The Seoul Institute — the official municipal policy think tank affiliated with the Seoul Metropolitan Government — and 19 other major urban research bodies from around the world adopted a joint initiative to address pressing global city challenges. The initiative was finalized during the 10th general assembly of the Megacity Think Tank Alliance (MeTTA), held Oct. 22–23 in Beijing. The Seoul Institute, which serves as the permanent secretariat for MeTTA, co-organized the assembly alongside the Beijing Municipal Institute of City Planning and Design (BMICPD). The meeting culminated in the adoption of the Beijing Initiative, a framework defining the alliance’s future role and vision across six strategic priorities: preparing for future urban challenges through joint research, building climate resilience and a just transition, creating people-centered cities, leveraging data and artificial intelligence (AI) for the public good, bridging science with policy and strengthening alliance ties. Following the assembly, participants presented 20 policy and research case studies across three