Native server

Ktor supports Kotlin/Native and allows you to run a server without an additional runtime or virtual machine. Currently, running a Ktor server under Kotlin/Native has the following limitations:

a server should be created using embeddedServer
only the CIO engine is supported
HTTPS without a reverse proxy is not supported

Add dependencies

Ktor server in a Kotlin/Native project requires at least two dependencies:

ktor-server-core (core dependency)
ktor-server-cio (the CIO engine)

The code snippet below shows how to add dependencies to the nativeMain source set in your build.gradle.kts file:

kotlin {
    sourceSets {
        nativeMain.dependencies {
            implementation("io.ktor:ktor-server-core:$ktor_version")
            implementation("io.ktor:ktor-server-cio:$ktor_version")
        }
    }
}

To test a Native server, add the ktor-server-test-host artifact to the nativeTest source set:

kotlin {
    sourceSets {
        nativeTest.dependencies {
            implementation(kotlin("test"))
            implementation("io.ktor:ktor-server-test-host:$ktor_version")
        }
    }
}

Configure native targets

Specify the required native targets and declare a native binary using the binaries property:

kotlin {
    val hostOs = System.getProperty("os.name")
    val arch = System.getProperty("os.arch")
    val nativeTarget = when {
        hostOs == "Mac OS X" && arch == "x86_64" -> macosX64("native")
        hostOs == "Mac OS X" && arch == "aarch64" -> macosArm64("native")
        hostOs == "Linux" && (arch == "x86_64" || arch == "amd64") -> linuxX64("native")
        hostOs == "Linux" && arch == "aarch64" -> linuxArm64("native")
        hostOs.startsWith("Windows") -> mingwX64("native")
        // Other supported targets are listed here: https://ktor.io/docs/server-native.html#targets
        else -> throw GradleException("Host OS is not supported in Kotlin/Native.")
    }

    nativeTarget.apply {
        binaries {
            executable {
                entryPoint = "main"
            }
        }
    }
}

Next steps

After configuring your Gradle build script, you can continue to create a Ktor server.

28 July 2026