Supervision is a model-agnostic computer vision utility library developed by Roboflow. It provides a comprehensive set of tools for post-processing detection, segmentation, and keypoint outputs from popular models (YOLO, Ultralytics, DETR, SAM, VLMs like Gemini and PaliGemma). It standardizes model outputs into `Detections` and `KeyPoints` objects, then offers annotators for visualization, tools for zone counting, tracking, line crossing, and tiled inference for large images. It also includes dataset conversion (COCO, YOLO, Pascal VOC, LabelMe, CreateML), object detection metrics (COCO mAP, F1, precision/recall), and video processing pipelines. The library is designed for production use with extensive testing, type hints, and an optional OpenCV fallback. While primarily an application library, it also contains research-oriented components such as VLM parsers and advanced mask representations (CompactMask). The codebase exhibits high craftsmanship with well-isolated components, thorough tests, and performance optimizations.