Kotlin Multiplatform v2.2.20-Beta2 Release Notes & Developer Guide

Kotlin v2.2.20-Beta2 delivers significant K2 compiler stability improvements, expanded contract system capabilities for operators and generics, and enhanced WebAssembly support with better exception handling and Long type integration. Major tooling updates include Gradle cross-compilation automation, kotlin-android-extensions removal, and improved Analysis API performance for IDE developers.

Highlights

• K2 compiler improvements: fixed interface extension errors, local class evaluation in IDE, and recursive value class stack overflow issues
• WebAssembly enhancements: improved exception handling, fixed nullable generic casts, and better JS interop support
• Contract system expansion: now supports operator functions, generics in type assertions, and improved return value checking
• JavaScript/Wasm Long support: BigInt representation in ES6 mode and Long usage in exported declarations
• Analysis API surface improvements: new expression information provider and performance optimizations for validity checks
• Gradle tooling: automatic cross-compilation detection, KotlinJvmAndroidCompilation support, and deprecated kotlin-android-extensions removal