Will focus on the tool support for b-APIs. WP4 will turn the algorithms and the verification, validation, and reverse-engineering techniques identified in WP2 and WP3 into provably correct tool chains to support developers. Moreover, we will create b-APIs for the tools chains provided in WP4. Such b-APIs will be maintained and published so as to make them accessible to the wider public. This solution will, at the same time, simplify IP issues (APIs of proprietary software will allow to control what functionalities companies want to expose) and enable new collaborations between the partners and external stakeholders.