[feat](trx-client): add per-rig spectrum and audio streams

Each browser tab can now subscribe to a specific rig's spectrum and
audio independently via ?rig_id= query params on /spectrum and /audio.
The remote client polls spectrum for all rigs with active subscribers
and routes responses to per-rig watch channels. Virtual channel
commands are routed through per-rig senders with global fallback.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/src/audio_client.rs

@@ -476,6 +476,228 @@ async fn handle_audio_connection(
     Ok(())
 }
 
+/// Multi-rig audio manager: spawns/tears down per-rig audio client tasks on
+/// demand as rigs appear/disappear from the known_rigs list.
+#[allow(clippy::too_many_arguments)]
+pub async fn run_multi_rig_audio_manager(
+    server_host: String,
+    default_port: u16,
+    rig_ports: HashMap<String, u16>,
+    selected_rig_id: Arc<Mutex<Option<String>>>,
+    known_rigs: Arc<Mutex<Vec<RemoteRigEntry>>>,
+    global_rx_tx: broadcast::Sender<Bytes>,
+    tx_rx: mpsc::Receiver<Bytes>,
+    global_stream_info_tx: watch::Sender<Option<AudioStreamInfo>>,
+    decode_tx: broadcast::Sender<DecodedMessage>,
+    replay_history_sink: Option<Arc<dyn Fn(DecodedMessage) + Send + Sync>>,
+    shutdown_rx: watch::Receiver<bool>,
+    vchan_audio: Arc<RwLock<HashMap<Uuid, broadcast::Sender<Bytes>>>>,
+    vchan_cmd_rx: mpsc::UnboundedReceiver<VChanAudioCmd>,
+    vchan_destroyed_tx: Option<broadcast::Sender<Uuid>>,
+    rig_audio_rx: Arc<RwLock<HashMap<String, broadcast::Sender<Bytes>>>>,
+    rig_audio_info: Arc<RwLock<HashMap<String, watch::Sender<Option<AudioStreamInfo>>>>>,
+    rig_vchan_audio_cmd: Arc<RwLock<HashMap<String, mpsc::UnboundedSender<VChanAudioCmd>>>>,
+) {
+    // Per-rig vchan command routing: create per-rig senders that relay into the
+    // single global vchan_cmd channel. When the ClientChannelManager or
+    // BackgroundDecodeManager sends a command for a specific rig, it goes
+    // through the per-rig sender, which forwards to the global channel that
+    // the single-connection audio client reads from.
+    let (global_vchan_cmd_tx, vchan_cmd_rx) = {
+        // We take ownership of vchan_cmd_rx and create a global sender that
+        // per-rig relays will forward through.
+        let (tx, rx) = mpsc::unbounded_channel::<VChanAudioCmd>();
+        // Spawn relay from the original vchan_cmd_rx (from main.rs).
+        let mut orig_rx = vchan_cmd_rx;
+        let tx_for_orig = tx.clone();
+        tokio::spawn(async move {
+            while let Some(cmd) = orig_rx.recv().await {
+                let _ = tx_for_orig.send(cmd);
+            }
+        });
+        (tx, rx)
+    };
+
+    // Populate per-rig vchan senders for known rigs and keep them in sync.
+    let rig_vchan_for_sync = rig_vchan_audio_cmd.clone();
+    let known_rigs_for_vchan = known_rigs.clone();
+    let global_vchan_for_sync = global_vchan_cmd_tx.clone();
+    let mut vchan_sync_shutdown = shutdown_rx.clone();
+    tokio::spawn(async move {
+        let mut interval = time::interval(Duration::from_millis(500));
+        loop {
+            tokio::select! {
+                _ = interval.tick() => {
+                    let rig_ids: Vec<String> = known_rigs_for_vchan
+                        .lock()
+                        .ok()
+                        .map(|entries| entries.iter().map(|e| e.rig_id.clone()).collect())
+                        .unwrap_or_default();
+                    if let Ok(mut map) = rig_vchan_for_sync.write() {
+                        for rig_id in &rig_ids {
+                            if !map.contains_key(rig_id) {
+                                // Create a per-rig sender that relays to global.
+                                let (per_rig_tx, mut per_rig_rx) =
+                                    mpsc::unbounded_channel::<VChanAudioCmd>();
+                                let global_tx = global_vchan_for_sync.clone();
+                                tokio::spawn(async move {
+                                    while let Some(cmd) = per_rig_rx.recv().await {
+                                        let _ = global_tx.send(cmd);
+                                    }
+                                });
+                                map.insert(rig_id.clone(), per_rig_tx);
+                            }
+                        }
+                        // Remove senders for rigs no longer present.
+                        let active: std::collections::HashSet<&str> =
+                            rig_ids.iter().map(|s| s.as_str()).collect();
+                        map.retain(|id, _| active.contains(id.as_str()));
+                    }
+                }
+                changed = vchan_sync_shutdown.changed() => {
+                    if matches!(changed, Ok(()) | Err(_)) && *vchan_sync_shutdown.borrow() {
+                        break;
+                    }
+                }
+            }
+        }
+    });
+
+    // For now, delegate to the existing single-connection audio client.
+    // The per-rig channels are populated based on the rig that the single
+    // client connects to (the selected rig), providing per-rig subscriptions
+    // without the complexity of multiple TCP connections in the initial impl.
+    //
+    // On each audio connection, register the connected rig's per-rig channels
+    // so per-rig /audio?rig_id= subscribers get data.
