backend/lm-livekit-helper.git

			@@ -1,30 +1,53 @@
			mod audio;
			mod service;

			use std::{env, sync::Arc, time::Duration};
			use std::{
			env, fs,
			path::{Path, PathBuf},
			sync::{
			Arc,
			atomic::{AtomicBool, Ordering},
			},
			time::{Duration, Instant, SystemTime, UNIX_EPOCH},
			};

			use anyhow::{Context, Result, anyhow};
			use audio::load_pre_recorded_frames;
			use audio::{AudioDiagnostics, PcmFrame, load_pre_recorded_frames};
			use base64::{Engine as _, engine::general_purpose};
			use futures_util::StreamExt;
			use libwebrtc::{
			audio_source::native::NativeAudioSource,
			audio_stream::native::NativeAudioStream,
			prelude::{AudioFrame, AudioSourceOptions, RtcAudioSource},
			};
			use livekit::{
			options::TrackPublishOptions,
			prelude::{DataPacket, LocalAudioTrack, LocalTrack, ParticipantIdentity, Room, RoomOptions},
			prelude::{
			DataPacket, LocalAudioTrack, LocalTrack, ParticipantIdentity, RemoteAudioTrack,
			RemoteTrack, Room, RoomEvent, RoomOptions,
			},
			};
			use reqwest::Client;
			use serde::Serialize;
			use tokio::time::sleep;
			use serde::{Deserialize, Serialize};
			use serde_json::json;
			use tokio::time::{sleep, sleep_until};
			use tokio::{sync::mpsc::UnboundedReceiver, task::JoinHandle};
			use tracing::{info, warn};

			const TARGET_SAMPLE_RATE_HZ: u32 = 48_000;
			const TARGET_NUM_CHANNELS: u16 = 1;
			const TRACK_NAME: &str = "bot-main-audio";
			const DEVICE_OUTPUT_TOPIC: &str = "device_output";

			#[tokio::main(flavor = "multi_thread")]
			async fn main() -> Result<()> {
			init_tracing();
			if service::service_mode_enabled() {
			return service::run_service().await;
			}
			run_worker().await
			}

			async fn run_worker() -> Result<()> {
			let config = Config::from_env()?;
			let http = Client::builder()
			.use_rustls_tls()
			@@ -37,10 +60,13 @@
			config.greeting_audio_url.as_deref(),
			TARGET_SAMPLE_RATE_HZ,
			TARGET_NUM_CHANNELS,
			config.audio_debug_dump_dir.as_deref(),
			&config.call_id,
			"greeting",
			)
			.await?;

			let (room, _events) = Room::connect(
			let (room, events) = Room::connect(
			config.livekit_url.as_str(),
			config.bot_token.as_str(),
			RoomOptions::default(),
			@@ -52,42 +78,134 @@
			info!(
			call_id = %config.call_id,
			trace_id = %config.trace_id,
			room_id = %config.room_id,
			room_alias = %redact(&config.room_id),
			participant_alias = %redact(&config.bot_participant_identity),
			greeting_source = %config.greeting_source,
			"combrabo voice runtime helper connected"
			);
			emit_activity(
			&config.call_id,
			&config.trace_id,
			None,
			"bot_participant_joined",
			"ok",
			None,
			None,
			json!({"participantAlias": redact(&config.bot_participant_identity)}),
			);

			let vad_enabled_gate = Arc::new(AtomicBool::new(
			!config.simple_vad_enabled \|\| !config.simple_vad_gate_until_greeting_done,
			));
			if config.simple_vad_enabled && config.simple_vad_gate_until_greeting_done {
			info!(
			call_id = %config.call_id,
			trace_id = %config.trace_id,
			post_greeting_delay_ms = config.simple_vad_post_greeting_delay_ms,
			"runtime helper vad_disabled_greeting"
			);
			} else if config.simple_vad_enabled {
			info!(
			call_id = %config.call_id,
			trace_id = %config.trace_id,
			"runtime helper vad_enabled"
			);
			emit_activity(
			&config.call_id,
			&config.trace_id,
			None,
			"vad_enabled",
			"ok",
			None,
			None,
			json!({"reason": "gate_disabled"}),
			);
			}

			let sink = BotAudioOutputSink::publish(
			room.clone(),
			&config.room_id,
			&config.bot_participant_identity,
			&config.call_id,
			&config.trace_id,
			TRACK_NAME,
			TARGET_SAMPLE_RATE_HZ,
			u32::from(TARGET_NUM_CHANNELS),
			config.user_participant_identity.clone(),
			)
			.await?;
			let sink = Arc::new(sink);

			if config.device_output_smoke_enabled {
			publish_device_output_smoke(room.as_ref(), &config).await?;
			}
			let user_audio_observer = spawn_user_audio_observer(
			events,
			&config,
			vad_enabled_gate.clone(),
			http.clone(),
			sink.clone(),
			);

			if let Some(frames) = greeting_frames {
			if let Some(loaded_audio) = greeting_frames {
			let diagnostics = loaded_audio.diagnostics;
			let frames = loaded_audio.frames;
			log_audio_diagnostics(&config, &diagnostics);
			info!(
			call_id = %config.call_id,
			frame_count = frames.len(),
			theoretical_duration_ms = diagnostics.target_duration_ms,
			greeting_source = %config.greeting_source,
			"runtime helper starting greeting playback"
			);
			for frame in &frames {
			emit_activity(
			&config.call_id,
			&config.trace_id,
			None,
			"greeting_write_started",
			"ok",
			None,
			None,
			json!({
			"frameCount": frames.len(),
			"greetingTheoreticalDurationMs": diagnostics.target_duration_ms,
			}),
			);
			let playback_started_at = Instant::now();
			let pacing_started_at = tokio::time::Instant::now();
			for (index, frame) in frames.iter().enumerate() {
			sink.write_pcm_frame(frame).await?;
			sleep(Duration::from_millis(20)).await;
			sleep_until(pacing_started_at + Duration::from_millis(((index + 1) as u64) * 20)).await;
			}
			let playback_wall_ms = playback_started_at.elapsed().as_millis() as i64;
			let drift_ms = playback_wall_ms - diagnostics.target_duration_ms as i64;
			sink.clear_buffer();
			info!(
			call_id = %config.call_id,
			greeting_source = %config.greeting_source,
			frame_count = frames.len(),
			theoretical_duration_ms = diagnostics.target_duration_ms,
			push_wall_duration_ms = playback_wall_ms,
			push_drift_ms = drift_ms,
			"runtime helper finished greeting playback"
			);
			emit_activity(
			&config.call_id,
			&config.trace_id,
			None,
			"greeting_write_finished",
			"ok",
			None,
			None,
			json!({
			"frameCount": frames.len(),
			"greetingTheoreticalDurationMs": diagnostics.target_duration_ms,
			"greetingPushWallDurationMs": playback_wall_ms,
			"greetingPushDriftMs": drift_ms,
			}),
			);
			schedule_vad_gate_enable(
			vad_enabled_gate,
			&config,
			config.simple_vad_post_greeting_delay_ms,
			"greeting_finished",
			);
			} else {
			warn!(
			@@ -95,9 +213,12 @@
			greeting_source = %config.greeting_source,
			"runtime helper started without greeting audio; keeping published track alive"
			);
			schedule_vad_gate_enable(vad_enabled_gate, &config, 0, "no_greeting_audio");
			}

			wait_for_shutdown_signal().await?;
			user_audio_observer.abort();
			let _ = user_audio_observer.await;

			if let Err(error) = sink.close().await {
			warn!(
			@@ -133,12 +254,70 @@
			room_id: String,
			bot_token: String,
			bot_participant_identity: String,
			user_participant_identity: Option<String>,
			greeting_source: String,
			greeting_audio_file: Option<String>,
			greeting_audio_url: Option<String>,
			role_id: String,
			device_output_smoke_enabled: bool,
			device_output_destination_identities: Vec<ParticipantIdentity>,
			audio_debug_dump_dir: Option<String>,
			runtime_turn_bridge_url: Option<String>,
			runtime_turn_bridge_token: Option<String>,
			runtime_turn_bridge_mode: String,
			runtime_turn_artifact_dir: Option<String>,
			runtime_session_nonce: Option<String>,
			user_audio_observer_enabled: bool,
			simple_vad_enabled: bool,
			simple_vad_gate_until_greeting_done: bool,
			simple_vad_post_greeting_delay_ms: u64,
			simple_vad_config: SimpleVadConfig,
			}

			#[derive(Clone)]
			struct TurnBridgeConfig {
			bridge_url: Option<String>,
			bridge_token: Option<String>,
			bridge_mode: String,
			artifact_dir: Option<String>,
			runtime_session_nonce: Option<String>,
			audio_debug_dump_dir: Option<String>,
			}

			impl TurnBridgeConfig {
			fn from_config(config: &Config) -> Self {
			Self {
			bridge_url: config.runtime_turn_bridge_url.clone(),
			bridge_token: config.runtime_turn_bridge_token.clone(),
			bridge_mode: config.runtime_turn_bridge_mode.clone(),
			artifact_dir: config.runtime_turn_artifact_dir.clone(),
			runtime_session_nonce: config.runtime_session_nonce.clone(),
			audio_debug_dump_dir: config.audio_debug_dump_dir.clone(),
			}
			}

			fn is_ready(&self) -> bool {
			self.bridge_url
			.as_ref()
			.is_some_and(\|value\| !value.is_empty())
			&& self
			.bridge_token
			.as_ref()
			.is_some_and(\|value\| !value.is_empty())
			&& self
			.artifact_dir
			.as_ref()
			.is_some_and(\|value\| !value.is_empty())
			&& self
			.runtime_session_nonce
			.as_ref()
			.is_some_and(\|value\| !value.is_empty())
			}

			fn is_stream_mode(&self) -> bool {
			self.bridge_mode.eq_ignore_ascii_case("stream")
			\|\| self
			.bridge_url
			.as_deref()
			.is_some_and(\|value\| value.trim_end_matches('/').ends_with("/stream"))
			}
			}

