Here we present an open-source behavioral platform and software solution for studying fine motor skills in mice performing reach-to-grasp task. We describe steps for assembling the box, training mice to perform the task, and processing the video with the custom software pipeline to analyze forepaw kinematics. The behavioral platform uses readily available and 3D-printed components and was designed to be affordable and universally reproducible. We provide the schematics, 3D models, code, and assembly instructions in the open GitHub repository.