kotlinx-rpc

kotlinx.rpc is a Kotlin library for adding asynchronous Remote Procedure Call (RPC) services to your applications. Build your RPC with already known language constructs and nothing more!

Usage

First, create your RPC service and define some methods:

@Rpc
interface AwesomeService {
    suspend fun greeting(name: String): String
    
    fun getNews(city: String): Flow<String>
}

In your server code define how to respond by simply implementing the service:

class AwesomeServiceImpl : AwesomeService {
    override suspend fun greeting(name: String): String {
        return "Hello, $name!"
    }
    
    override fun getNews(city: String): Flow<String> {
        return flow { 
            emit("Today is 23 degrees!")
            emit("Harry Potter is in $city!")
            emit("New dogs cafe has opened doors to all fluffy customers!")
        }
    }
}

Then, choose how do you want your service to communicate. For example, you can use integration with Ktor:

fun main() {
    embeddedServer(Netty, 8080) {
        install(RPC)
        routing {
            rpc("/awesome") {
                rpcConfig {
                    serialization {
                        json()
                    }
                }

                registerService<AwesomeService> { AwesomeServiceImpl() }
            }
        }
    }.start(wait = true)
}

To connect to the server use the following Ktor Client setup:

val rpcClient = HttpClient { installRPC() }.rpc {
    url("ws://localhost:8080/awesome")

    rpcConfig {
        serialization {
            json()
        }
    }
}

val service = rpcClient.withService<AwesomeService>()

service.greeting("Alex")    
    
service.getNews("KotlinBurg").collect { article ->
    println(article)
}