This study examines the integration of a Science, Mathematics, and Technology (SMT) Competency-Based Curriculum (CBC) within Thailand's Education Sandbox initiative, established under the 2019 Education Sandbox Act, to foster innovation, reduce inequalities, and decentralize education management. The research aims to adapt and expand the SMT CBC to align with local contexts, enhancing students' 21st-century skills such as critical thinking, problem-solving, and digital literacy. A three-phase methodology was employed: monitoring curriculum implementation in prototype schools, expanding it to network schools, and developing a systemic framework for broader application. Key findings emphasize the roles of school leaders, teachers, and stakeholders in successful implementation. Visionary leadership, teacher training in competency-based methods, and community resource contributions were identified as essential. Collaborative workshops and knowledge-sharing activities across four provinces facilitated best practice dissemination and sustainable educational networks. Despite challenges like limited teacher readiness and resource constraints, the SMT CBC shows promise in improving educational quality and equity. It prepares students for real-world applications while fostering collaboration among schools and communities. The study highlights the importance of localized policies, stakeholder collaboration, and continuous evaluation, contributing valuable insights for advancing competency-based education in Thailand and globally.