fix: interrupt message speech on confirmation

backend/services/brains/workflow_brain.py

@@ -19,6 +19,7 @@ from pipecat.flows import (
     NodeConfig,
 )
 from pipecat.frames.frames import (
+    InterruptionFrame,
     LLMRunFrame,
     LLMUpdateSettingsFrame,
     OutputTransportMessageUrgentFrame,
@@ -1084,6 +1085,14 @@ class WorkflowBrain(BaseBrain):
             ),
         )
         if result.succeeded:
+            if (
+                completion_policy == MESSAGE_CONFIRMATION
+                and result.action == "confirmed"
+            ):
+                # The client-tool result closes the confirmation gate, while
+                # InterruptionFrame closes any speech still owned by this
+                # Message before the next node can enqueue new output.
+                await runtime.queue_frame(InterruptionFrame())
             await self._emit_trace(
                 "message_completed",
                 nodeId=node_id,

backend/tests/test_brains.py

@@ -8,6 +8,7 @@ from unittest.mock import AsyncMock, patch
 from models import AssistantConfig, RuntimeTool
 from pipecat.flows import FlowManager
 from pipecat.frames.frames import (
+    InterruptionFrame,
     LLMContextFrame,
     LLMFullResponseEndFrame,
     LLMFullResponseStartFrame,
@@ -1475,6 +1476,13 @@ class WorkflowBrainTests(unittest.IsolatedAsyncioTestCase):
         async def queue_frame(frame):
             if isinstance(frame, TTSSpeakFrame):
                 events.append(("speech", frame.text))
+            elif isinstance(frame, InterruptionFrame):
+                events.append("interrupted")
+            elif (
+                isinstance(frame, OutputTransportMessageUrgentFrame)
+                and frame.message.get("event") == "message_completed"
+            ):
+                events.append("message_completed")
 
         class OrderedCallEnd(FakeCallEnd):
             def __init__(self):
@@ -1536,6 +1544,7 @@ class WorkflowBrainTests(unittest.IsolatedAsyncioTestCase):
         self.assertEqual(result.action, "confirmed")
         self.assertFalse(call_end.playback_completion.done())
         self.assertEqual(input_states, [False, True])
+        self.assertEqual(events[-2:], ["interrupted", "message_completed"])
 
     async def test_speech_only_message_waits_for_transport_playback(self):
         brain = WorkflowBrain(