diff --git a/api.capnp b/api.capnp
index 0046740..b890575 100644
--- a/api.capnp
+++ b/api.capnp
@@ -123,6 +123,9 @@ struct Machine {
         
         setProperty @3 (property :PropertyMap.Property) -> ();
         # Write ONE Machine Property identified by it's key
+
+        sendRawData @4 (data :Data) -> ();
+        # send a blob of arbitrary data to the machine
     }