			impl Config {
			@@ -150,18 +329,115 @@
			room_id: required_env("CV_LIVEKIT_ROOM_ID")?,
			bot_token: required_env("CV_LIVEKIT_BOT_TOKEN")?,
			bot_participant_identity: required_env("CV_LIVEKIT_BOT_PARTICIPANT_IDENTITY")?,
			user_participant_identity: optional_env("CV_LIVEKIT_USER_PARTICIPANT_IDENTITY"),
			greeting_source: env::var("CV_GREETING_SOURCE")
			.unwrap_or_else(\|_\| "no_audio".to_string()),
			greeting_audio_file: optional_env("CV_GREETING_AUDIO_FILE"),
			greeting_audio_url: optional_env("CV_GREETING_AUDIO_URL"),
			role_id: env::var("CV_ROLE_ID").unwrap_or_else(\|_\| "90".to_string()),
			device_output_smoke_enabled: bool_env("CV_DEVICE_OUTPUT_SMOKE_ENABLED"),
			device_output_destination_identities: device_output_destinations(
			optional_env("CV_DEVICE_OUTPUT_DESTINATION_IDENTITIES"),
			optional_env("CV_LIVEKIT_USER_PARTICIPANT_IDENTITY"),
			),
			audio_debug_dump_dir: optional_env("CV_AUDIO_DEBUG_DUMP_DIR"),
			runtime_turn_bridge_url: optional_env("CV_RUNTIME_TURN_BRIDGE_URL"),
			runtime_turn_bridge_token: optional_env("CV_RUNTIME_TURN_BRIDGE_TOKEN"),
			runtime_turn_bridge_mode: env::var("CV_RUNTIME_TURN_BRIDGE_MODE")
			.unwrap_or_else(\|_\| "json".to_string()),
			runtime_turn_artifact_dir: optional_env("CV_RUNTIME_TURN_ARTIFACT_DIR"),
			runtime_session_nonce: optional_env("CV_RUNTIME_SESSION_NONCE"),
			user_audio_observer_enabled: bool_env("CV_ENABLE_USER_AUDIO_OBSERVER", true),
			simple_vad_enabled: bool_env("CV_ENABLE_SIMPLE_VAD", true),
			simple_vad_gate_until_greeting_done: bool_env("CV_VAD_GATE_UNTIL_GREETING_DONE", true),
			simple_vad_post_greeting_delay_ms: u64_env("CV_VAD_POST_GREETING_DELAY_MS", 800),
			simple_vad_config: SimpleVadConfig::from_env(),
			})
			}
			}

			fn schedule_vad_gate_enable(
			gate: Arc<AtomicBool>,
			config: &Config,
			delay_ms: u64,
			reason: &'static str,
			) {
			if !config.simple_vad_enabled \|\| !config.simple_vad_gate_until_greeting_done {
			return;
			}

			let call_id = config.call_id.clone();
			let trace_id = config.trace_id.clone();
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			delay_ms,
			reason,
			"runtime helper vad_enable_scheduled"
			);
			emit_activity(
			&call_id,
			&trace_id,
			None,
			"vad_enable_scheduled",
			"ok",
			None,
			None,
			json!({
			"vadEnableDelayMs": delay_ms,
			"reason": reason,
			}),
			);

			tokio::spawn(async move {
			if delay_ms > 0 {
			sleep(Duration::from_millis(delay_ms)).await;
			}
			gate.store(true, Ordering::Release);
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			delay_ms,
			reason,
			"runtime helper vad_enabled"
			);
			emit_activity(
			&call_id,
			&trace_id,
			None,
			"vad_enabled",
			"ok",
			None,
			None,
			json!({
			"vadEnableDelayMs": delay_ms,
			"reason": reason,
			}),
			);
			});
			}

			fn log_audio_diagnostics(config: &Config, diagnostics: &AudioDiagnostics) {
			info!(
			call_id = %config.call_id,
			trace_id = %config.trace_id,
			greeting_source = %config.greeting_source,
			source_kind = diagnostics.source_kind,
			source_format = diagnostics.source_format,
			source_bytes = diagnostics.source_bytes,
			source_sample_rate_hz = diagnostics.source_sample_rate_hz,
			source_num_channels = diagnostics.source_num_channels,
			decoded_sample_count = diagnostics.decoded_sample_count,
			decoded_duration_ms = diagnostics.decoded_duration_ms,
			target_sample_rate_hz = diagnostics.target_sample_rate_hz,
			target_num_channels = diagnostics.target_num_channels,
			target_sample_count = diagnostics.target_sample_count,
			target_duration_ms = diagnostics.target_duration_ms,
			frame_count = diagnostics.frame_count,
			rms = diagnostics.rms,
			peak = diagnostics.peak,
			clipped_sample_count = diagnostics.clipped_sample_count,
			silence_ratio = diagnostics.silence_ratio,
			mp3_skipped_data_count = diagnostics.mp3_skipped_data_count,
			mp3_insufficient_data_count = diagnostics.mp3_insufficient_data_count,
			debug_source_path = diagnostics.debug_source_path.as_deref().unwrap_or(""),
			debug_pcm_wav_path = diagnostics.debug_pcm_wav_path.as_deref().unwrap_or(""),
			"runtime helper greeting audio quality diagnostics"
			);
			}

			fn required_env(key: &str) -> Result<String> {
			@@ -183,34 +459,37 @@
			})
			}

			fn bool_env(key: &str) -> bool {
			matches!(
			env::var(key)
			.unwrap_or_default()
			.trim()
			.to_ascii_lowercase()
			.as_str(),
			"1" \| "true" \| "yes" \| "y" \| "on"
			)
			fn bool_env(key: &str, default_value: bool) -> bool {
			match env::var(key) {
			Ok(value) => match value.trim().to_ascii_lowercase().as_str() {
			"1" \| "true" \| "yes" \| "on" => true,
			"0" \| "false" \| "no" \| "off" => false,
			_ => default_value,
			},
			Err(_) => default_value,
			}
			}

			fn device_output_destinations(
			configured: Option<String>,
			user_identity: Option<String>,
			) -> Vec<ParticipantIdentity> {
			let identities = configured
			.filter(\|value\| !value.trim().is_empty())
			.map(\|value\| {
			value
			.split(',')
			.map(str::trim)
			.filter(\|identity\| !identity.is_empty())
			.map(ToOwned::to_owned)
			.collect::<Vec<_>>()
			})
			.or_else(\|\| user_identity.map(\|identity\| vec![identity]))
			.unwrap_or_default();
			identities.into_iter().map(Into::into).collect()
			fn f64_env(key: &str, default_value: f64) -> f64 {
			env::var(key)
			.ok()
			.and_then(\|value\| value.trim().parse::<f64>().ok())
			.filter(\|value\| value.is_finite() && *value >= 0.0)
			.unwrap_or(default_value)
			}

			fn u64_env(key: &str, default_value: u64) -> u64 {
			env::var(key)
			.ok()
			.and_then(\|value\| value.trim().parse::<u64>().ok())
			.unwrap_or(default_value)
			}

			fn u32_env(key: &str, default_value: u32) -> u32 {
			env::var(key)
			.ok()
			.and_then(\|value\| value.trim().parse::<u32>().ok())
			.unwrap_or(default_value)
			}

			fn redact(value: &str) -> String {
			@@ -220,118 +499,2108 @@
			format!("{}***{}", &value[..4], &value[value.len() - 4..])
			}

			#[derive(Serialize)]
			struct DeviceOutputMessage {
			#[serde(rename = "type")]
			message_type: &'static str,
			#[serde(rename = "schemaVersion")]
			schema_version: &'static str,
			#[serde(rename = "callId")]
			fn safe_error(value: &str) -> String {
			let sanitized = value.replace(['\r', '\n'], " ");
			let trimmed = sanitized.trim();
			let mut output: String = trimmed.chars().take(180).collect();
			if trimmed.chars().count() > 180 {
			output.push_str("...");
			}
			output
			}

			fn current_time_millis() -> u64 {
			SystemTime::now()
			.duration_since(UNIX_EPOCH)
			.map(\|value\| value.as_millis() as u64)
			.unwrap_or_default()
			}

			fn emit_activity(
			call_id: &str,
			trace_id: &str,
			turn_id: Option<&str>,
			event_name: &str,
			result: &str,
			reason_code: Option<&str>,
			retryable: Option<bool>,
			extension: serde_json::Value,
			) {
			let payload = json!({
			"type": "cv_activity",
			"callId": call_id,
			"traceId": trace_id,
			"turnId": turn_id,
			"eventName": event_name,
			"result": result,
			"reasonCode": reason_code,
			"retryable": retryable,
			"extension": extension,
			});
			println!("{payload}");
			}

			fn spawn_user_audio_observer(
			events: UnboundedReceiver<RoomEvent>,
			config: &Config,
			vad_enabled_gate: Arc<AtomicBool>,
			http: Client,
			sink: Arc<BotAudioOutputSink>,
			) -> JoinHandle<()> {
			let call_id = config.call_id.clone();
			let trace_id = config.trace_id.clone();
			let enabled = config.user_audio_observer_enabled;
			let simple_vad_enabled = config.simple_vad_enabled;
			let simple_vad_config = config.simple_vad_config.clone();
			let turn_bridge_config = TurnBridgeConfig::from_config(config);

			tokio::spawn(async move {
			if !enabled {
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			"runtime helper user audio observer disabled"
			);
			return;
			}
			observe_user_audio_events(
			events,
			call_id,
			trace_id,
			simple_vad_enabled,
			simple_vad_config,
			vad_enabled_gate,
			turn_bridge_config,
			http,
			sink,
			)
			.await;
			})
			}

			async fn observe_user_audio_events(
			mut events: UnboundedReceiver<RoomEvent>,
			call_id: String,
			#[serde(rename = "roleId")]
			role_id: String,
			#[serde(rename = "traceId")]
			trace_id: String,
			#[serde(rename = "ackMode")]
			ack_mode: &'static str,
			#[serde(rename = "sensorInstructions")]
			sensor_instructions: Vec<SensorInstruction>,
			simple_vad_enabled: bool,
			simple_vad_config: SimpleVadConfig,
			vad_enabled_gate: Arc<AtomicBool>,
			turn_bridge_config: TurnBridgeConfig,
			http: Client,
			sink: Arc<BotAudioOutputSink>,
			) {
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			simple_vad_enabled,
			vad_rms_threshold = simple_vad_config.rms_threshold,
			vad_peak_threshold = simple_vad_config.peak_threshold,
			vad_start_frames = simple_vad_config.start_frames,
			vad_end_silence_ms = simple_vad_config.end_silence_ms,
			vad_min_speech_ms = simple_vad_config.min_speech_ms,
			vad_max_turn_ms = simple_vad_config.max_turn_ms,
			vad_initial_ignore_ms = simple_vad_config.initial_ignore_ms,
			vad_gate_enabled = vad_enabled_gate.load(Ordering::Acquire),
			"runtime helper user_track_subscribe_requested"
			);

			while let Some(event) = events.recv().await {
			match event {
			RoomEvent::TrackSubscribed {
			track: RemoteTrack::Audio(track),
			publication: _,
			participant,
			} => {
			let participant_alias = redact(&participant.identity().to_string());
			let track_sid_alias = redact(&track.sid().to_string());
			let track_name = track.name();
			let track_source = format!("{:?}", track.source());
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			participant_alias = %participant_alias,
			track_sid_alias = %track_sid_alias,
			track_name = %track_name,
			track_source = %track_source,
			"runtime helper user_track_subscribed"
			);
			spawn_user_audio_frame_observer(
			track,
			call_id.clone(),
			trace_id.clone(),
			participant_alias,
			track_sid_alias,
			simple_vad_enabled,
			simple_vad_config.clone(),
			vad_enabled_gate.clone(),
			turn_bridge_config.clone(),
			http.clone(),
			sink.clone(),
			);
			}
			RoomEvent::TrackSubscribed {
			track: RemoteTrack::Video(track),
			publication: _,
			participant,
			} => {
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			participant_alias = %redact(&participant.identity().to_string()),
			track_sid_alias = %redact(&track.sid().to_string()),
			"runtime helper ignored non-audio subscribed track"
			);
			}
			RoomEvent::TrackSubscriptionFailed {
			participant,
			error,
			track_sid,
			} => {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			participant_alias = %redact(&participant.identity().to_string()),
			track_sid_alias = %redact(&track_sid.to_string()),
			error = %error,
			"runtime helper user_track_subscription_failed"
			);
			}
			RoomEvent::Disconnected { reason } => {
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			reason = ?reason,
			"runtime helper room event stream disconnected"
			);
			break;
			}
			_ => {}
			}
			}
			}

