fix(voice): expose item_id on UserInputTranscribedEvent

livekit-agents/livekit/agents/voice/agent_activity.py

@@ -1728,7 +1728,9 @@ def _on_input_speech_stopped(self, ev: llm.InputSpeechStoppedEvent) -> None:
 
     def _on_input_audio_transcription_completed(self, ev: llm.InputTranscriptionCompleted) -> None:
         self._session._user_input_transcribed(
-            UserInputTranscribedEvent(transcript=ev.transcript, is_final=ev.is_final)
+            UserInputTranscribedEvent(
+                transcript=ev.transcript, is_final=ev.is_final, item_id=ev.item_id
+            )
         )
 
         if ev.is_final:

livekit-agents/livekit/agents/voice/events.py

@@ -315,6 +315,12 @@ class UserInputTranscribedEvent(BaseModel):
     type: Literal["user_input_transcribed"] = "user_input_transcribed"
     transcript: str
     is_final: bool
+    item_id: str | None = None
+    """Stable id correlating all interim transcripts belonging to the same utterance.
+
+    Mirrors ``llm.InputTranscriptionCompleted.item_id``. Useful for deduplicating
+    repeated interim events from realtime models (e.g. only reacting once per
+    utterance instead of once per streamed delta chunk)."""
     speaker_id: str | None = None
     language: LanguageCode | None = None
     created_at: float = Field(default_factory=time.time)

tests/test_agent_session.py

@@ -92,6 +92,21 @@ async def on_user_turn_completed(self, turn_ctx: ChatContext, new_message: ChatM
 SESSION_TIMEOUT = 60.0
 
 
+def test_user_input_transcribed_event_item_id():
+    """UserInputTranscribedEvent should accept and expose item_id (#6110).
+
+    item_id is the stable correlation key from llm.InputTranscriptionCompleted,
+    forwarded by AgentActivity._on_input_audio_transcription_completed so realtime
+    consumers can dedup repeated interim transcripts belonging to the same utterance.
+    """
+    ev = UserInputTranscribedEvent(transcript="hello", is_final=False, item_id="item_abc123")
+    assert ev.item_id == "item_abc123"
+
+    # item_id remains optional for non-realtime (STT-pipeline) transcripts
+    ev_no_id = UserInputTranscribedEvent(transcript="hello", is_final=True)
+    assert ev_no_id.item_id is None
+
+
 async def test_events_and_metrics() -> None:
     speed = 1
     actions = FakeActions()