Initial commit of current state

echo_guard.py

@@ -0,0 +1,43 @@
+"""Stop the agent from hearing itself.
+
+On laptop speakers with no acoustic echo cancellation, the microphone picks up
+whatever Kokoro just said. The recognizer transcribes it, the aggregator treats
+it as a user turn, and the agent answers its own greeting — which is exactly
+what happens without this.
+
+Pipecat's ``AlwaysUserMuteStrategy`` mutes while the bot is speaking, but
+unmutes the instant playback ends, and the tail of that audio is still in the
+input buffer. This keeps the mute up for a short while afterwards.
+"""
+
+import time
+
+from pipecat.frames.frames import BotStartedSpeakingFrame, BotStoppedSpeakingFrame, Frame
+from pipecat.turns.user_mute.base_user_mute_strategy import BaseUserMuteStrategy
+
+
+class EchoGuardUserMuteStrategy(BaseUserMuteStrategy):
+    """Mute the user while the bot speaks, plus a tail to let echo drain.
+
+    Args:
+        tail_secs: How long to stay muted after playback ends.
+    """
+
+    def __init__(self, *, tail_secs: float = 0.4):
+        super().__init__()
+        self._tail_secs = tail_secs
+        self._bot_speaking = False
+        self._stopped_at = 0.0
+
+    async def process_frame(self, frame: Frame) -> bool:
+        await super().process_frame(frame)
+
+        if isinstance(frame, BotStartedSpeakingFrame):
+            self._bot_speaking = True
+        elif isinstance(frame, BotStoppedSpeakingFrame):
+            self._bot_speaking = False
+            self._stopped_at = time.monotonic()
+
+        if self._bot_speaking:
+            return True
+        return time.monotonic() - self._stopped_at < self._tail_secs