Worked on enhancing the robustness of asynchronous operations in the modelcontextprotocol/csharp-sdk repository by implementing CancellationToken support for both client and server request handlers. This addition allowed in-flight asynchronous requests to be cancelled gracefully, improving resource utilization and responsiveness in scenarios prone to latency or long-running tasks. The approach involved propagating the CancellationToken through handler registrations to ensure consistent cancellation behavior across the stack. Utilizing C# and leveraging skills in API development, asynchronous programming, and error handling, the work aligned with business goals of predictable performance and improved developer experience in managing cancellation flows within complex async workflows.