diff --git a/src/adk_firestore_sessionmanager/firestore_session_service.py b/src/adk_firestore_sessionmanager/firestore_session_service.py
index a9d5b4c..07f61d2 100644
--- a/src/adk_firestore_sessionmanager/firestore_session_service.py
+++ b/src/adk_firestore_sessionmanager/firestore_session_service.py
@@ -417,6 +417,8 @@ class FirestoreSessionService(BaseSessionService):
         if event.partial:
             return event
 
+        t0 = time.monotonic()
+
         app_name = session.app_name
         user_id = session.user_id
         session_id = session.id
@@ -463,6 +465,19 @@ class FirestoreSessionService(BaseSessionService):
         else:
             await session_ref.update({"last_update_time": event.timestamp})
 
+        # Log token usage
+        if event.usage_metadata:
+            meta = event.usage_metadata
+            logger.info(
+                "Token usage for session %s event %s: "
+                "prompt=%s, candidates=%s, total=%s",
+                session_id,
+                event.id,
+                meta.prompt_token_count,
+                meta.candidates_token_count,
+                meta.total_token_count,
+            )
+
         # Trigger compaction if total token count exceeds threshold
         if (
             self._compaction_threshold is not None
@@ -471,6 +486,21 @@ class FirestoreSessionService(BaseSessionService):
             and event.usage_metadata.total_token_count
             >= self._compaction_threshold
         ):
+            logger.info(
+                "Compaction triggered for session %s: "
+                "total_token_count=%d >= threshold=%d",
+                session_id,
+                event.usage_metadata.total_token_count,
+                self._compaction_threshold,
+            )
             await self._compact_session(session)
 
+        elapsed = time.monotonic() - t0
+        logger.info(
+            "append_event completed for session %s event %s in %.3fs",
+            session_id,
+            event.id,
+            elapsed,
+        )
+
         return event