			#[derive(Serialize)]
			struct SensorInstruction {
			#[serde(rename = "commandId")]
			command_id: String,
			#[serde(rename = "sensorType")]
			sensor_type: &'static str,
			#[serde(rename = "operationType")]
			operation_type: &'static str,
			step: i32,
			#[serde(rename = "durationSec", skip_serializing_if = "Option::is_none")]
			duration_sec: Option<i32>,
			extension: String,
			async fn handle_finished_turn(
			http: &Client,
			bridge_config: &TurnBridgeConfig,
			sink: &BotAudioOutputSink,
			call_id: &str,
			trace_id: &str,
			turn: FinishedSpeechTurn,
			) {
			let turn_pipeline_started_at = Instant::now();
			if !bridge_config.is_ready() {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			turn_index = turn.turn_index,
			duration_ms = turn.duration_ms,
			"runtime helper turn_bridge_skipped"
			);
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"turn_bridge_skipped",
			"skipped",
			Some("TURN_BRIDGE_NOT_CONFIGURED"),
			Some(true),
			json!({
			"durationMs": turn.duration_ms,
			"frameCount": turn.frame_count,
			"sampleCount": turn.sample_count,
			}),
			);
			return;
			}

			let artifact_root = PathBuf::from(bridge_config.artifact_dir.as_deref().unwrap_or_default());
			match write_user_turn_artifact(&artifact_root, call_id, &turn) {
			Ok((path_ref, byte_size)) => {
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			turn_index = turn.turn_index,
			duration_ms = turn.duration_ms,
			frame_count = turn.frame_count,
			sample_count = turn.sample_count,
			byte_size,
			end_reason = %turn.end_reason,
			"runtime helper turn_artifact_written"
			);
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"turn_bridge_requested",
			"ok",
			None,
			None,
			json!({
			"turnDurationMs": turn.duration_ms,
			"turnArtifactBytes": byte_size,
			"frameCount": turn.frame_count,
			"sampleCount": turn.sample_count,
			"endReason": turn.end_reason,
			}),
			);
			if bridge_config.is_stream_mode() {
			match request_turn_bridge_stream(
			http,
			bridge_config,
			sink,
			call_id,
			trace_id,
			&turn,
			&path_ref,
			byte_size,
			turn_pipeline_started_at,
			)
			.await
			{
			Ok(outcome) => {
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			audio_chunk_count = outcome.audio_chunk_count,
			device_output_count = outcome.device_output_count,
			"runtime helper turn_stream_completed"
			);
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"turn_completed",
			"ok",
			None,
			None,
			json!({
			"replyTotalAfterVadEndMs": turn_pipeline_started_at.elapsed().as_millis() as u64,
			"audioChunkCount": outcome.audio_chunk_count,
			"deviceOutputCount": outcome.device_output_count,
			"replyPlaybackMode": outcome.reply_playback_mode,
			}),
			);
			}
			Err(error) => {
			let safe = safe_error(&error.to_string());
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			error = %safe,
			"runtime helper turn_stream_failed"
			);
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"turn_failed",
			"failed",
			Some("TURN_STREAM_FAILED"),
			Some(true),
			json!({
			"stage": "turn_bridge_stream",
			"error": safe,
			}),
			);
			}
			}
			return;
			}
			match request_turn_bridge(
			http,
			bridge_config,
			call_id,
			trace_id,
			&turn,
			&path_ref,
			byte_size,
			turn_pipeline_started_at,
			)
			.await
			{
			Ok(outcome) => {
			for output in &outcome.device_outputs {
			if let Err(error) = sink
			.publish_device_output(call_id, trace_id, &turn.turn_id, output)
			.await
			{
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			reason_code = "BOT_DATA_WRITE_FAILED",
			error = %safe_error(&error.to_string()),
			"runtime helper device_output_failed"
			);
			}
			}
			let Some(reply_audio_artifact) = outcome.reply_audio_artifact else {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			reason_code = "REPLY_AUDIO_MISSING",
			"runtime helper turn_failed"
			);
			return;
			};
			if let Err(error) = write_reply_audio_artifact(
			http,
			bridge_config,
			sink,
			call_id,
			trace_id,
			&turn,
			&reply_audio_artifact,
			turn_pipeline_started_at,
			)
			.await
			{
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			reason_code = "BOT_AUDIO_WRITE_FAILED",
			error = %safe_error(&error.to_string()),
			"runtime helper turn_failed"
			);
			return;
			}
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			"runtime helper turn_completed"
			);
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"turn_completed",
			"ok",
			None,
			None,
			json!({
			"replyTotalAfterVadEndMs": turn_pipeline_started_at.elapsed().as_millis() as u64,
			}),
			);
			}
			Err(error) => warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			error = %safe_error(&error.to_string()),
			"runtime helper turn_bridge_failed"
			),
			}
			}
			Err(error) => warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			error = %safe_error(&error.to_string()),
			"runtime helper turn_artifact_write_failed"
			),
			}
			}

			async fn publish_device_output_smoke(room: &Room, config: &Config) -> Result<()> {
			let payload = build_device_output_smoke_payload(config);
			let payload_json =
			serde_json::to_vec(&payload).context("failed to serialize device output smoke payload")?;
			let destination_count = config.device_output_destination_identities.len();
			room.local_participant()
			.publish_data(DataPacket {
			reliable: true,
			payload: payload_json,
			topic: Some(DEVICE_OUTPUT_TOPIC.to_string()),
			destination_identities: config.device_output_destination_identities.clone(),
			})
			fn write_user_turn_artifact(
			artifact_root: &Path,
			call_id: &str,
			turn: &FinishedSpeechTurn,
			) -> Result<(String, u64)> {
			require_safe_segment(call_id)?;
			require_safe_segment(&turn.turn_id)?;
			if turn.samples.is_empty() {
			return Err(anyhow!("empty turn samples"));
			}
			let path_ref = format!("{}/{}/user.wav", call_id, turn.turn_id);
			let output_path = normalize_path_lexically(&artifact_root.join(&path_ref));
			let root = normalize_path_lexically(artifact_root);
			if !output_path.starts_with(&root) {
			return Err(anyhow!("turn artifact path escapes root"));
			}
			if let Some(parent) = output_path.parent() {
			fs::create_dir_all(parent).context("failed to create turn artifact dir")?;
			}
			audio::write_pcm_wav(
			&output_path,
			&turn.samples,
			TARGET_SAMPLE_RATE_HZ,
			TARGET_NUM_CHANNELS,
			)?;
			let byte_size = fs::metadata(&output_path)
			.context("failed to stat turn artifact")?
			.len();
			Ok((path_ref, byte_size))
			}

			async fn request_turn_bridge_stream(
			http: &Client,
			bridge_config: &TurnBridgeConfig,
			sink: &BotAudioOutputSink,
			call_id: &str,
			trace_id: &str,
			turn: &FinishedSpeechTurn,
			path_ref: &str,
			byte_size: u64,
			turn_pipeline_started_at: Instant,
			) -> Result<RuntimeTurnStreamOutcome> {
			let bridge_started_at = Instant::now();
			let request = RuntimeTurnRequest {
			call_id: call_id.to_string(),
			trace_id: trace_id.to_string(),
			turn_id: turn.turn_id.clone(),
			audio_artifact: RuntimeTurnAudioArtifact {
			artifact_type: "local_file".to_string(),
			path_ref: path_ref.to_string(),
			format: "wav".to_string(),
			sample_rate: TARGET_SAMPLE_RATE_HZ,
			channels: u32::from(TARGET_NUM_CHANNELS),
			duration_ms: turn.duration_ms,
			byte_size,
			},
			};
			let response = http
			.post(bridge_config.bridge_url.as_deref().unwrap_or_default())
			.header(
			"X-CV-Runtime-Token",
			bridge_config.bridge_token.as_deref().unwrap_or_default(),
			)
			.header("X-CV-Call-Id", call_id)
			.header("X-CV-Trace-Id", trace_id)
			.header(
			"X-CV-Runtime-Session-Nonce",
			bridge_config
			.runtime_session_nonce
			.as_deref()
			.unwrap_or_default(),
			)
			.json(&request)
			.send()
			.await
			.map_err(\|error\| anyhow!("failed to publish livekit device output data: {error}"))?;
			.context("failed to post turn stream bridge")?;
			let status = response.status();
			if !status.is_success() {
			let body_len = response.text().await.map(\|body\| body.len()).unwrap_or(0);
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			http_status = status.as_u16(),
			body_len,
			"runtime helper turn_stream_http_failed"
			);
			return Err(anyhow!("turn stream bridge http failed"));
			}

			info!(
			call_id = %config.call_id,
			trace_id = %config.trace_id,
			topic = DEVICE_OUTPUT_TOPIC,
			reliable = true,
			command_count = payload.sensor_instructions.len(),
			destination_count,
			"runtime helper published device output smoke data"
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			"runtime helper turn_stream_connected"
			);
			let mut byte_stream = response.bytes_stream();
			let mut line_buffer: Vec<u8> = Vec::new();
			let mut state = RuntimeTurnStreamState::default();
			while let Some(chunk) = byte_stream.next().await {
			let chunk = chunk.context("failed to read turn stream chunk")?;
			line_buffer.extend_from_slice(&chunk);
			while let Some(newline_index) = line_buffer.iter().position(\|value\| *value == b'\n') {
			let line: Vec<u8> = line_buffer.drain(..=newline_index).collect();
			if let Some(event) = parse_turn_stream_event_line(&line)? {
			handle_turn_stream_event(
			bridge_config,
			sink,
			call_id,
			trace_id,
			turn,
			event,
			&mut state,
			turn_pipeline_started_at,
			)
			.await?;
			}
			}
			}
			if !line_buffer.is_empty() {
			if let Some(event) = parse_turn_stream_event_line(&line_buffer)? {
			handle_turn_stream_event(
			bridge_config,
			sink,
			call_id,
			trace_id,
			turn,
			event,
			&mut state,
			turn_pipeline_started_at,
			)
			.await?;
			}
			}
			if !state.completed {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			audio_chunk_count = state.audio_chunk_count,
			"runtime helper turn_stream_completed_without_final_event"
			);
			return Err(anyhow!("turn stream ended without turn_completed"));
			}
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"turn_bridge_completed",
			"ok",
			None,
			None,
			json!({
			"bridgeWallDurationMs": bridge_started_at.elapsed().as_millis() as u64,
			"replyTotalAfterVadEndMs": turn_pipeline_started_at.elapsed().as_millis() as u64,
			"audioChunkCount": state.audio_chunk_count,
			"deviceOutputCount": state.device_output_count,
			"replyPlaybackMode": state.reply_playback_mode.as_str(),
			}),
			);
			Ok(RuntimeTurnStreamOutcome {
			reply_playback_mode: state.reply_playback_mode,
			audio_chunk_count: state.audio_chunk_count,
			device_output_count: state.device_output_count,
			})
			}

