Swift export

❗️ Swift export is in very early stages of development. Things change very quickly, and documentation might not catch up at times.

Swift export is a tool that generates Swift bindings for public Kotlin declarations, making it possible to share business logic between Kotlin and Swift applications.

How to try

❗️ (Yep, again) Swift export is far even from Alpha state at the moment. We are working hard to make it feature-complete and stable.

Sample project

swift-export-sample provides an example of using Swift export in a typical KMP project.

Kotlin Playground

You can play with Swift export at the Kotlin playground to get familiar with the Swift API it generates.

A few notes:

• Playground implementation inserts stub() in functions instead of compiler bridges to make the generated API a bit cleaner.
• It takes a bit of time to include the latest changes from Swift export on Playground.

Separate artifacts

You can play with Swift export without KGP. Note that it might be a bit tricky at the moment:

• Swift export requires a Kotlin/Native distribution to resolve references to stdlib.
• Swift export depends on the not-yet-stable Analysis API.
• Swift export API surface is not stable by any means.
• Versions of Swift export and Analysis API artifacts might not be the same.

1. Add Maven repositories:

maven("https://maven.pkg.jetbrains.space/kotlin/p/kotlin/dev")

2. Add dependencies:

// Make sure to use the latest versions of artifacts.
val kotlinVersion = "2.0.20-dev-+"

implementation("org.jetbrains.kotlin:kotlin-native-utils:$kotlinVersion")
implementation("org.jetbrains.kotlin:kotlin-compiler-embeddable:$kotlinVersion")
implementation("org.jetbrains.kotlin:swift-export-embeddable:$kotlinVersion")

3. Call Swift export APIs:

val inputModule = InputModule.Binary("ModuleName", Path("path-to-input-klib"))
val config = SwiftExportConfig(
    outputPath = Path("path-to-output-artifacts"),
    distribution = Distribution(
        konanHome = "$HOME/.konan/some-kotlin-native-distribution"
    ),
)
val result = runSwiftExport(inputModule, config)
// explore the result!

More info

• Architecture overview
• Kotlin to Swift mapping
• Swift wrappers to Kotlin bridges

Slack channel

We use the #swift-export Slack channel as the place to share our progress, and we encourage you to join us there!