URBAN TESTBEDS.JR intends to encourage experimentation as a significant means to build resilient communities. Focus is on the co-design of urban testbeds for tangible experiences in sustainability and climate mitigation action with and for young citizens. Aim is to strengthen the joint participatory capacity for young citizens, local public authorities and enabling interest groups. Participatory capacity is seen as a prerequisite to be inclusive in regard to a resilient community, here young citizens, to respond to climate and sustainability challenges. Experimentation includes urban testbed experimentation, service experimentation and experimental governance. The capacity building has three components: 1) Artificial Intelligence supported understanding and deconstructing of climate plans and their transformational goals/paths relevant for local experimentation, 2) Scoping tangible urban experimentation in testbeds, and 3) Storytelling the impact and perspective of the experimentation by means of data-based storytelling. Local authorities and interest groups in Germany, Denmark and Sweden will liaise with higher research institutions partners. Outcome will be a “Playbook for UrbanTestbeds.JR” with solution chapters on urban testbed identification & scoping, co-design sprints with young citizens for testbed scenarios and urban data storytelling, and an artificial intelligence solution module to support the understanding and deconstruction of climate and sustainability plans.