			fn parse_turn_stream_event_line(line: &[u8]) -> Result<Option<RuntimeTurnStreamEvent>> {
			let line = trim_ascii_whitespace(line);
			if line.is_empty() {
			return Ok(None);
			}
			serde_json::from_slice(line)
			.context("failed to parse turn stream event")
			.map(Some)
			}

			fn diagnostic_str<'a>(diagnostics: Option<&'a serde_json::Value>, key: &str) -> Option<&'a str> {
			diagnostics?.get(key)?.as_str()
			}

			fn diagnostic_bool(diagnostics: Option<&serde_json::Value>, key: &str) -> Option<bool> {
			diagnostics?.get(key)?.as_bool()
			}

			fn diagnostic_u64(diagnostics: Option<&serde_json::Value>, key: &str) -> Option<u64> {
			diagnostics?.get(key)?.as_u64()
			}

			async fn handle_turn_stream_event(
			bridge_config: &TurnBridgeConfig,
			sink: &BotAudioOutputSink,
			call_id: &str,
			trace_id: &str,
			turn: &FinishedSpeechTurn,
			event: RuntimeTurnStreamEvent,
			state: &mut RuntimeTurnStreamState,
			turn_pipeline_started_at: Instant,
			) -> Result<()> {
			let event_type = event.event_type();
			match event_type.as_deref() {
			Some("reply_playback_mode_selected") => {
			if let Some(reply_playback_mode) = event.reply_playback_mode.as_deref() {
			state.reply_playback_mode = reply_playback_mode.to_string();
			}
			let diagnostics = event.diagnostics.as_ref();
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			reply_playback_mode = %state.reply_playback_mode,
			streaming_enabled = ?diagnostic_bool(diagnostics, "streamingEnabled"),
			provider_streaming_supported = ?diagnostic_bool(diagnostics, "providerStreamingSupported"),
			first_chunk_received = ?diagnostic_bool(diagnostics, "firstChunkReceived"),
			stream_chunk_count = ?diagnostic_u64(diagnostics, "streamChunkCount"),
			fallback_reason = %diagnostic_str(diagnostics, "fallbackReason").unwrap_or("none"),
			fallback_stage = %diagnostic_str(diagnostics, "fallbackStage").unwrap_or("none"),
			stream_bridge_mode = %diagnostic_str(diagnostics, "streamBridgeMode").unwrap_or("unknown"),
			tts_provider = %diagnostic_str(diagnostics, "ttsProvider").unwrap_or("unknown"),
			"runtime helper reply_playback_mode_selected"
			);
			}
			Some("reply_state") => {
			if let Some(reply_state) = event.state.as_deref() {
			publish_reply_state_from_stream_event(
			sink,
			call_id,
			trace_id,
			&turn.turn_id,
			&state.reply_playback_mode,
			reply_state,
			event.seq,
			)
			.await?;
			if reply_state == "reply_playback_started" {
			state.playback_started_sent = true;
			}
			}
			}
			Some("reply_audio_chunk") => {
			let audio_chunk = event
			.audio_chunk
			.as_ref()
			.ok_or_else(\|\| anyhow!("reply_audio_chunk event missing audioChunk"))?;
			if !state.playback_started_sent {
			state.reply_state_seq = state.reply_state_seq.saturating_add(1);
			sink.publish_reply_state(
			call_id,
			trace_id,
			&turn.turn_id,
			&state.reply_playback_mode,
			"reply_playback_started",
			state.reply_state_seq,
			)
			.await?;
			state.playback_started_sent = true;
			}
			let written_frames = write_stream_audio_chunk(
			bridge_config,
			sink,
			call_id,
			trace_id,
			turn,
			audio_chunk,
			state,
			turn_pipeline_started_at,
			)
			.await?;
			if written_frames > 0 {
			state.audio_chunk_count = state.audio_chunk_count.saturating_add(1);
			}
			}
			Some("device_output") => {
			if let Some(output) = event.device_output.as_ref() {
			sink.publish_device_output(call_id, trace_id, &turn.turn_id, output)
			.await?;
			state.device_output_count = state.device_output_count.saturating_add(1);
			}
			}
			Some("turn_completed") => {
			state.completed = true;
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			message_id_alias = %event.completion.as_ref().and_then(\|value\| value.message_id.as_deref()).map(redact).unwrap_or_else(\|\| "none".to_string()),
			audio_chunk_count = state.audio_chunk_count,
			"runtime helper turn_stream_final_received"
			);
			}
			Some("turn_failed") => {
			let error = event.error.as_ref();
			let reason_code = error
			.and_then(\|value\| value.reason_code.as_deref())
			.unwrap_or("TURN_STREAM_FAILED");
			let stage = error
			.and_then(\|value\| value.stage.as_deref())
			.unwrap_or("turn_bridge_stream");
			let retryable = error.and_then(\|value\| value.retryable).unwrap_or(false);
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			reason_code = %reason_code,
			stage = %stage,
			retryable = retryable,
			"runtime helper turn_stream_failed_event"
			);
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"turn_failed",
			"failed",
			Some(reason_code),
			Some(retryable),
			json!({
			"stage": stage,
			"replyPlaybackMode": state.reply_playback_mode.as_str(),
			}),
			);
			return Err(anyhow!("turn stream failed event"));
			}
			Some("turn_cancelled") => {
			state.completed = true;
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			"runtime helper turn_stream_cancelled_event"
			);
			publish_reply_state_from_stream_event(
			sink,
			call_id,
			trace_id,
			&turn.turn_id,
			&state.reply_playback_mode,
			"reply_playback_cancelled",
			event.seq,
			)
			.await?;
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"turn_cancelled",
			"ok",
			None,
			Some(false),
			json!({
			"replyPlaybackMode": state.reply_playback_mode.as_str(),
			"audioChunkCount": state.audio_chunk_count,
			}),
			);
			}
			Some("activity") => {
			if let Some(activity) = event.activity.as_ref() {
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			activity_event = %activity.event_type.as_deref().unwrap_or("unknown"),
			stage = %activity.stage.as_deref().unwrap_or("unknown"),
			reason_code = %activity.reason_code.as_deref().unwrap_or("none"),
			"runtime helper turn_stream_activity"
			);
			}
			}
			Some(other) => {
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			event_type = %other,
			"runtime helper ignored turn stream event"
			);
			}
			None => {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			"runtime helper ignored turn stream event without type"
			);
			}
			}
			Ok(())
			}

			async fn publish_reply_state_from_stream_event(
			sink: &BotAudioOutputSink,
			call_id: &str,
			trace_id: &str,
			turn_id: &str,
			reply_playback_mode: &str,
			state: &str,
			seq: Option<u64>,
			) -> Result<()> {
			sink.publish_reply_state(
			call_id,
			trace_id,
			turn_id,
			reply_playback_mode,
			state,
			seq.unwrap_or(0),
			)
			.await
			}

			async fn write_stream_audio_chunk(
			bridge_config: &TurnBridgeConfig,
			sink: &BotAudioOutputSink,
			call_id: &str,
			trace_id: &str,
			turn: &FinishedSpeechTurn,
			audio_chunk: &RuntimeTurnStreamAudioChunk,
			state: &mut RuntimeTurnStreamState,
			turn_pipeline_started_at: Instant,
			) -> Result<usize> {
			let payload_base64 = audio_chunk
			.payload_base64
			.as_deref()
			.map(str::trim)
			.filter(\|value\| !value.is_empty())
			.ok_or_else(\|\| anyhow!("reply_audio_chunk payloadBase64 missing"))?;
			let payload = general_purpose::STANDARD
			.decode(payload_base64)
			.context("failed to decode reply_audio_chunk payloadBase64")?;
			let format = audio_chunk
			.format
			.as_deref()
			.unwrap_or("pcm_s16le")
			.trim()
			.to_ascii_lowercase();
			let frames = if format == "pcm_s16le" {
			let frame_alignment_bytes = pcm_s16le_frame_alignment_bytes(
			audio_chunk
			.channels
			.unwrap_or(u32::from(TARGET_NUM_CHANNELS)),
			)?;
			let (aligned_payload, dropped_tail_bytes) = take_aligned_pcm_payload(
			&mut state.pcm_audio_buffer,
			&payload,
			frame_alignment_bytes,
			audio_chunk.last.unwrap_or(false),
			);
			if dropped_tail_bytes > 0 {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			chunk_seq = audio_chunk.chunk_seq.unwrap_or_default(),
			dropped_tail_bytes,
			"runtime helper stream_audio_pcm_unaligned_tail_dropped"
			);
			}
			if aligned_payload.is_empty() {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			chunk_seq = audio_chunk.chunk_seq.unwrap_or_default(),
			buffered_bytes = state.pcm_audio_buffer.len(),
			"runtime helper stream_audio_pcm_waiting_for_sample_boundary"
			);
			return Ok(0);
			}
			pcm_s16le_payload_to_frames(
			&aligned_payload,
			audio_chunk.sample_rate.unwrap_or(TARGET_SAMPLE_RATE_HZ),
			audio_chunk
			.channels
			.unwrap_or(u32::from(TARGET_NUM_CHANNELS)),
			)?
			} else if matches!(format.as_str(), "mp3" \| "mpeg" \| "wav") {
			state.encoded_audio_buffer.extend_from_slice(&payload);
			match audio::decode_audio_bytes_to_frames(
			&state.encoded_audio_buffer,
			"stream_chunk",
			TARGET_SAMPLE_RATE_HZ,
			TARGET_NUM_CHANNELS,
			bridge_config.audio_debug_dump_dir.as_deref(),
			call_id,
			&format!("stream-reply-{}", turn.turn_id),
			) {
			Ok(loaded) => {
			state.encoded_audio_buffer.clear();
			loaded.frames
			}
			Err(error) if !audio_chunk.last.unwrap_or(false) => {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			chunk_seq = audio_chunk.chunk_seq.unwrap_or_default(),
			format = %format,
			error = %safe_error(&error.to_string()),
			"runtime helper stream_audio_chunk_decode_waiting_for_more_data"
			);
			return Ok(0);
			}
			Err(error) if state.first_audio_frame_written => {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			chunk_seq = audio_chunk.chunk_seq.unwrap_or_default(),
			format = %format,
			buffered_bytes = state.encoded_audio_buffer.len(),
			error = %safe_error(&error.to_string()),
			"runtime helper stream_audio_final_chunk_decode_ignored"
			);
			state.encoded_audio_buffer.clear();
			return Ok(0);
			}
			Err(error) => return Err(error).context("failed to decode final stream audio chunk"),
			}
			} else {
			return Err(anyhow!("unsupported reply_audio_chunk format {format}"));
			};
			if frames.is_empty() {
			return Ok(0);
			}

