diff --git a/sim/api.ts b/sim/api.ts
index a44cca6f..61c5a972 100644
--- a/sim/api.ts
+++ b/sim/api.ts
@@ -30,6 +30,13 @@ namespace pxsim.unity {
 
     //% blockId=helloUnity block="helloUnity"
     export function helloUnity() {
+        window.addEventListener('message', (event) => {
+            const command = event.data.unityCommand;
+            const data = event.data.unityData;
+            if (!!command) {
+                console.log(`Received command ${command} from unity with data: ${data}`);
+            }
+        });
         if (!window.parent) {
             console.log('MakeCode: Parent not found');
         } else {