Understanding the native SDK wrapper pattern in Kotlin Multiplatform

Kotlin Multiplatform (KMP) has transformed cross-platform development by enabling shared code across Android, iOS, and other platforms while retaining native performance. RevenueCat's Purchases KMP SDK exemplifies this by opting for a wrapper approach over reimplementing platform-specific logic, leveraging existing native SDKs for a unified interface, and maintaining clean, type-safe interfaces. This method ensures state consistency, avoids data duplication, and allows seamless bidirectional conversion between KMP and native types. The SDK uses Kotlin's expect/actual mechanism to define a common API while implementing platform-specific logic, employing a delegation pattern that wraps native SDKs on Android and iOS. This strategy eliminates data synchronization issues and minimizes performance overhead while gracefully handling platform differences by exposing platform-specific features through nullable properties. The wrapper architecture ensures minimal allocation overhead, no data synchronization, and efficient method calls, leveraging Kotlin's property delegation for zero-overhead access. RevenueCat's approach demonstrates that wrapping native SDKs can maintain performance and API quality, providing a scalable foundation for future multiplatform development while emphasizing delegation over duplication for clean and efficient code.