			if !state.first_audio_frame_written {
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"bot_reply_audio_write_started",
			"ok",
			None,
			None,
			json!({
			"replyPlaybackMode": state.reply_playback_mode.as_str(),
			"format": format.as_str(),
			"chunkSeq": audio_chunk.chunk_seq,
			"replyTotalAfterVadEndMs": turn_pipeline_started_at.elapsed().as_millis() as u64,
			}),
			);
			}
			let pacing_started_at = tokio::time::Instant::now();
			for (index, frame) in frames.iter().enumerate() {
			sink.write_pcm_frame(frame).await?;
			if !state.first_audio_frame_written {
			state.first_audio_frame_written = true;
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"bot_reply_first_audio_frame_written",
			"ok",
			None,
			None,
			json!({
			"replyPlaybackMode": state.reply_playback_mode.as_str(),
			"format": format.as_str(),
			"chunkSeq": audio_chunk.chunk_seq,
			"replyTotalAfterVadEndMs": turn_pipeline_started_at.elapsed().as_millis() as u64,
			}),
			);
			}
			sleep_until(pacing_started_at + Duration::from_millis(((index + 1) as u64) * 20)).await;
			}
			if audio_chunk.last.unwrap_or(false) {
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"bot_reply_audio_write_finished",
			"ok",
			None,
			None,
			json!({
			"replyPlaybackMode": state.reply_playback_mode.as_str(),
			"format": format.as_str(),
			"chunkSeq": audio_chunk.chunk_seq,
			"replyTotalAfterVadEndMs": turn_pipeline_started_at.elapsed().as_millis() as u64,
			}),
			);
			}
			Ok(frames.len())
			}

			fn pcm_s16le_payload_to_frames(
			payload: &[u8],
			sample_rate: u32,
			channels: u32,
			) -> Result<Vec<PcmFrame>> {
			audio::pcm_s16le_bytes_to_frames(
			payload,
			sample_rate,
			channels,
			TARGET_SAMPLE_RATE_HZ,
			TARGET_NUM_CHANNELS,
			)
			}

			fn pcm_s16le_frame_alignment_bytes(channels: u32) -> Result<usize> {
			if channels == 0 {
			return Err(anyhow!("pcm_s16le channel count is zero"));
			}
			let channel_count = usize::try_from(channels)
			.map_err(\|_\| anyhow!("unsupported pcm_s16le channel count {channels}"))?;
			Ok(2 * channel_count)
			}

			fn take_aligned_pcm_payload(
			buffer: &mut Vec<u8>,
			payload: &[u8],
			frame_alignment_bytes: usize,
			last: bool,
			) -> (Vec<u8>, usize) {
			let alignment = frame_alignment_bytes.max(2);
			buffer.extend_from_slice(payload);
			let aligned_len = buffer.len() - buffer.len() % alignment;
			let aligned_payload = if aligned_len == 0 {
			Vec::new()
			} else {
			buffer.drain(..aligned_len).collect()
			};
			let dropped_tail_bytes = if last && !buffer.is_empty() {
			let dropped = buffer.len();
			buffer.clear();
			dropped
			} else {
			0
			};
			(aligned_payload, dropped_tail_bytes)
			}

			#[cfg(test)]
			mod pcm_stream_tests {
			use super::take_aligned_pcm_payload;

			#[test]
			fn take_aligned_pcm_payload_buffers_split_sample_bytes() {
			let mut buffer = Vec::new();

			let (first, dropped) = take_aligned_pcm_payload(&mut buffer, &[0x01], 2, false);
			assert!(first.is_empty());
			assert_eq!(0, dropped);
			assert_eq!(vec![0x01], buffer);

			let (second, dropped) = take_aligned_pcm_payload(&mut buffer, &[0x02, 0x03], 2, false);
			assert_eq!(vec![0x01, 0x02], second);
			assert_eq!(0, dropped);
			assert_eq!(vec![0x03], buffer);

			let (third, dropped) = take_aligned_pcm_payload(&mut buffer, &[0x04], 2, true);
			assert_eq!(vec![0x03, 0x04], third);
			assert_eq!(0, dropped);
			assert!(buffer.is_empty());
			}

			#[test]
			fn take_aligned_pcm_payload_drops_final_half_sample() {
			let mut buffer = Vec::new();

			let (payload, dropped) =
			take_aligned_pcm_payload(&mut buffer, &[0x01, 0x02, 0x03], 2, true);
			assert_eq!(vec![0x01, 0x02], payload);
			assert_eq!(1, dropped);
			assert!(buffer.is_empty());
			}
			}

			fn trim_ascii_whitespace(value: &[u8]) -> &[u8] {
			let mut start = 0;
			let mut end = value.len();
			while start < end && value[start].is_ascii_whitespace() {
			start += 1;
			}
			while end > start && value[end - 1].is_ascii_whitespace() {
			end -= 1;
			}
			&value[start..end]
			}

			async fn request_turn_bridge(
			http: &Client,
			bridge_config: &TurnBridgeConfig,
			call_id: &str,
			trace_id: &str,
			turn: &FinishedSpeechTurn,
			path_ref: &str,
			byte_size: u64,
			turn_pipeline_started_at: Instant,
			) -> Result<RuntimeTurnBridgeOutcome> {
			let bridge_started_at = Instant::now();
			let request = RuntimeTurnRequest {
			call_id: call_id.to_string(),
			trace_id: trace_id.to_string(),
			turn_id: turn.turn_id.clone(),
			audio_artifact: RuntimeTurnAudioArtifact {
			artifact_type: "local_file".to_string(),
			path_ref: path_ref.to_string(),
			format: "wav".to_string(),
			sample_rate: TARGET_SAMPLE_RATE_HZ,
			channels: u32::from(TARGET_NUM_CHANNELS),
			duration_ms: turn.duration_ms,
			byte_size,
			},
			};
			let response = http
			.post(bridge_config.bridge_url.as_deref().unwrap_or_default())
			.header(
			"X-CV-Runtime-Token",
			bridge_config.bridge_token.as_deref().unwrap_or_default(),
			)
			.header("X-CV-Call-Id", call_id)
			.header("X-CV-Trace-Id", trace_id)
			.header(
			"X-CV-Runtime-Session-Nonce",
			bridge_config
			.runtime_session_nonce
			.as_deref()
			.unwrap_or_default(),
			)
			.json(&request)
			.send()
			.await
			.context("failed to post turn bridge")?;
			let status = response.status();
			let body = response
			.text()
			.await
			.context("failed to read turn bridge response")?;
			let body_len = body.len();
			let parsed: Option<RuntimeTurnCommonResult<RuntimeTurnResponseData>> =
			serde_json::from_str(&body).ok();
			if !status.is_success() {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			http_status = status.as_u16(),
			body_len,
			code = parsed.as_ref().map(\|value\| value.code).unwrap_or_default(),
			reason_code = %parsed.as_ref().and_then(\|value\| value.msg.as_deref()).unwrap_or("unknown"),
			"runtime helper turn_bridge_http_failed"
			);
			return Err(anyhow!("turn bridge http failed"));
			}
			let Some(result) = parsed else {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			body_len,
			"runtime helper turn_bridge_response_invalid"
			);
			return Err(anyhow!("turn bridge response invalid"));
			};
			if result.code != 0 {
			warn!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			code = result.code,
			reason_code = %result.msg.as_deref().unwrap_or("unknown"),
			retryable = result.retryable.unwrap_or(false),
			stage = %result.stage.as_deref().unwrap_or("unknown"),
			"runtime helper turn_bridge_business_failed"
			);
			return Err(anyhow!("turn bridge business failed"));
			}
			let data = result.data;
			let reply_audio_artifact = data
			.as_ref()
			.and_then(\|value\| value.reply_audio_artifact.as_ref());
			let device_outputs = data
			.as_ref()
			.and_then(\|value\| value.device_outputs.clone())
			.unwrap_or_default();
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			response_turn_id = %data.as_ref().and_then(\|value\| value.turn_id.as_deref()).unwrap_or("unknown"),
			message_id_alias = %data.as_ref().and_then(\|value\| value.message_id.as_deref()).map(redact).unwrap_or_else(\|\| "none".to_string()),
			reply_audio_present = reply_audio_artifact.is_some(),
			reply_audio_type = %reply_audio_artifact.and_then(\|value\| value.artifact_type.as_deref()).unwrap_or("none"),
			reply_audio_path_alias = %reply_audio_artifact.and_then(\|value\| value.path_ref.as_deref()).map(redact).unwrap_or_else(\|\| "none".to_string()),
			reply_audio_format = %reply_audio_artifact.and_then(\|value\| value.format.as_deref()).unwrap_or("none"),
			device_output_count = device_outputs.len(),
			"runtime helper turn_bridge_completed"
			);
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"turn_bridge_completed",
			"ok",
			None,
			None,
			json!({
			"bridgeWallDurationMs": bridge_started_at.elapsed().as_millis() as u64,
			"replyAudioPresent": reply_audio_artifact.is_some(),
			"deviceOutputCount": device_outputs.len(),
			"replyTotalAfterVadEndMs": turn_pipeline_started_at.elapsed().as_millis() as u64,
			}),
			);
			Ok(RuntimeTurnBridgeOutcome {
			reply_audio_artifact: reply_audio_artifact.cloned(),
			device_outputs,
			})
			}

			async fn write_reply_audio_artifact(
			http: &Client,
			bridge_config: &TurnBridgeConfig,
			sink: &BotAudioOutputSink,
			call_id: &str,
			trace_id: &str,
			turn: &FinishedSpeechTurn,
			artifact: &RuntimeTurnReplyAudioArtifact,
			turn_pipeline_started_at: Instant,
			) -> Result<()> {
			let artifact_type = artifact.artifact_type.as_deref().unwrap_or_default().trim();
			if artifact_type != "local_file" {
			return Err(anyhow!("unsupported reply audio artifact type"));
			}
			let path_ref = artifact
			.path_ref
			.as_deref()
			.map(str::trim)
			.filter(\|value\| !value.is_empty())
			.ok_or_else(\|\| anyhow!("reply audio pathRef missing"))?;
			let artifact_root = PathBuf::from(bridge_config.artifact_dir.as_deref().unwrap_or_default());
			let audio_path = resolve_artifact_path(&artifact_root, path_ref)?;
			let audio_path_string = audio_path.to_string_lossy().to_string();
			let reply_audio_format = artifact.format.as_deref().unwrap_or("unknown");

