JetBrains has released Kotlin Toolchain 0.12, expanding library publishing capabilities to include JVM, Android, iOS, and WebAssembly (Wasm). Developers can now use a single tool configuration to generate the necessary versions for all supported platforms.
Compared to version 0.11, which only supported the JVM platform, the new update allows for the simultaneous generation of shared application programming interfaces, platform-specific library files, source code, and platform identification information.
The toolchain now enables the direct construction and execution of Wasm web applications, supporting custom index.html files and other web resources. It also automatically retrieves required npm packages for Kotlin Multiplatform libraries.
Additionally, JetBrains updated the Compose Multiplatform UI framework. This update introduces Compose Hot Reload via the command line, allowing developers to load interface changes in real-time while the application is running.
The new version also supports starting an MCP server, enabling AI agents to interact with applications running via Compose Hot Reload. These agents can reload the app, restart it, capture window screens, and read the interface component structure.