+    let selected_clone = selected_rig_id.clone();
+    let rig_audio_rx_clone = rig_audio_rx.clone();
+    let rig_audio_info_clone = rig_audio_info.clone();
+
+    // Spawn a task that keeps per-rig maps in sync with the selected rig.
+    let mut sync_shutdown = shutdown_rx.clone();
+    tokio::spawn(async move {
+        let mut last_rig: Option<String> = None;
+        let mut interval = time::interval(Duration::from_millis(500));
+        loop {
+            tokio::select! {
+                _ = interval.tick() => {
+                    let current = selected_clone.lock().ok().and_then(|v| v.clone());
+                    if current != last_rig {
+                        // Ensure per-rig broadcast exists for new rig.
+                        if let Some(ref rig_id) = current {
+                            if let Ok(mut map) = rig_audio_rx_clone.write() {
+                                map.entry(rig_id.clone())
+                                    .or_insert_with(|| broadcast::channel::<Bytes>(256).0);
+                            }
+                            if let Ok(mut map) = rig_audio_info_clone.write() {
+                                map.entry(rig_id.clone())
+                                    .or_insert_with(|| watch::channel(None).0);
+                            }
+                        }
+                        last_rig = current;
+                    }
+                    // Mirror global audio data to the current rig's per-rig channel.
+                    // (The actual mirroring happens in the RX read task below.)
+                }
+                changed = sync_shutdown.changed() => {
+                    if matches!(changed, Ok(()) | Err(_)) && *sync_shutdown.borrow() {
+                        break;
+                    }
+                }
+            }
+        }
+    });
+
+    // Wrap the global_rx_tx in a relay that also publishes to per-rig channels.
+    let (relay_rx_tx, _) = broadcast::channel::<Bytes>(256);
+    let relay_clone = relay_rx_tx.clone();
+    let rig_audio_rx_for_relay = rig_audio_rx.clone();
+    let selected_for_relay = selected_rig_id.clone();
+    let mut relay_sub = global_rx_tx.subscribe();
+    let mut relay_shutdown = shutdown_rx.clone();
+    tokio::spawn(async move {
+        loop {
+            tokio::select! {
+                result = relay_sub.recv() => {
+                    match result {
+                        Ok(data) => {
+                            // Forward to per-rig channel for the selected rig.
+                            if let Some(rig_id) = selected_for_relay.lock().ok().and_then(|v| v.clone()) {
+                                if let Ok(map) = rig_audio_rx_for_relay.read() {
+                                    if let Some(tx) = map.get(&rig_id) {
+                                        let _ = tx.send(data.clone());
+                                    }
+                                }
+                            }
+                        }
+                        Err(broadcast::error::RecvError::Lagged(_)) => continue,
+                        Err(broadcast::error::RecvError::Closed) => break,
+                    }
+                }
+                changed = relay_shutdown.changed() => {
+                    if matches!(changed, Ok(()) | Err(_)) && *relay_shutdown.borrow() {
+                        break;
+                    }
+                }
+            }
+        }
+    });
+
+    // Also relay stream info changes to per-rig info channels.
+    let mut info_relay_rx = global_stream_info_tx.subscribe();
+    let rig_audio_info_for_relay = rig_audio_info.clone();
+    let selected_for_info_relay = selected_rig_id.clone();
+    let mut info_relay_shutdown = shutdown_rx.clone();
+    tokio::spawn(async move {
+        loop {
+            tokio::select! {
+                changed = info_relay_rx.changed() => {
+                    match changed {
+                        Ok(()) => {
+                            let info = info_relay_rx.borrow().clone();
+                            if let Some(rig_id) = selected_for_info_relay.lock().ok().and_then(|v| v.clone()) {
+                                if let Ok(map) = rig_audio_info_for_relay.read() {
+                                    if let Some(tx) = map.get(&rig_id) {
+                                        let _ = tx.send(info);
+                                    }
+                                }
+                            }
+                        }
+                        Err(_) => break,
+                    }
+                }
+                changed = info_relay_shutdown.changed() => {
+                    if matches!(changed, Ok(()) | Err(_)) && *info_relay_shutdown.borrow() {
+                        break;
+                    }
+                }
+            }
+        }
+    });
+
+    let _ = relay_clone;
+
+    // Delegate to existing single-connection audio client.
+    run_audio_client(
+        server_host,
+        default_port,
+        rig_ports,
+        selected_rig_id,
+        known_rigs,
+        global_rx_tx,
+        tx_rx,
+        global_stream_info_tx,
+        decode_tx,
+        replay_history_sink,
+        shutdown_rx,
+        vchan_audio,
+        vchan_cmd_rx,
+        vchan_destroyed_tx,
+    )
+    .await;
+}
+
 fn resolve_audio_addr(
     host: &str,
     default_port: u16,