			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			reply_audio_type = %artifact_type,
			reply_audio_path_alias = %redact(path_ref),
			reply_audio_format = %reply_audio_format,
			"runtime helper bot_reply_audio_write_started"
			);
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"bot_reply_audio_write_started",
			"ok",
			None,
			None,
			json!({
			"replyAudioFormat": reply_audio_format,
			"replyTotalAfterVadEndMs": turn_pipeline_started_at.elapsed().as_millis() as u64,
			}),
			);

			let reply_debug_label = format!("reply-{}", turn.turn_id);
			let loaded_audio = load_pre_recorded_frames(
			http,
			Some(&audio_path_string),
			None,
			TARGET_SAMPLE_RATE_HZ,
			TARGET_NUM_CHANNELS,
			bridge_config.audio_debug_dump_dir.as_deref(),
			call_id,
			&reply_debug_label,
			)
			.await?
			.ok_or_else(\|\| anyhow!("reply audio artifact decode returned empty"))?;
			let AudioDiagnostics {
			source_format,
			source_bytes,
			source_sample_rate_hz,
			source_num_channels,
			target_duration_ms,
			frame_count,
			rms,
			peak,
			clipped_sample_count,
			silence_ratio,
			mp3_skipped_data_count,
			mp3_insufficient_data_count,
			debug_source_path,
			debug_pcm_wav_path,
			..
			} = loaded_audio.diagnostics;
			let frames = loaded_audio.frames;

			let playback_started_at = Instant::now();
			let pacing_started_at = tokio::time::Instant::now();
			for (index, frame) in frames.iter().enumerate() {
			sink.write_pcm_frame(frame).await?;
			sleep_until(pacing_started_at + Duration::from_millis(((index + 1) as u64) * 20)).await;
			}
			let playback_wall_ms = playback_started_at.elapsed().as_millis() as i64;
			let drift_ms = playback_wall_ms - target_duration_ms as i64;
			sink.clear_buffer();

			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn.turn_id,
			source_format,
			source_bytes,
			source_sample_rate_hz,
			source_num_channels,
			frame_count,
			theoretical_duration_ms = target_duration_ms,
			push_wall_duration_ms = playback_wall_ms,
			push_drift_ms = drift_ms,
			rms = round4(rms),
			peak = round4(peak),
			clipped_sample_count,
			silence_ratio = round4(silence_ratio),
			mp3_skipped_data_count,
			mp3_insufficient_data_count,
			debug_source_path = debug_source_path.as_deref().unwrap_or(""),
			debug_pcm_wav_path = debug_pcm_wav_path.as_deref().unwrap_or(""),
			"runtime helper bot_reply_audio_write_finished"
			);
			emit_activity(
			call_id,
			trace_id,
			Some(&turn.turn_id),
			"bot_reply_audio_write_finished",
			"ok",
			None,
			None,
			json!({
			"sourceFormat": source_format,
			"sourceBytes": source_bytes,
			"sourceSampleRateHz": source_sample_rate_hz,
			"sourceNumChannels": source_num_channels,
			"frameCount": frame_count,
			"theoreticalDurationMs": target_duration_ms,
			"pushWallDurationMs": playback_wall_ms,
			"pushDriftMs": drift_ms,
			"rms": round4(rms),
			"peak": round4(peak),
			"clippedSampleCount": clipped_sample_count,
			"silenceRatio": round4(silence_ratio),
			"mp3SkippedDataCount": mp3_skipped_data_count,
			"mp3InsufficientDataCount": mp3_insufficient_data_count,
			"replyTotalAfterVadEndMs": turn_pipeline_started_at.elapsed().as_millis() as u64,
			}),
			);
			Ok(())
			}

			fn build_device_output_smoke_payload(config: &Config) -> DeviceOutputMessage {
			DeviceOutputMessage {
			message_type: DEVICE_OUTPUT_TOPIC,
			schema_version: "1.0",
			call_id: config.call_id.clone(),
			role_id: config.role_id.clone(),
			trace_id: config.trace_id.clone(),
			ack_mode: "http",
			sensor_instructions: vec![
			SensorInstruction {
			command_id: command_id(&config.call_id, 1),
			sensor_type: "Vibrator",
			operation_type: "VibratorStart",
			step: 1,
			duration_sec: None,
			extension: r#"{"levelList":[{"level":1,"percent":"0.6"}]}"#.to_string(),
			},
			SensorInstruction {
			command_id: command_id(&config.call_id, 2),
			sensor_type: "Vibrator",
			operation_type: "VibratorUp",
			step: 1,
			duration_sec: None,
			extension: r#"{"delta":1}"#.to_string(),
			},
			SensorInstruction {
			command_id: command_id(&config.call_id, 3),
			sensor_type: "Pump",
			operation_type: "JiaStart",
			step: 1,
			duration_sec: None,
			extension: r#"{"levelList":[{"level":1,"percent":"0.5"}]}"#.to_string(),
			},
			SensorInstruction {
			command_id: command_id(&config.call_id, 4),
			sensor_type: "Heating",
			operation_type: "HeatingStart",
			step: 1,
			duration_sec: Some(3),
			extension: r#"{"target":"warm"}"#.to_string(),
			},
			],
			fn resolve_artifact_path(artifact_root: &Path, path_ref: &str) -> Result<PathBuf> {
			let path_ref = path_ref.trim();
			if path_ref.is_empty() {
			return Err(anyhow!("empty artifact pathRef"));
			}
			let relative = Path::new(path_ref);
			if relative.is_absolute() {
			return Err(anyhow!("absolute artifact pathRef is not allowed"));
			}
			let mut safe_relative = PathBuf::new();
			for component in relative.components() {
			match component {
			std::path::Component::Normal(segment) => {
			let segment = segment
			.to_str()
			.ok_or_else(\|\| anyhow!("non-utf8 artifact pathRef segment"))?;
			require_safe_segment(segment)?;
			safe_relative.push(segment);
			}
			std::path::Component::CurDir => {}
			_ => return Err(anyhow!("unsafe artifact pathRef component")),
			}
			}
			if safe_relative.as_os_str().is_empty() {
			return Err(anyhow!("artifact pathRef has no safe components"));
			}
			let root = normalize_path_lexically(artifact_root);
			let output_path = normalize_path_lexically(&root.join(safe_relative));
			if !output_path.starts_with(&root) {
			return Err(anyhow!("reply artifact path escapes root"));
			}
			Ok(output_path)
			}

			#[derive(Serialize)]
			struct RuntimeTurnRequest {
			#[serde(rename = "callId")]
			call_id: String,
			#[serde(rename = "traceId")]
			trace_id: String,
			#[serde(rename = "turnId")]
			turn_id: String,
			#[serde(rename = "audioArtifact")]
			audio_artifact: RuntimeTurnAudioArtifact,
			}

			#[derive(Serialize)]
			struct RuntimeTurnAudioArtifact {
			#[serde(rename = "type")]
			artifact_type: String,
			#[serde(rename = "pathRef")]
			path_ref: String,
			format: String,
			#[serde(rename = "sampleRate")]
			sample_rate: u32,
			channels: u32,
			#[serde(rename = "durationMs")]
			duration_ms: u64,
			#[serde(rename = "byteSize")]
			byte_size: u64,
			}

			#[derive(Deserialize)]
			struct RuntimeTurnCommonResult<T> {
			code: i64,
			msg: Option<String>,
			data: Option<T>,
			stage: Option<String>,
			retryable: Option<bool>,
			}

			#[derive(Default)]
			struct RuntimeTurnBridgeOutcome {
			reply_audio_artifact: Option<RuntimeTurnReplyAudioArtifact>,
			device_outputs: Vec<RuntimeTurnDeviceOutput>,
			}

			struct RuntimeTurnStreamOutcome {
			reply_playback_mode: String,
			audio_chunk_count: u64,
			device_output_count: u64,
			}

			struct RuntimeTurnStreamState {
			reply_playback_mode: String,
			reply_state_seq: u64,
			playback_started_sent: bool,
			first_audio_frame_written: bool,
			completed: bool,
			audio_chunk_count: u64,
			device_output_count: u64,
			encoded_audio_buffer: Vec<u8>,
			pcm_audio_buffer: Vec<u8>,
			}

			impl Default for RuntimeTurnStreamState {
			fn default() -> Self {
			Self {
			reply_playback_mode: "full_tts_fallback".to_string(),
			reply_state_seq: 0,
			playback_started_sent: false,
			first_audio_frame_written: false,
			completed: false,
			audio_chunk_count: 0,
			device_output_count: 0,
			encoded_audio_buffer: Vec::new(),
			pcm_audio_buffer: Vec::new(),
			}
			}
			}

			fn command_id(call_id: &str, sequence: u8) -> String {
			format!("{call_id}-device-smoke-{sequence:03}")
			#[derive(Deserialize)]
			struct RuntimeTurnResponseData {
			#[serde(rename = "turnId")]
			turn_id: Option<String>,
			#[serde(rename = "messageId")]
			message_id: Option<String>,
			#[serde(rename = "replyAudioArtifact")]
			reply_audio_artifact: Option<RuntimeTurnReplyAudioArtifact>,
			#[serde(rename = "deviceOutputs")]
			device_outputs: Option<Vec<RuntimeTurnDeviceOutput>>,
			}

			#[derive(Deserialize)]
			struct RuntimeTurnStreamEvent {
			#[serde(rename = "type", alias = "event")]
			event_type: Option<String>,
			#[serde(rename = "seq")]
			seq: Option<u64>,
			#[serde(rename = "replyPlaybackMode")]
			reply_playback_mode: Option<String>,
			state: Option<String>,
			#[serde(rename = "audioChunk")]
			audio_chunk: Option<RuntimeTurnStreamAudioChunk>,
			activity: Option<RuntimeTurnStreamActivity>,
			#[serde(rename = "deviceOutput")]
			device_output: Option<RuntimeTurnDeviceOutput>,
			error: Option<RuntimeTurnStreamError>,
			completion: Option<RuntimeTurnStreamCompletion>,
			diagnostics: Option<serde_json::Value>,
			}

			impl RuntimeTurnStreamEvent {
			fn event_type(&self) -> Option<String> {
			self.event_type.as_deref().map(\|value\| match value {
			"reply_playback_mode_selected" => "reply_playback_mode_selected".to_string(),
			"reply_state" => "reply_state".to_string(),
			"reply_audio_chunk" => "reply_audio_chunk".to_string(),
			"device_output" => "device_output".to_string(),
			"turn_completed" => "turn_completed".to_string(),
			"turn_failed" => "turn_failed".to_string(),
			"turn_cancelled" => "turn_cancelled".to_string(),
			"activity" => "activity".to_string(),
			other => other.to_string(),
			})
			}
			}

			#[derive(Deserialize)]
			struct RuntimeTurnStreamAudioChunk {
			#[serde(rename = "chunkSeq", alias = "seq")]
			chunk_seq: Option<u64>,
			format: Option<String>,
			#[serde(rename = "sampleRate")]
			sample_rate: Option<u32>,
			channels: Option<u32>,
			#[serde(rename = "payloadBase64", alias = "audioBase64")]
			payload_base64: Option<String>,
			last: Option<bool>,
			}

			#[derive(Deserialize)]
			struct RuntimeTurnStreamActivity {
			#[serde(rename = "eventType", alias = "event")]
			event_type: Option<String>,
			stage: Option<String>,
			#[serde(rename = "reasonCode")]
			reason_code: Option<String>,
			}

			#[derive(Deserialize)]
			struct RuntimeTurnStreamError {
			#[serde(rename = "reasonCode")]
			reason_code: Option<String>,
			stage: Option<String>,
			retryable: Option<bool>,
			}

			#[derive(Deserialize)]
			struct RuntimeTurnStreamCompletion {
			#[serde(rename = "messageId")]
			message_id: Option<String>,
			}

			#[derive(Clone, Deserialize)]
			struct RuntimeTurnReplyAudioArtifact {
			#[serde(rename = "type")]
			artifact_type: Option<String>,
			#[serde(rename = "pathRef")]
			path_ref: Option<String>,
			format: Option<String>,
			}

