Kotlin Language Server is a Language Server Protocol implementation that provides official Kotlin support for Visual Studio Code and other LSP-compatible editors.
The tool solves the problem of enabling rich Kotlin language features in editors beyond JetBrains IDEs. It works by implementing the Language Server Protocol, with its core built on the IntelliJ IDEA codebase and the IntelliJ Kotlin Plugin. This foundation allows it to deliver IntelliJ-powered code completion, diagnostics, and quick fixes without requiring developers to use a full IDE. The server supports JVM projects built with Gradle or Maven, with experimental Android Gradle Plugin support, and offers semantic highlighting, refactoring, code formatting, documentation navigation, and call hierarchy features.
Developers choosing this tool should understand it is in alpha state, meaning core architecture is stable but feature completeness and stability of existing functionality remain in development. It suits teams working on Kotlin projects in VS Code or other LSP-compatible editors who want IntelliJ-quality language features without the overhead of a full IDE. The tool is designed to work with any editor supporting LSP, though releases are primarily tested against VS Code. Support for Kotlin Multiplatform projects is noted as coming in future releases. The language server is partially closed-source, drawing on proprietary components from JetBrains Air and Fleet products alongside its open-source foundation.
Development activity shows consistent engagement with the project's alpha status. The team maintains an official VS Code Marketplace extension with clear migration guidance for users switching from older extension IDs. Installation options span multiple platforms through Homebrew and manual setup, with documented CLI usage. The project actively tracks community feedback through its issue system and provides editor integration scripts maintained by the community for non-VS Code environments.
