diff --git a/src/SupApp/index.ts b/src/SupApp/index.ts
index 9bf0d58..ea670b5 100644
--- a/src/SupApp/index.ts
+++ b/src/SupApp/index.ts
@@ -81,6 +81,9 @@ namespace SupApp {
   export function onMessage(messageType: string, callback: Function) {
     electron.ipcRenderer.addListener(`sup-app-message-${messageType}`, (event, ...args) => { callback(...args); });
   }
+  export function sendMessage(windowId: number, message: string) {
+    electron.ipcRenderer.send("send-message", windowId, message);
+  }
 
   export function getCurrentWindow() { return currentWindow; }
   export function showMainWindow() { electron.ipcRenderer.send("show-main-window"); }
diff --git a/src/ipc.ts b/src/ipc.ts
index 095568e..bbc9b10 100644
--- a/src/ipc.ts
+++ b/src/ipc.ts
@@ -30,6 +30,7 @@ electron.ipcMain.on("choose-folder", onChooseFolder);
 electron.ipcMain.on("choose-file", onChooseFile);
 electron.ipcMain.on("authorize-folder", onAuthorizeFolder);
 electron.ipcMain.on("check-path-authorization", onCheckPathAuthorization);
+electron.ipcMain.on("send-message", onSendMessage);
 
 const secretKeys = new Map<Electron.WebContents, string>();
 
@@ -96,3 +97,10 @@ function onCheckPathAuthorization(event: Electron.IpcMainEvent, secretKey: strin
   const authorization = canReadWrite ? "readWrite" : (canExecute ? "execute" : null);
   event.sender.send("check-path-authorization-callback", ipcId, normalizedPath, authorization);
 }
+
+function onSendMessage(event: Electron.IpcMainEvent, windowId: number, message: string, args: any[] = []) {
+  const window = electron.BrowserWindow.fromId(windowId);
+  if (window == null) return;
+
+  window.webContents.send(`sup-app-message-${message}`, ...args);
+}