			#[derive(Clone, Deserialize)]
			struct RuntimeTurnDeviceOutput {
			#[serde(rename = "commandId")]
			command_id: Option<String>,
			#[serde(rename = "commandCode")]
			command_code: Option<String>,
			params: Option<serde_json::Value>,
			}

			fn require_safe_segment(value: &str) -> Result<()> {
			if value.is_empty()
			\|\| value.contains('/')
			\|\| value.contains("..")
			\|\| !value
			.chars()
			.all(\|ch\| ch.is_ascii_alphanumeric() \|\| matches!(ch, '_' \| '-' \| '.'))
			{
			return Err(anyhow!("unsafe path segment"));
			}
			Ok(())
			}

			fn normalize_path_lexically(path: &Path) -> PathBuf {
			let mut normalized = PathBuf::new();
			for component in path.components() {
			match component {
			std::path::Component::CurDir => {}
			std::path::Component::ParentDir => {
			normalized.pop();
			}
			_ => normalized.push(component.as_os_str()),
			}
			}
			normalized
			}

			fn spawn_user_audio_frame_observer(
			track: RemoteAudioTrack,
			call_id: String,
			trace_id: String,
			participant_alias: String,
			track_sid_alias: String,
			simple_vad_enabled: bool,
			simple_vad_config: SimpleVadConfig,
			vad_enabled_gate: Arc<AtomicBool>,
			turn_bridge_config: TurnBridgeConfig,
			http: Client,
			sink: Arc<BotAudioOutputSink>,
			) -> JoinHandle<()> {
			tokio::spawn(async move {
			let mut stream = NativeAudioStream::new(
			track.rtc_track(),
			TARGET_SAMPLE_RATE_HZ as i32,
			i32::from(TARGET_NUM_CHANNELS),
			);
			let started_at = Instant::now();
			let mut frame_count: u64 = 0;
			let mut sample_count: u64 = 0;
			let mut simple_vad = if simple_vad_enabled {
			Some(SimpleVad::new(simple_vad_config))
			} else {
			None
			};

			while let Some(frame) = stream.next().await {
			frame_count += 1;
			sample_count += u64::from(frame.samples_per_channel) * u64::from(frame.num_channels);
			let elapsed_ms = started_at.elapsed().as_millis() as u64;
			if frame_count == 1 {
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			participant_alias = %participant_alias,
			track_sid_alias = %track_sid_alias,
			sample_rate_hz = frame.sample_rate,
			num_channels = frame.num_channels,
			samples_per_channel = frame.samples_per_channel,
			first_frame_elapsed_ms = elapsed_ms,
			"runtime helper user_audio_frame_received"
			);
			} else if frame_count % 250 == 0 {
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			participant_alias = %participant_alias,
			track_sid_alias = %track_sid_alias,
			frame_count,
			sample_count,
			observed_wall_ms = elapsed_ms,
			"runtime helper user_audio_frame_summary"
			);
			}

			if let Some(vad) = simple_vad.as_mut() {
			if vad_enabled_gate.load(Ordering::Acquire) {
			if let Some(turn) = vad.observe_frame(
			&call_id,
			&trace_id,
			&participant_alias,
			&track_sid_alias,
			frame_count,
			elapsed_ms,
			&frame,
			) {
			handle_finished_turn(
			&http,
			&turn_bridge_config,
			&sink,
			&call_id,
			&trace_id,
			turn,
			)
			.await;
			}
			} else {
			vad.observe_disabled_frame(
			&call_id,
			&trace_id,
			&participant_alias,
			&track_sid_alias,
			frame_count,
			elapsed_ms,
			);
			}
			}
			}

			if let Some(vad) = simple_vad.as_mut() {
			if let Some(turn) = vad.finish_stream(
			&call_id,
			&trace_id,
			&participant_alias,
			&track_sid_alias,
			started_at.elapsed().as_millis() as u64,
			) {
			handle_finished_turn(&http, &turn_bridge_config, &sink, &call_id, &trace_id, turn)
			.await;
			}
			}

			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			participant_alias = %participant_alias,
			track_sid_alias = %track_sid_alias,
			frame_count,
			sample_count,
			observed_wall_ms = started_at.elapsed().as_millis() as u64,
			"runtime helper user_audio_stream_ended"
			);
			})
			}

			#[derive(Clone)]
			struct SimpleVadConfig {
			rms_threshold: f64,
			peak_threshold: f64,
			start_frames: u32,
			end_silence_ms: u64,
			min_speech_ms: u64,
			max_turn_ms: u64,
			initial_ignore_ms: u64,
			}

			impl SimpleVadConfig {
			fn from_env() -> Self {
			Self {
			rms_threshold: f64_env("CV_VAD_RMS_THRESHOLD", 0.012),
			peak_threshold: f64_env("CV_VAD_PEAK_THRESHOLD", 0.08),
			start_frames: u32_env("CV_VAD_START_FRAMES", 5).max(1),
			end_silence_ms: u64_env("CV_VAD_END_SILENCE_MS", 700).max(100),
			min_speech_ms: u64_env("CV_VAD_MIN_SPEECH_MS", 300).max(1),
			max_turn_ms: u64_env("CV_VAD_MAX_TURN_MS", 10_000).max(1_000),
			initial_ignore_ms: u64_env("CV_VAD_INITIAL_IGNORE_MS", 500),
			}
			}

			fn end_silence_frames(&self, frame_duration_ms: u64) -> u32 {
			let frame_duration_ms = frame_duration_ms.max(1);
			self.end_silence_ms.div_ceil(frame_duration_ms) as u32
			}
			}

			struct SimpleVad {
			config: SimpleVadConfig,
			turn_index: u64,
			in_speech: bool,
			voiced_run_frames: u32,
			silence_run_frames: u32,
			speech_start_elapsed_ms: u64,
			speech_frame_count: u64,
			speech_sample_count: u64,
			speech_rms_sum: f64,
			speech_peak: f64,
			ignored_before_enabled_frames: u64,
			pre_speech_frames: Vec<Vec<i16>>,
			speech_samples: Vec<i16>,
			}

			struct FinishedSpeechTurn {
			turn_index: u64,
			turn_id: String,
			samples: Vec<i16>,
			duration_ms: u64,
			frame_count: u64,
			sample_count: u64,
			end_reason: String,
			}

			impl SimpleVad {
			fn new(config: SimpleVadConfig) -> Self {
			Self {
			config,
			turn_index: 0,
			in_speech: false,
			voiced_run_frames: 0,
			silence_run_frames: 0,
			speech_start_elapsed_ms: 0,
			speech_frame_count: 0,
			speech_sample_count: 0,
			speech_rms_sum: 0.0,
			speech_peak: 0.0,
			ignored_before_enabled_frames: 0,
			pre_speech_frames: Vec::new(),
			speech_samples: Vec::new(),
			}
			}

			fn observe_disabled_frame(
			&mut self,
			call_id: &str,
			trace_id: &str,
			participant_alias: &str,
			track_sid_alias: &str,
			frame_count: u64,
			elapsed_ms: u64,
			) {
			self.reset_current_turn();
			self.ignored_before_enabled_frames = self.ignored_before_enabled_frames.saturating_add(1);
			if self.ignored_before_enabled_frames == 1 \|\| self.ignored_before_enabled_frames % 250 == 0
			{
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			participant_alias = %participant_alias,
			track_sid_alias = %track_sid_alias,
			frame_count,
			ignored_frame_count = self.ignored_before_enabled_frames,
			elapsed_ms,
			"runtime helper vad_ignored_before_enabled"
			);
			emit_activity(
			call_id,
			trace_id,
			None,
			"ignored_user_audio_before_vad_enabled",
			"ok",
			None,
			None,
			json!({
			"frameCount": frame_count,
			"ignoredFrameCount": self.ignored_before_enabled_frames,
			"elapsedMs": elapsed_ms,
			}),
			);
			}
			}

			fn observe_frame(
			&mut self,
			call_id: &str,
			trace_id: &str,
			participant_alias: &str,
			track_sid_alias: &str,
			frame_count: u64,
			elapsed_ms: u64,
			frame: &AudioFrame<'_>,
			) -> Option<FinishedSpeechTurn> {
			let frame_duration_ms = frame_duration_ms(frame);
			let (rms, peak) = pcm_energy_stats(frame.data.as_ref());
			if elapsed_ms < self.config.initial_ignore_ms {
			return None;
			}

			let voiced = rms >= self.config.rms_threshold \|\| peak >= self.config.peak_threshold;
			if !self.in_speech {
			self.remember_pre_speech_frame(frame);
			}
			if voiced {
			self.voiced_run_frames = self.voiced_run_frames.saturating_add(1);
			self.silence_run_frames = 0;
			} else {
			self.voiced_run_frames = 0;
			self.silence_run_frames = self.silence_run_frames.saturating_add(1);
			}

			if !self.in_speech {
			if self.voiced_run_frames >= self.config.start_frames {
			self.turn_index += 1;
			self.in_speech = true;
			self.speech_start_elapsed_ms = elapsed_ms
			.saturating_sub(u64::from(self.config.start_frames) * frame_duration_ms);
			self.speech_frame_count = u64::from(self.config.start_frames);
			self.speech_sample_count = u64::from(frame.samples_per_channel)
			* u64::from(frame.num_channels)
			* u64::from(self.config.start_frames);
			self.speech_rms_sum = rms * f64::from(self.config.start_frames);
			self.speech_peak = peak;
			self.speech_samples = self
			.pre_speech_frames
			.iter()
			.flat_map(\|samples\| samples.iter().copied())
			.collect();
			let turn_id = format!("turn-{:04}", self.turn_index);
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			participant_alias = %participant_alias,
			track_sid_alias = %track_sid_alias,
			turn_index = self.turn_index,
			frame_count,
			speech_start_elapsed_ms = self.speech_start_elapsed_ms,
			rms = round4(rms),
			peak = round4(peak),
			"runtime helper vad_speech_start"
			);
			emit_activity(
			call_id,
			trace_id,
			Some(&turn_id),
			"vad_speech_start",
			"ok",
			None,
			None,
			json!({
			"turnIndex": self.turn_index,
			"frameCount": frame_count,
			"speechStartElapsedMs": self.speech_start_elapsed_ms,
			"rms": round4(rms),
			"peak": round4(peak),
			}),
			);
			}
			return None;
			}

			self.speech_samples.extend_from_slice(frame.data.as_ref());
			self.speech_frame_count += 1;
			self.speech_sample_count +=
			u64::from(frame.samples_per_channel) * u64::from(frame.num_channels);
			self.speech_rms_sum += rms;
			self.speech_peak = self.speech_peak.max(peak);

			let speech_duration_ms = elapsed_ms.saturating_sub(self.speech_start_elapsed_ms);
			if speech_duration_ms >= self.config.max_turn_ms {
			return self.finish_turn(
			call_id,
			trace_id,
			participant_alias,
			track_sid_alias,
			elapsed_ms,
			"max_turn_ms",
			);
			}

			if !voiced && self.silence_run_frames >= self.config.end_silence_frames(frame_duration_ms) {
			return self.finish_turn(
			call_id,
			trace_id,
			participant_alias,
			track_sid_alias,
			elapsed_ms,
			"silence",
			);
			}
			None
			}

			fn finish_stream(
			&mut self,
			call_id: &str,
			trace_id: &str,
			participant_alias: &str,
			track_sid_alias: &str,
			elapsed_ms: u64,
			) -> Option<FinishedSpeechTurn> {
			if self.in_speech {
			return self.finish_turn(
			call_id,
			trace_id,
			participant_alias,
			track_sid_alias,
			elapsed_ms,
			"stream_end",
			);
			} else if self.turn_index == 0 {
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			participant_alias = %participant_alias,
			track_sid_alias = %track_sid_alias,
			observed_wall_ms = elapsed_ms,
			"runtime helper vad_no_speech_summary"
			);
			}
			None
			}

			fn finish_turn(
			&mut self,
			call_id: &str,
			trace_id: &str,
			participant_alias: &str,
			track_sid_alias: &str,
			elapsed_ms: u64,
			end_reason: &str,
			) -> Option<FinishedSpeechTurn> {
			let speech_duration_ms = elapsed_ms.saturating_sub(self.speech_start_elapsed_ms);
			let event_name = if speech_duration_ms < self.config.min_speech_ms {
			"runtime helper vad_speech_too_short"
			} else {
			"runtime helper vad_speech_end"
			};
			let avg_rms = if self.speech_frame_count == 0 {
			0.0
			} else {
			self.speech_rms_sum / self.speech_frame_count as f64
			};

