fix: move VAD agent creation to RI communication agent

Previously, it was started in main, but it should use values negotiated by the RI communication agent.

ref: N25B-356

src/control_backend/agents/communication/ri_communication_agent.py

@@ -9,6 +9,7 @@ from control_backend.agents import BaseAgent
 from control_backend.core.config import settings
 
 from ..actuation.robot_speech_agent import RobotSpeechAgent
+from ..perception import VADAgent
 
 
 class RICommunicationAgent(BaseAgent):
@@ -185,6 +186,9 @@ class RICommunicationAgent(BaseAgent):
                         bind=bind,
                     )
                     await ri_commands_agent.start()
+                case "audio":
+                    vad_agent = VADAgent(audio_in_address=addr, audio_in_bind=bind)
+                    await vad_agent.start()
                 case _:
                     self.logger.warning("Unhandled negotiation id: %s", id)
 

src/control_backend/agents/perception/vad_agent.py

@@ -8,6 +8,7 @@ import zmq.asyncio as azmq
 from control_backend.agents import BaseAgent
 from control_backend.core.config import settings
 
+from ...schemas.program_status import PROGRAM_STATUS, ProgramStatus
 from .transcription_agent.transcription_agent import TranscriptionAgent
 
 
@@ -61,6 +62,7 @@ class VADAgent(BaseAgent):
     :ivar audio_in_address: Address of the input audio stream.
     :ivar audio_in_bind: Whether to bind or connect to the input address.
     :ivar audio_out_socket: ZMQ PUB socket for sending speech fragments.
+    :ivar program_sub_socket: ZMQ SUB socket for receiving program status updates.
     """
 
     def __init__(self, audio_in_address: str, audio_in_bind: bool):
@@ -79,6 +81,8 @@ class VADAgent(BaseAgent):
         self.audio_out_socket: azmq.Socket | None = None
         self.audio_in_poller: SocketPoller | None = None
 
+        self.program_sub_socket: azmq.Socket | None = None
+
         self.audio_buffer = np.array([], dtype=np.float32)
         self.i_since_speech = settings.behaviour_settings.vad_initial_since_speech
         self._ready = asyncio.Event()
@@ -90,9 +94,10 @@ class VADAgent(BaseAgent):
 
         1. Connects audio input socket.
         2. Binds audio output socket (random port).
-        3. Loads VAD model from Torch Hub.
+        3. Connects to program communication socket.
-        4. Starts the streaming loop.
+        4. Loads VAD model from Torch Hub.
-        5. Instantiates and starts the :class:`TranscriptionAgent` with the output address.
+        5. Starts the streaming loop.
+        6. Instantiates and starts the :class:`TranscriptionAgent` with the output address.
         """
         self.logger.info("Setting up %s", self.name)
 
@@ -105,6 +110,11 @@ class VADAgent(BaseAgent):
             return
         audio_out_address = f"tcp://localhost:{audio_out_port}"
 
+        # Connect to internal communication socket
+        self.program_sub_socket = azmq.Context.instance().socket(zmq.SUB)
+        self.program_sub_socket.connect(settings.zmq_settings.internal_sub_address)
+        self.program_sub_socket.subscribe(PROGRAM_STATUS)
+
         # Initialize VAD model
         try:
             self.model, _ = torch.hub.load(
@@ -117,10 +127,8 @@ class VADAgent(BaseAgent):
             await self.stop()
             return
 
-        # Warmup/reset
-        await self.reset_stream()
-
         self.add_behavior(self._streaming_loop())
+        self.add_behavior(self._status_loop())
 
         # Start agents dependent on the output audio fragments here
         transcriber = TranscriptionAgent(audio_out_address)
@@ -165,7 +173,7 @@ class VADAgent(BaseAgent):
             self.audio_out_socket = None
             return None
 
-    async def reset_stream(self):
+    async def _reset_stream(self):
         """
         Clears the ZeroMQ queue and sets ready state.
         """
@@ -176,6 +184,23 @@ class VADAgent(BaseAgent):
         self.logger.info(f"Discarded {discarded} audio packets before starting.")
         self._ready.set()
 
