JetBrains recommended using Kotlin Toolchain version 0.13 for most new Kotlin Multiplatform (KMP) projects, describing it as a unified entry point for setting up the Kotlin environment and creating, building, testing, and publishing applications and libraries. The tool targets JVM, Android, iOS, and multiplatform projects, as well as server applications, through declarative configuration and a single command-line interface.
This direction follows Kotlin Toolchain's transition to the Alpha stage earlier in the year, followed by the collection of feedback from Slack channels and the issue tracker. According to JetBrains, improvements to the command-line experience and development environment, along with the addition of web and cinterop support, led to the recommendation to use the tool for new projects. It has also been included in KMP getting-started guides and project-creation flows on the web and in development environments.
Project Creation and Environment Setup
The release introduces the kotlin new command for creating a project through an interactive flow similar to the Kotlin Multiplatform Wizard, in which the developer selects the application type and target platforms. The kotlin init command remains available, but it now matches the new command's behavior by creating project files directly inside the current directory.
The tool's text interface also displays progress bars while downloading required tools, such as JDK and Android SDK packages, iOS simulator runtimes, and compilers. For iOS, the tool now provides clearer diagnostics for Xcode installation issues, license acceptance, and initial launch status. It downloads an iOS simulator runtime when necessary and automatically creates a simulator if one does not already exist.
Android and Apple Improvements
The mechanism for provisioning Android SDK components has been unified between the command line and the development environment. Missing components can now be downloaded when the project is imported into the IDE instead of waiting for a build or run command to be executed. JetBrains has also tightened validation of the namespace and application ID to prevent applications or libraries from being published with sample identifiers such as com.example.app. Developers can also monitor the IDE synchronization status from within the file editor.
On Apple platforms, the release adds support for Swift Package Manager dependencies, including local packages, within modules that support Apple platforms. This makes it possible to import Objective-C interfaces generated from Objective-C or Swift code, using a namespaced name that begins with the swiftPMImport prefix. When publishing multiplatform libraries, Compose Resources metadata and SwiftPM dependencies are included with the build artifacts. Compose Resources can also be resolved from multiplatform libraries provided by third parties.
What Changes in Practice for Developers?
The release reduces the number of separate steps required to set up KMP projects, particularly for developers moving between Android and iOS or working on a clean machine. The iOS and SwiftPM improvements are practically important because they address friction points associated with Apple's native platform tools, while the Android SDK provisioning mechanism helps prevent import failures before the first build.
The tool also includes a server called Hot Reload MCP and skills tailored for AI agents, along with the official Kotlin skills package, which can be installed using the npx skills add kotlin/kotlin-agent-skills command. JetBrains says that internal tests showed agents could create and maintain Kotlin Toolchain projects with greater reliability and lower token consumption, but this is a result reported by the developer and not an independent benchmark.
Kotlin/Native Acceleration and Current Limitations
Kotlin Toolchain stores compiled Kotlin/Native dependencies and reuses them across build operations and even between projects. Project code also receives a per-file cache, allowing only the affected parts to be rebuilt during linking. The feature is based on the settings.kotlin.compileIncrementally setting and supports unoptimized debug files on compatible targets, while .klib files continue to be compiled in full.
JetBrains plans to provide installation through brew install kotlin, make AI skills available by default, support Swift Export once it becomes stable, and simplify application publishing to app stores. However, the company does not yet recommend migrating existing projects built with Gradle, saying it must first understand user feedback and close gaps. Future changes may also require modifications to projects.