diff --git a/src/dailyai/pipeline/frames.py b/src/dailyai/pipeline/frames.py
index 09f206c87..c3dbe1d25 100644
--- a/src/dailyai/pipeline/frames.py
+++ b/src/dailyai/pipeline/frames.py
@@ -109,6 +109,9 @@ class SendAppMessageFrame(Frame):
     message: Any
     participantId: str | None
 
+    def __str__(self):
+        return f"SendAppMessageFrame: participantId: {self.participantId}, message: {self.message}"
+
 
 class UserStartedSpeakingFrame(Frame):
     pass
diff --git a/src/dailyai/services/base_transport_service.py b/src/dailyai/services/base_transport_service.py
index 316ba7be2..b05c7b1f3 100644
--- a/src/dailyai/services/base_transport_service.py
+++ b/src/dailyai/services/base_transport_service.py
@@ -13,7 +13,6 @@ from enum import Enum
 from dailyai.pipeline.frame_processor import FrameProcessor
 
 from dailyai.pipeline.frames import (
-    ReceivedAppMessageFrame,
     SendAppMessageFrame,
     AudioFrame,
     EndFrame,