driven economy, particularly in the banking and financial sectors, go beyond traditional frameworks of hetero, co-, and self-regulation. Instead, these processes involve intra-technological and computational regulation. Therefore, regulatory approaches must incorporate a formal inside-outside and a middle-out/inside-out approach derived from intelligent information systems. A comprehensive framework will be outlined to encompass hard and soft law, policies, and ethics within the context of emerging scenarios fostered by Web 3.0, Industries 4.0 and 5.0. This Chapter will delve into the common and specific regulatory instruments and mechanisms proposed for these data spaces, thoroughly examining the technical and legal frameworks required to incept and flesh out these digital ecosystems.