update

app/core/runner/llm_callback_handler.py

@@ -97,7 +97,7 @@ class LLMCallbackHandler:
                     self.event_handler.pub_message_delta(
                         self.message.id, index, delta.content, delta.role
                     )
-                elif delta["audio"] is not None:
+                elif "audio" in delta and delta["audio"] is not None:
                     if not self.final_message_started:
                         self.final_message_started = True