Modeling business ecosystems enables ecosystem stakeholders to take better-informed decisions. In this paper, we present an agile framework for modeling a smart city business ecosystem. We follow a design science research approach to conceptualize the agile approach to manage ecosystem models and present the architecture of our framework as design artefact. During the design process, we evaluated ecosystem models that need to adapt with the emerging structures of the business ecosystem. The platform aims at a collaborative modeling process, which empowers end-users to manage the business ecosystem models and underlying data. The evaluation of the platform was conducted with industry partners as part of the presented smart city initative, indicating it usefulness when fulfilling modeling related tasks.