UM-Bridge (the uncertainty quantification (UQ) and modeling bridge) provides a unified interface for numerical models that is accessible from any programming language or framework. It is primarily intended for coupling advanced models (e.g. simulations of complex physical processes) to advanced statistical or optimization methods for UQ without requiring the model and UQ algorithms to share a common computational environment. By allowing containerization, numerical models become portable and reproducible. This improves separation of concerns between the fields, and lays the groundwork for unified UQ benchmark problems. Further, high peformance computing is simplified through a pre-defined configuration for cloud environments, allowing to run many parallel instances of any UM-Bridge model container.