NVTX (NVIDIA Tools Extension Library)

NVTX (NVIDIA Tools Extension) is a cross-platform API designed to annotate source code with rich metadata that can be consumed by developer profiling and debugging tools. It allows developers to insert markers, ranges, and events directly into their applications, providing contextual insight into how code executes on CPUs and GPUs. These annotations are visualized in tools such as NVIDIA Nsight Systems and Nsight Compute, enabling developers to identify performance bottlenecks, track execution flow, and correlate application behavior with hardware activity. The API is written in C and includes wrappers for C++ and Python, making it accessible across different programming environments and workloads. NVTX is particularly valuable in high-performance computing and AI workloads where understanding concurrency, memory usage, and kernel execution is critical for optimization.