The SEA-EU Open Science Workshop (6-7 October 2025, Hamburg) brought together ambassadors from three SEA-EU member universities (Kiel University, the University of Split School of Medicine, and the University of Malta) alongside experts from the Open Science Learning GATE (GATE), Open Science (OS) and legal experts. The workshop aimed to identify shared priorities and develop coordinated approaches to strengthening OS at the intersection with Artificial Intelligence (AI) across the SEA-EU Alliance. Participants provided insights on OS from their universities and on GATE’s evidence-based analysis of OS guiding thoughts, practices, and OS–AI developments. Together, these inputs formed the basis of an emerging SEA-EU OS Capacity-Building Roadmap, structured around five action areas:(1) Awareness and Training(2) Policy and Evaluation Harmonisation(3) Responsible AI Integration(4) Legal and Structural Support(5) Lighthouse Projects Initiative A Lighthouse Projects Initiative emerged as a central mechanism: researcher-driven, scalable demonstrations of OS in practice that can enhance reproducibility, collaboration and policy development across the alliance. Furthermore, a discussion with national funders (German Research Foundation; DFG) and Croatian Science Foundation) enriched strategies for successful OS implementation. Funders welcomed the so-called Lighthouse Projects as constructive and non-prescriptive. A DFG representative responded particularly positively to GATE’s evidence-based work, highlighting its value for understanding how OS is implemented in practice. As next steps, SEA-EU representatives and GATE will refine the roadmap with funder input, integrate outcomes into the GATE Report 2025, continue structured funder engagement, and support advancing a Lighthouse Projects Initiative as pilots for coordinated OS implementation across SEA-EU institutions.