diff --git a/apps/magpie/src/protocol.rs b/apps/magpie/src/protocol.rs
index a8a016a..d196a83 100644
--- a/apps/magpie/src/protocol.rs
+++ b/apps/magpie/src/protocol.rs
@@ -26,6 +26,7 @@ pub struct CreatePanel {
     pub id: PanelId,
     pub protocol: String,
     pub script: PathBuf,
+    pub init_msg: Vec<u8>,
 }
 
 /// Sends a panel a message.
diff --git a/apps/magpie/src/service/ipc.rs b/apps/magpie/src/service/ipc.rs
index ad9dce2..cbc4b1e 100644
--- a/apps/magpie/src/service/ipc.rs
+++ b/apps/magpie/src/service/ipc.rs
@@ -130,6 +130,7 @@ impl Client {
                     id,
                     protocol,
                     script,
+                    init_msg,
                 }) => {
                     let mut data = self.data.write();
 
@@ -146,6 +147,7 @@ impl Client {
                         id: window,
                         protocol,
                         script,
+                        init_msg,
                     };
                     let _ = self.window_sender.send_event(msg);
                 }
diff --git a/apps/magpie/src/service/window.rs b/apps/magpie/src/service/window.rs
index fd41d39..53aee3c 100644
--- a/apps/magpie/src/service/window.rs
+++ b/apps/magpie/src/service/window.rs
@@ -21,6 +21,7 @@ pub enum WindowMessage {
         id: usize,
         protocol: String,
         script: PathBuf,
+        init_msg: Vec<u8>,
     },
     CloseWindow {
         id: usize,
@@ -194,11 +195,12 @@ impl WindowStore {
                 id,
                 protocol,
                 script,
+                init_msg,
             } => {
                 println!("Opening window {} with script {:?}", id, script);
                 let module = std::fs::read(script)?;
                 let mut script = self.runtime.load_module(&module)?;
-                let panel = script.create_panel(&protocol, vec![])?;
+                let panel = script.create_panel(&protocol, init_msg)?;
                 let window = Window::new(self.ipc_sender.to_owned(), id, panel, &event_loop)?;
                 let window_id = window.get_id();
                 self.windows.insert(window_id, window);