Ktor Server Auto-Routing

Kobold uses Kotlin Symbol Processing (KSP) to build upon Ktor Type Safe Routing.

Kobold will maintain your ktor server routing based on class structures so all you need in your ktor server setup is:

 embeddedServer(Netty, port = 8080) {
        install(ContentNegotiation) {
            json()
        }
        install(Resources)
        autoRoute()
    }.start(wait = true)

Kobold will detect any class annotated with @Resource and @Kobold and add it to the autoRouter() function:

@Kobold @Resource("/login")
data object LoginPage: KPost<MyLoginData, MyLoginResponse>
{
 
	override val process: (MyLoginData) -> MyLoginResponse = {
		MyLoginResponse("I got your Post, here is the response!")
	}
}

By extending KPost<T, R> you direct Kobold to create a POST route for /login which will accept T as the post body and respond with R. T implements KRequest and R implement KResponse.

AuthRouter will capture the request and processes it via a lambda to your personal process implementation.

The resulting route will look like this:

fun Application.autoRouter() {
  routing {
    post<LoginPage> {
      val response : MyLoginResponse = it.process(call.receive())
      call.respond(response,  typeInfo = TypeInfo(MyLoginResponse::class))
    }
  }
}

Routing can get very complex as your app grows and Kobold will keep it clean for you. Learn more about using Sealed Subclasses to maintain hierarchy.

Last modified: 12 February 2025