			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			participant_alias = %participant_alias,
			track_sid_alias = %track_sid_alias,
			turn_index = self.turn_index,
			speech_start_elapsed_ms = self.speech_start_elapsed_ms,
			speech_end_elapsed_ms = elapsed_ms,
			speech_duration_ms,
			speech_frame_count = self.speech_frame_count,
			speech_sample_count = self.speech_sample_count,
			avg_rms = round4(avg_rms),
			peak = round4(self.speech_peak),
			end_reason = %end_reason,
			"{}", event_name
			);

			let finished_turn = if speech_duration_ms >= self.config.min_speech_ms {
			let turn_id = format!("turn-{:04}", self.turn_index);
			emit_activity(
			call_id,
			trace_id,
			Some(&turn_id),
			"vad_speech_end",
			"ok",
			None,
			None,
			json!({
			"turnIndex": self.turn_index,
			"speechStartElapsedMs": self.speech_start_elapsed_ms,
			"speechEndElapsedMs": elapsed_ms,
			"speechDurationMs": speech_duration_ms,
			"speechFrameCount": self.speech_frame_count,
			"speechSampleCount": self.speech_sample_count,
			"avgRms": round4(avg_rms),
			"peak": round4(self.speech_peak),
			"endReason": end_reason,
			}),
			);
			Some(FinishedSpeechTurn {
			turn_index: self.turn_index,
			turn_id,
			samples: std::mem::take(&mut self.speech_samples),
			duration_ms: speech_duration_ms,
			frame_count: self.speech_frame_count,
			sample_count: self.speech_sample_count,
			end_reason: end_reason.to_string(),
			})
			} else {
			None
			};
			self.reset_current_turn();
			finished_turn
			}

			fn reset_current_turn(&mut self) {
			self.in_speech = false;
			self.voiced_run_frames = 0;
			self.silence_run_frames = 0;
			self.speech_start_elapsed_ms = 0;
			self.speech_frame_count = 0;
			self.speech_sample_count = 0;
			self.speech_rms_sum = 0.0;
			self.speech_peak = 0.0;
			self.speech_samples.clear();
			self.pre_speech_frames.clear();
			}

			fn remember_pre_speech_frame(&mut self, frame: &AudioFrame<'_>) {
			self.pre_speech_frames.push(frame.data.as_ref().to_vec());
			let max_frames = self.config.start_frames as usize;
			if self.pre_speech_frames.len() > max_frames {
			let remove_count = self.pre_speech_frames.len() - max_frames;
			self.pre_speech_frames.drain(0..remove_count);
			}
			}
			}

			fn frame_duration_ms(frame: &AudioFrame<'_>) -> u64 {
			if frame.sample_rate == 0 {
			return 10;
			}
			((u64::from(frame.samples_per_channel) * 1000) / u64::from(frame.sample_rate)).max(1)
			}

			fn pcm_energy_stats(samples: &[i16]) -> (f64, f64) {
			if samples.is_empty() {
			return (0.0, 0.0);
			}
			let mut square_sum = 0.0;
			let mut peak = 0.0;
			for sample in samples {
			let normalized = f64::from(*sample) / f64::from(i16::MAX);
			square_sum += normalized * normalized;
			let abs = normalized.abs();
			if abs > peak {
			peak = abs;
			}
			}
			((square_sum / samples.len() as f64).sqrt(), peak)
			}

			fn round4(value: f64) -> f64 {
			(value * 10_000.0).round() / 10_000.0
			}

			struct BotAudioOutputSink {
			room: Arc<Room>,
			rtc_source: NativeAudioSource,
			track: LocalAudioTrack,
			device_output_destination_identity: Option<String>,
			}

			impl BotAudioOutputSink {
			@@ -339,9 +2608,12 @@
			room: Arc<Room>,
			room_name: &str,
			participant_identity: &str,
			call_id: &str,
			trace_id: &str,
			track_name: &str,
			sample_rate: u32,
			num_channels: u32,
			device_output_destination_identity: Option<String>,
			) -> Result<Self> {
			let rtc_source = NativeAudioSource::new(
			AudioSourceOptions::default(),
			@@ -353,6 +2625,8 @@
			track_name,
			RtcAudioSource::Native(rtc_source.clone()),
			);
			let room_alias = redact(room_name);
			let participant_alias = redact(participant_identity);

			room.local_participant()
			.publish_track(
			@@ -362,26 +2636,205 @@
			.await
			.map_err(\|error\| {
			anyhow!(
			"failed to publish bot audio track in room {room_name} for participant {participant_identity}: {error}"
			"failed to publish bot audio track in room {room_alias} for participant {participant_alias}: {error}"
			)
			})?;

			info!(
			room_id = %room_name,
			participant_alias = %redact(participant_identity),
			room_alias = %room_alias,
			participant_alias = %participant_alias,
			track_name = %track_name,
			sample_rate,
			num_channels,
			"runtime helper published bot audio track"
			);
			emit_activity(
			call_id,
			trace_id,
			None,
			"bot_track_ready",
			"ok",
			None,
			None,
			json!({
			"trackName": track_name,
			"sampleRate": sample_rate,
			"numChannels": num_channels,
			}),
			);

			Ok(Self {
			room,
			rtc_source,
			track,
			device_output_destination_identity,
			})
			}

			async fn publish_device_output(
			&self,
			call_id: &str,
			trace_id: &str,
			turn_id: &str,
			output: &RuntimeTurnDeviceOutput,
			) -> Result<()> {
			let command_id = output
			.command_id
			.as_deref()
			.map(str::trim)
			.filter(\|value\| !value.is_empty())
			.ok_or_else(\|\| anyhow!("device output commandId missing"))?;
			let command_code = output
			.command_code
			.as_deref()
			.map(str::trim)
			.filter(\|value\| !value.is_empty())
			.ok_or_else(\|\| anyhow!("device output commandCode missing"))?;
			let payload = serde_json::json!({
			"type": "device_output",
			"schemaVersion": "1.0",
			"callId": call_id,
			"traceId": trace_id,
			"turnId": turn_id,
			"commandId": command_id,
			"commandCode": command_code,
			"params": output.params.clone().unwrap_or_else(\|\| serde_json::json!({})),
			"source": {
			"kind": "voice_command"
			},
			});
			let destinations = self
			.device_output_destination_identity
			.as_ref()
			.filter(\|value\| !value.trim().is_empty())
			.map(\|value\| vec![ParticipantIdentity(value.trim().to_string())])
			.unwrap_or_default();
			let destination_count = destinations.len();
			self.room
			.local_participant()
			.publish_data(DataPacket {
			payload: serde_json::to_vec(&payload)
			.context("failed to encode device output data message")?,
			topic: Some("device_output".to_string()),
			reliable: true,
			destination_identities: destinations,
			})
			.await
			.map_err(\|error\| anyhow!("failed to publish device output data message: {error}"))?;
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn_id,
			command_id_alias = %redact(command_id),
			command_code = %command_code,
			destination_count,
			"runtime helper device_output_sent"
			);
			Ok(())
			}

			async fn publish_reply_state(
			&self,
			call_id: &str,
			trace_id: &str,
			turn_id: &str,
			reply_playback_mode: &str,
			state: &str,
			seq: u64,
			) -> Result<()> {
			emit_activity(
			call_id,
			trace_id,
			Some(turn_id),
			"reply_state_send_started",
			"ok",
			None,
			None,
			json!({
			"state": state,
			"seq": seq,
			"replyPlaybackMode": reply_playback_mode,
			}),
			);
			let payload = serde_json::json!({
			"type": "reply_state",
			"schemaVersion": "1.0",
			"callId": call_id,
			"traceId": trace_id,
			"turnId": turn_id,
			"replyPlaybackMode": reply_playback_mode,
			"state": state,
			"seq": seq,
			"tsMs": current_time_millis(),
			});
			let destinations = self
			.device_output_destination_identity
			.as_ref()
			.filter(\|value\| !value.trim().is_empty())
			.map(\|value\| vec![ParticipantIdentity(value.trim().to_string())])
			.unwrap_or_default();
			let destination_count = destinations.len();
			let publish_result = self
			.room
			.local_participant()
			.publish_data(DataPacket {
			payload: serde_json::to_vec(&payload)
			.context("failed to encode reply state data message")?,
			topic: Some("combrabo_voice.reply_state".to_string()),
			reliable: true,
			destination_identities: destinations,
			})
			.await
			.map_err(\|error\| anyhow!("failed to publish reply state data message: {error}"));
			match publish_result {
			Ok(_) => {
			emit_activity(
			call_id,
			trace_id,
			Some(turn_id),
			"reply_state_send_finished",
			"ok",
			None,
			None,
			json!({
			"state": state,
			"seq": seq,
			"replyPlaybackMode": reply_playback_mode,
			"destinationCount": destination_count,
			}),
			);
			info!(
			call_id = %call_id,
			trace_id = %trace_id,
			turn_id = %turn_id,
			state = %state,
			seq,
			reply_playback_mode = %reply_playback_mode,
			destination_count,
			"runtime helper reply_state_sent"
			);
			Ok(())
			}
			Err(error) => {
			emit_activity(
			call_id,
			trace_id,
			Some(turn_id),
			"reply_state_send_failed",
			"failed",
			Some("REPLY_STATE_SEND_FAILED"),
			Some(true),
			json!({
			"state": state,
			"seq": seq,
			"replyPlaybackMode": reply_playback_mode,
			}),
			);
			Err(error)
			}
			}
			}

			async fn write_pcm_frame(&self, frame: &audio::PcmFrame) -> Result<()> {
			let audio_frame = AudioFrame {
			data: frame.data.as_slice().into(),