diff --git a/packages/frontend/src/routes/play/+page.svelte b/packages/frontend/src/routes/play/+page.svelte
index 3260e1a..1ef7096 100644
--- a/packages/frontend/src/routes/play/+page.svelte
+++ b/packages/frontend/src/routes/play/+page.svelte
@@ -127,10 +127,10 @@
 
     recordedEvents.push({
       timestamp,
-      deviceIndex: device.info.index,
-      deviceName: device.name,
-      actuatorIndex: actuatorIdx,
-      actuatorType: actuator.outputType,
+      device_index: device.info.index,
+      device_name: device.name,
+      actuator_index: actuatorIdx,
+      actuator_type: actuator.outputType,
       value: (value / actuator.maxSteps) * 100, // Normalize to 0-100
     });
   }
@@ -313,16 +313,16 @@
 
   function executeEvent(event: RecordedEvent) {
     // Get mapped device
-    const device = deviceMappings.get(event.deviceName);
+    const device = deviceMappings.get(event.device_name);
     if (!device) {
-      console.warn(`No device mapping for: ${event.deviceName}`);
+      console.warn(`No device mapping for: ${event.device_name}`);
       return;
     }
 
     // Find matching actuator by type
-    const actuator = device.actuators.find((a) => a.outputType === event.actuatorType);
+    const actuator = device.actuators.find((a) => a.outputType === event.actuator_type);
     if (!actuator) {
-      console.warn(`Actuator type ${event.actuatorType} not found on ${device.name}`);
+      console.warn(`Actuator type ${event.actuator_type} not found on ${device.name}`);
       return;
     }
 
diff --git a/packages/types/src/index.ts b/packages/types/src/index.ts
index c3fab0a..4b129db 100644
--- a/packages/types/src/index.ts
+++ b/packages/types/src/index.ts
@@ -140,10 +140,10 @@ export interface Stats {
 
 export interface RecordedEvent {
   timestamp: number;
-  deviceIndex: number;
-  deviceName: string;
-  actuatorIndex: number;
-  actuatorType: string;
+  device_index: number;
+  device_name: string;
+  actuator_index: number;
+  actuator_type: string;
   value: number;
 }