Gary Chan developed a dedicated error handling framework for the KP Protocols Client SDK in the KodyPay/kp-protocols-clientsdk repository. He introduced new Protocol Buffers definitions, including an error.proto file with a KpError enum, to extend gRPC status codes with explicit error types. Gary also created a poc.proto file defining a PocService and ErrorCodePoc RPC, enabling robust testing of error code handling within the client SDK. His work focused on design and prototyping, establishing a consistent approach to error reporting and testability using protobuf and gRPC, and laying a scalable foundation for future error-driven workflows across client applications.