This study aims to investigate the adaptation of Thai academic libraries in response to changes driven by increased reliance on emerging technologies, referred to as Library 4.0. Employing Garvin's Three Ms. Framework, the meaning, management, and measurement aspects were examined to identify the principles of Library 4.0, policies and practices, as well as measurement alterations. A qualitative case study approach, using document analysis and in-depth interviews, was employed. Eight academic libraries were purposefully selected based on criteria, including their age, size, and interests. The findings indicated that the concept of Library 4.0 had driven Thai academic libraries to integrate digital technologies into both front-end services and back-office operations. While continuing to prioritize support for teaching and research, the libraries had expanded their roles to address broader societal impacts. The importance of effectively utilizing measurement approaches, particularly data analytics, was highlighted to demonstrate the value and impact of libraries in the digital era. A comprehensive framework produced from this study contributes to a holistic understanding of the adaptation of Thai academic libraries. Given the pivotal role of environmental dynamics, this framework provides guidelines for future investigations, ensuring that academic libraries remain relevant in preparation for the transition to Library 5.0.