+    async def _status_loop(self):
+        """Loop for checking program status. Only start listening if program is RUNNING."""
+        while self._running:
+            topic, body = await self.program_sub_socket.recv_multipart()
+
+            if topic != PROGRAM_STATUS:
+                continue
+            if body != ProgramStatus.RUNNING.value:
+                continue
+
+            # Program is now running, we can start our stream
+            await self._reset_stream()
+
+            # We don't care about further status updates
+            self.program_sub_socket.close()
+            break
+
     async def _streaming_loop(self):
         """
         Main loop for processing audio stream.

src/control_backend/core/config.py

@@ -17,7 +17,6 @@ class ZMQSettings(BaseModel):
     internal_sub_address: str = "tcp://localhost:5561"
     ri_command_address: str = "tcp://localhost:0000"
     ri_communication_address: str = "tcp://*:5555"
-    vad_agent_address: str = "tcp://localhost:5558"
 
 
 class AgentSettings(BaseModel):

src/control_backend/main.py

@@ -39,13 +39,11 @@ from control_backend.agents.communication import RICommunicationAgent
 # LLM Agents
 from control_backend.agents.llm import LLMAgent
 
-# Perceive agents
-from control_backend.agents.perception import VADAgent
-
 # Other backend imports
 from control_backend.api.v1.router import api_router
 from control_backend.core.config import settings
 from control_backend.logging import setup_logging
+from control_backend.schemas.program_status import PROGRAM_STATUS, ProgramStatus
 
 logger = logging.getLogger(__name__)
 
@@ -95,6 +93,8 @@ async def lifespan(app: FastAPI):
     endpoints_pub_socket.connect(settings.zmq_settings.internal_pub_address)
     app.state.endpoints_pub_socket = endpoints_pub_socket
 
+    await endpoints_pub_socket.send_multipart([PROGRAM_STATUS, ProgramStatus.STARTING.value])
+
     # --- Initialize Agents ---
     logger.info("Initializing and starting agents.")
 
@@ -132,10 +132,6 @@ async def lifespan(app: FastAPI):
                 "name": settings.agent_settings.text_belief_extractor_name,
             },
         ),
-        "VADAgent": (
-            VADAgent,
-            {"audio_in_address": settings.zmq_settings.vad_agent_address, "audio_in_bind": False},
-        ),
         "ProgramManagerAgent": (
             BDIProgramManager,
             {
@@ -146,32 +142,28 @@ async def lifespan(app: FastAPI):
 
     agents = []
 
-    vad_agent = None
-
     for name, (agent_class, kwargs) in agents_to_start.items():
         try:
             logger.debug("Starting agent: %s", name)
             agent_instance = agent_class(**kwargs)
             await agent_instance.start()
-            if isinstance(agent_instance, VADAgent):
-                vad_agent = agent_instance
             agents.append(agent_instance)
             logger.info("Agent '%s' started successfully.", name)
         except Exception as e:
             logger.error("Failed to start agent '%s': %s", name, e, exc_info=True)
             raise
 
-    assert vad_agent is not None
-    await vad_agent.reset_stream()
-
     logger.info("Application startup complete.")
 
+    await endpoints_pub_socket.send_multipart([PROGRAM_STATUS, ProgramStatus.RUNNING.value])
+
     yield
 
     # --- APPLICATION SHUTDOWN ---
     logger.info("%s is shutting down.", app.title)
 
-    # Potential shutdown logic goes here
+    await endpoints_pub_socket.send_multipart([PROGRAM_STATUS, ProgramStatus.STOPPING.value])
+    # Additional shutdown logic goes here
 
     logger.info("Application shutdown complete.")
 

src/control_backend/schemas/program_status.py

@@ -0,0 +1,16 @@
+from enum import Enum
+
+PROGRAM_STATUS = b"internal/program_status"
+"""A topic key for the program status."""
+
+
+class ProgramStatus(Enum):
+    """
+    Used in internal communication, to tell agents what the status of the program is.
+
+    For example, the VAD agent only starts listening when the program is RUNNING.
+    """
+
+    STARTING = b"starting"
+    RUNNING = b"running"
+    STOPPING = b"stopping"

test/integration/agents/perception/vad_agent/test_vad_agent.py

@@ -5,6 +5,7 @@ import pytest
 import zmq
 
 from control_backend.agents.perception.vad_agent import VADAgent
+from control_backend.schemas.program_status import PROGRAM_STATUS, ProgramStatus
 
