krusty

A Kotlin compiler written in Rust.

A drop-in replacement for kotlinc on the JVM: the same command-line flags in, and .class files byte-for-byte identical to kotlinc's out, from a single native binary.

Download · Source · Supported language

Usage

krusty src/ -d out/                          # compile to a class directory
krusty src/ -d mylib.jar -module-name mylib  # or to a jar
krusty -cp deps.jar:classes/ App.kt -d out/  # with a classpath

Binaries for Linux, macOS and Windows (x86_64, arm64) are on every release. From source: cargo build --release -p krusty-cli.

What it does

• Output is diffed against the real kotlinc: class files, @kotlin.Metadata, .kotlin_module.
• Every build runs JetBrains' codegen/box suite; the badge shows the pass rate.
• kotlinx.serialization and KSP are supported.
• krusty-lsp is a Kotlin language server on the same compiler, with a Zed extension.