Implement your own clients

It is very easy to implement your own clients to follow the pattern. For the system MySystem, you would need to:

1. Depend on the http4k-connect-core artifact
2. Add an Action interface and implementation:
   Kotlin action.kt

   package content.howto.implement_your_own_clients
   
   import org.http4k.connect.Action
   import org.http4k.core.Method.GET
   import org.http4k.core.Request
   import org.http4k.core.Response
   
   interface MySystemAction<R> : Action<R>
   
   data class Echo(val value: String) : MySystemAction<Echoed> {
       override fun toRequest() = Request(GET, "echo").body(value)
       override fun toResult(response: Response) = Echoed(response.bodyString())
   }
   
   data class Echoed(val value: String)
   

3. Add your client interface and HTTP implementation:
   Kotlin client.kt

   package content.howto.implement_your_own_clients
   
   import org.http4k.core.HttpHandler
   
   interface MySystem {
       operator fun <R : Any> invoke(action: MySystemAction<R>): R
   
       companion object
   }
   
   fun MySystem.Companion.Http(http: HttpHandler) = object : MySystem {
       override fun <R : Any> invoke(action: MySystemAction<R>) = action.toResult(http(action.toRequest()))
   }
   

See also the guide on using KSP to generate extension functions for your clients!