The project is an open-source development focused on software interoperability within the AEC (Architecture, Engineering, and Construction) industry. It connects the open-source 3D data collaboration platform Speckle with the open-source geometric modeling kernel Open Cascade. Speckle has emerged in recent years as an alternative to traditional file-based exchanges such as IFC (Industry Foundation Classes); it connects a wide range of AEC software through plug-ins and web-based interface, in a very flexible way. On the other hand, Open Cascade is a set of libraries for geometric processing, providing the low-level foundation required by any CAD (Computer-Aided Design) or BIM (Building Information Modeling) software. Our project prototypes a Speckle connector for Open Cascade. This opens up opportunities to integrate software built on Open Cascade—such as FreeCAD, as well as numerous academic and specialized applications that benefit from Open Cascade’s open nature—into the Speckle ecosystem. In the longer term, it also enables the Speckle platform to support functionalities requiring geometric computation once models have been extracted from their authoring software. During this initial phase, progress has focused on the development of two scripts for sending and receiving data between the Speckle and Open Cascade environments. It is primarily designed to convert geometries between the two objects models. Implemented in Python, it includes the conversion of BReps, translating between the specific ways in which the two object models handle curves and surfaces, trimming and holes, all of which are characteristic of the digital representation of such entities.