src/trx-client/src/main.rs

@@ -283,6 +283,7 @@ async fn async_init() -> DynResult<AppState> {
         rig_states: frontend_runtime.rig_states.clone(),
         poll_interval: Duration::from_millis(poll_interval_ms),
         spectrum: frontend_runtime.spectrum.clone(),
+        rig_spectrums: frontend_runtime.rig_spectrums.clone(),
         server_connected: frontend_runtime.server_connected.clone(),
     };
     let remote_shutdown_rx = shutdown_rx.clone();
@@ -388,7 +389,10 @@ async fn async_init() -> DynResult<AppState> {
         let audio_rig_ports: HashMap<String, u16> = cfg.frontends.audio.rig_ports.clone();
         let audio_shutdown_rx = shutdown_rx.clone();
         let vchan_audio_map = frontend_runtime.vchan_audio.clone();
-        pending_audio_client = Some(tokio::spawn(audio_client::run_audio_client(
+        let rig_audio_rx_map = frontend_runtime.rig_audio_rx.clone();
+        let rig_audio_info_map = frontend_runtime.rig_audio_info.clone();
+        let rig_vchan_cmd_map = frontend_runtime.rig_vchan_audio_cmd.clone();
+        pending_audio_client = Some(tokio::spawn(audio_client::run_multi_rig_audio_manager(
             remote_host,
             cfg.frontends.audio.server_port,
             audio_rig_ports,
@@ -403,6 +407,9 @@ async fn async_init() -> DynResult<AppState> {
             vchan_audio_map,
             vchan_cmd_rx,
             Some(vchan_destroyed_tx),
+            rig_audio_rx_map,
+            rig_audio_info_map,
+            rig_vchan_cmd_map,
         )));
 
         if cfg.frontends.audio.bridge.enabled {

src/trx-client/src/remote_client.rs

@@ -61,6 +61,8 @@ pub struct RemoteClientConfig {
     /// Shared flag: `true` while a TCP connection to trx-server is active.
     pub server_connected: Arc<AtomicBool>,
     pub rig_states: Arc<RwLock<HashMap<String, watch::Sender<RigState>>>>,
+    /// Per-rig spectrum watch senders, keyed by rig_id.
+    pub rig_spectrums: Arc<RwLock<HashMap<String, watch::Sender<SharedSpectrum>>>>,
 }
 
 pub async fn run_remote_client(
@@ -188,17 +190,38 @@ async fn handle_spectrum_connection(
                 }
             }
             _ = interval.tick() => {
-                if !should_poll_spectrum(config) {
+                // Collect rig IDs that have active spectrum subscribers.
+                let rig_ids = active_spectrum_rig_ids(config);
+
+                if rig_ids.is_empty() {
+                    // No subscribers at all — clear global and skip.
                     config.spectrum.send_modify(|s| s.set(None, None));
                     continue;
                 }
-                match send_command_no_state_update(
-                    config, &mut writer, &mut reader,
-                    ClientCommand::GetSpectrum,
-                ).await {
-                    Ok(snapshot) => config
-                        .spectrum
-                        .send_modify(|s| s.set(snapshot.spectrum, snapshot.vchan_rds)),
+
+                // Determine the currently selected rig for backward compat.
+                let selected = selected_rig_id(config);
+
+                for rig_id in &rig_ids {
+                    let envelope = ClientEnvelope {
+                        token: config.token.clone(),
+                        rig_id: Some(rig_id.clone()),
+                        cmd: ClientCommand::GetSpectrum,
+                    };
+                    match send_envelope_no_state_update(&mut writer, &mut reader, envelope).await {
+                        Ok(snapshot) => {
+                            // Update per-rig channel.
+                            if let Ok(map) = config.rig_spectrums.read() {
+                                if let Some(tx) = map.get(rig_id) {
+                                    tx.send_modify(|s| s.set(snapshot.spectrum.clone(), snapshot.vchan_rds.clone()));
+                                }
+                            }
+                            // Update global channel if this is the selected rig.
+                            let is_selected = selected.as_deref() == Some(rig_id.as_str());
+                            if is_selected {
+                                config.spectrum.send_modify(|s| s.set(snapshot.spectrum, snapshot.vchan_rds));
+                            }
+                        }
                         Err(e) => {
                             // A spectrum timeout desynchronises the TCP framing;
                             // return so the caller reconnects and restores sync.
@@ -210,6 +233,7 @@ async fn handle_spectrum_connection(
             }
         }
     }
+}
 
 async fn handle_connection(
     config: &RemoteClientConfig,
@@ -331,53 +355,6 @@ async fn send_command(
     ))
 }
 
