Features

Send and receive Flows

You can send and receive Kotlin Flows in RPC methods. However, this only applies to the Flow type. StateFlow and SharedFlow are not supported, and there are no plans to add support for them.

            @Serializable
            data class StreamRequest(
                @Contextual
                val innerFlow: Flow<Int>
            )

            @Rpc
            interface MyService : RemoteService {
                fun sendStream(stream: Flow<Int>): Flow<String>

                suspend fun streamRequest(request: StreamRequest)
            }
        

Another requirement is that server-side steaming (flows that are returned from a function), must be the top-level type and the function must be non-suspending:

            @Serializable
            data class StreamResult(
                @Contextual
                val innerFlow: Flow<Int>
            )

            @Rpc
            interface MyService : RemoteService {
                fun serverStream(): Flow<String> // ok
                suspend fun serverStream(): Flow<String> // not ok
                suspend fun serverStream(): StreamResult // not ok
            }
        

Last modified: 04 April 2025