Kotlin Toolchain 0.12.0: Multiplatform Libraries and Wasm Apps

Kotlin Toolchain 0.12.0 introduces multiplatform library publishing and a preview of WebAssembly (Wasm) application support. The update allows developers to publish libraries for multiple platforms—JVM, Android, iOS, and Wasm—using the same configuration. This simplifies dependency management by automatically providing the common API, platform-specific artifacts, sources, and module metadata. Additionally, Cinterop bindings are now published both commonized and per platform, enabling users to access C APIs without manual interop setup. The Wasm preview supports building web applications with features like customizing `index.html` and fetching npm dependencies from Kotlin Multiplatform libraries. The update also includes improvements to Compose Hot Reload, terminal UI diagnostics, and IDE support for Android and iOS development. Notably, Kotlin Toolchain now enforces JDK 17 as the minimum supported version and raises the Kotlin compiler minimum to 2.2.20. Developers can explore these features by updating existing projects or following the Kotlin Toolchain’s getting started guide.