Timmy Cheung enhanced the KodyPay/kp-protocols-clientsdk repository by standardizing payment identifier fields within the pay.proto API definition. He replaced legacy fields with payment_reference and idempotency_uuid, aligning request and response messages to improve consistency and reduce integration risk across services. Using Protocol Buffers and applying API design best practices, Timmy’s work enabled safer retries and streamlined analytics by ensuring uniform identifiers throughout the payment flow. This update also laid the foundation for future API versioning and extensibility, supporting long-term maintainability. The focused scope addressed a core protocol need, demonstrating depth in protocol design and attention to cross-service reliability.