The transition to open access (OA) for academic books (monographs, edited collections etc.) has been accelerating over the past few years. Like in journal OA publishing, commercialization opportunities are also clearly present and already widely exploited in OA book publishing. In this book publishing landscape it is important – and still possible – to ensure that open infrastructure services are available to prevent vendor lock-in of OA books and adjacent services. However, as often stated (e.g. in this Knowledge Exchange Position Paper or in statements and reports by SCOSS and Invest in Open Infrastructure (IOI)) this requires strategic and long-term investments by funders and institutions in open infrastructures. The presentation will show how OAPEN and the Directory of Open Access Books (DOAB) over time have expanded and solidified their services to academic libraries and publishers and to researchers and research funders and with concrete examples demonstrate how open infrastructures can successfully collaborate with the key stakeholders the scholarly communication landscape to develop and nurture a healthy OA books ecosystem.