 
 @pytest.fixture
@@ -43,14 +44,12 @@ async def test_normal_setup(per_transcription_agent):
         coro.close()
 
     per_vad_agent.add_behavior = swallow_background_task
-    per_vad_agent.reset_stream = AsyncMock()
 
     await per_vad_agent.setup()
 
     per_transcription_agent.assert_called_once()
     per_transcription_agent.return_value.start.assert_called_once()
     per_vad_agent._streaming_loop.assert_called_once()
-    per_vad_agent.reset_stream.assert_called_once()
     assert per_vad_agent.audio_in_socket is not None
     assert per_vad_agent.audio_out_socket is not None
 
@@ -103,7 +102,7 @@ async def test_out_socket_creation_failure(zmq_context):
     zmq_context.return_value.socket.return_value.bind_to_random_port.side_effect = zmq.ZMQBindError
     per_vad_agent = VADAgent("tcp://localhost:12345", False)
     per_vad_agent.stop = AsyncMock()
-    per_vad_agent.reset_stream = AsyncMock()
+    per_vad_agent._reset_stream = AsyncMock()
     per_vad_agent._streaming_loop = AsyncMock()
     per_vad_agent._connect_audio_out_socket = MagicMock(return_value=None)
 
@@ -124,7 +123,7 @@ async def test_stop(zmq_context, per_transcription_agent):
     Test that when the VAD agent is stopped, the sockets are closed correctly.
     """
     per_vad_agent = VADAgent("tcp://localhost:12345", False)
-    per_vad_agent.reset_stream = AsyncMock()
+    per_vad_agent._reset_stream = AsyncMock()
     per_vad_agent._streaming_loop = AsyncMock()
 
     async def swallow_background_task(coro):
@@ -142,3 +141,66 @@ async def test_stop(zmq_context, per_transcription_agent):
     assert zmq_context.return_value.socket.return_value.close.call_count == 2
     assert per_vad_agent.audio_in_socket is None
     assert per_vad_agent.audio_out_socket is None
+
+
+@pytest.mark.asyncio
+async def test_application_startup_complete(zmq_context):
+    """Check that it resets the stream when the program finishes startup."""
+    vad_agent = VADAgent("tcp://localhost:12345", False)
+    vad_agent._running = True
+    vad_agent._reset_stream = AsyncMock()
+    vad_agent.program_sub_socket = AsyncMock()
+    vad_agent.program_sub_socket.recv_multipart.side_effect = [
+        (PROGRAM_STATUS, ProgramStatus.RUNNING.value),
+    ]
+
+    await vad_agent._status_loop()
+
+    vad_agent._reset_stream.assert_called_once()
+    vad_agent.program_sub_socket.close.assert_called_once()
+
+
+@pytest.mark.asyncio
+async def test_application_other_status(zmq_context):
+    """
+    Check that it does nothing when the internal communication message is a status update, but not
+    running.
+    """
+    vad_agent = VADAgent("tcp://localhost:12345", False)
+    vad_agent._running = True
+    vad_agent._reset_stream = AsyncMock()
+    vad_agent.program_sub_socket = AsyncMock()
+
+    vad_agent.program_sub_socket.recv_multipart.side_effect = [
+        (PROGRAM_STATUS, ProgramStatus.STARTING.value),
+        (PROGRAM_STATUS, ProgramStatus.STOPPING.value),
+    ]
+    try:
+        # Raises StopAsyncIteration the third time it calls `program_sub_socket.recv_multipart`
+        await vad_agent._status_loop()
+    except StopAsyncIteration:
+        pass
+
+    vad_agent._reset_stream.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_application_message_other(zmq_context):
+    """
+    Check that it does nothing when there's an internal communication message that is not a status
+    update.
+    """
+    vad_agent = VADAgent("tcp://localhost:12345", False)
+    vad_agent._running = True
+    vad_agent._reset_stream = AsyncMock()
+    vad_agent.program_sub_socket = AsyncMock()
+
+    vad_agent.program_sub_socket.recv_multipart.side_effect = [(b"internal/other", b"Whatever")]
+
+    try:
+        # Raises StopAsyncIteration the second time it calls `program_sub_socket.recv_multipart`
+        await vad_agent._status_loop()
+    except StopAsyncIteration:
+        pass
+
+    vad_agent._reset_stream.assert_not_called()