Ktor — Async Web Framework for Kotlin by JetBrains

# Via IntelliJ IDEA or Gradle
gradle init --type kotlin-application

Add to build.gradle.kts:

plugins {
    id("io.ktor.plugin") version "3.0.0"
    kotlin("plugin.serialization") version "2.0.0"
}

dependencies {
    implementation("io.ktor:ktor-server-core")
    implementation("io.ktor:ktor-server-netty")
    implementation("io.ktor:ktor-server-content-negotiation")
    implementation("io.ktor:ktor-serialization-kotlinx-json")
}

fun main() {
    embeddedServer(Netty, port = 8080) {
        install(ContentNegotiation) { json() }

        routing {
            get("/api/assets") {
                call.respond(listOf(Asset("react", 230000)))
            }
            post("/api/assets") {
                val asset = call.receive<Asset>()
                call.respond(HttpStatusCode.Created, asset)
            }
        }
    }.start(wait = true)
}

@Serializable
data class Asset(val repo: String, val stars: Int)