diff --git a/src/runtime/error.rs b/src/runtime/error.rs
index e9392fb9ce6521357cbaab2f40e6936a99a7c9b7..26e5792541c411071f4b4a98e6907138b9d23391 100644
--- a/src/runtime/error.rs
+++ b/src/runtime/error.rs
@@ -12,6 +12,16 @@ pub enum ConnectError {
     EndpointSetupError(SocketAddr, EndpointError),
     SetupAlgMisbehavior,
 }
+#[derive(Eq, PartialEq, Copy, Clone, Debug)]
+pub enum AddComponentError {
+    NoSuchComponent,
+    NonPortTypeParameters,
+    CannotMovePort(PortId),
+    WrongNumberOfParamaters { expected: usize },
+    UnknownPort(PortId),
+    WrongPortPolarity { port: PortId, expected_polarity: Polarity },
+    DuplicateMovedPort(PortId),
+}
 ////////////////////////
 #[derive(Debug, Clone)]
 pub enum SyncError {