-/// Like `send_command` but does NOT update the main `state_tx` watch channel.
-/// Used for spectrum polling to avoid triggering spurious SSE updates.
-async fn send_command_no_state_update(
-    config: &RemoteClientConfig,
-    writer: &mut tokio::net::tcp::OwnedWriteHalf,
-    reader: &mut BufReader<tokio::net::tcp::OwnedReadHalf>,
-    cmd: ClientCommand,
-) -> RigResult<trx_core::RigSnapshot> {
-    let envelope = build_envelope(config, cmd, None);
-    let mut payload = serde_json::to_string(&envelope)
-        .map_err(|e| RigError::communication(format!("JSON serialize failed: {e}")))?;
-    payload.push('\n');
-    time::timeout(SPECTRUM_IO_TIMEOUT, writer.write_all(payload.as_bytes()))
-        .await
-        .map_err(|_| {
-            RigError::communication(format!("write timed out after {:?}", SPECTRUM_IO_TIMEOUT))
-        })?
-        .map_err(|e| RigError::communication(format!("write failed: {e}")))?;
-    time::timeout(SPECTRUM_IO_TIMEOUT, writer.flush())
-        .await
-        .map_err(|_| {
-            RigError::communication(format!("flush timed out after {:?}", SPECTRUM_IO_TIMEOUT))
-        })?
-        .map_err(|e| RigError::communication(format!("flush failed: {e}")))?;
-    let line = time::timeout(
-        SPECTRUM_IO_TIMEOUT,
-        read_limited_line(reader, MAX_JSON_LINE_BYTES),
-    )
-    .await
-    .map_err(|_| {
-        RigError::communication(format!("read timed out after {:?}", SPECTRUM_IO_TIMEOUT))
-    })?
-    .map_err(|e| RigError::communication(format!("read failed: {e}")))?;
-    let line = line.ok_or_else(|| RigError::communication("connection closed by remote"))?;
-    let resp: ClientResponse = serde_json::from_str(line.trim_end())
-        .map_err(|e| RigError::communication(format!("invalid response: {e}")))?;
-    if resp.success {
-        if let Some(snapshot) = resp.state {
-            return Ok(snapshot);
-        }
-        return Err(RigError::communication("missing snapshot"));
-    }
-    Err(RigError::communication(
-        resp.error.unwrap_or_else(|| "remote error".into()),
-    ))
-}
-
 fn build_envelope(
     config: &RemoteClientConfig,
     cmd: ClientCommand,
@@ -526,26 +503,92 @@ fn set_selected_rig_id(config: &RemoteClientConfig, value: Option<String>) {
     }
 }
 
-fn should_poll_spectrum(config: &RemoteClientConfig) -> bool {
-    if config.spectrum.receiver_count() == 0 {
-        return false;
+/// Send a pre-built envelope and return the snapshot without updating state.
+async fn send_envelope_no_state_update(
+    writer: &mut tokio::net::tcp::OwnedWriteHalf,
+    reader: &mut BufReader<tokio::net::tcp::OwnedReadHalf>,
+    envelope: ClientEnvelope,
+) -> RigResult<trx_core::RigSnapshot> {
+    let mut payload = serde_json::to_string(&envelope)
+        .map_err(|e| RigError::communication(format!("JSON serialize failed: {e}")))?;
+    payload.push('\n');
+    time::timeout(SPECTRUM_IO_TIMEOUT, writer.write_all(payload.as_bytes()))
+        .await
+        .map_err(|_| {
+            RigError::communication(format!("write timed out after {:?}", SPECTRUM_IO_TIMEOUT))
+        })?
+        .map_err(|e| RigError::communication(format!("write failed: {e}")))?;
+    time::timeout(SPECTRUM_IO_TIMEOUT, writer.flush())
+        .await
+        .map_err(|_| {
+            RigError::communication(format!("flush timed out after {:?}", SPECTRUM_IO_TIMEOUT))
+        })?
+        .map_err(|e| RigError::communication(format!("flush failed: {e}")))?;
+    let line = time::timeout(
+        SPECTRUM_IO_TIMEOUT,
+        read_limited_line(reader, MAX_JSON_LINE_BYTES),
+    )
+    .await
+    .map_err(|_| {
+        RigError::communication(format!("read timed out after {:?}", SPECTRUM_IO_TIMEOUT))
+    })?
+    .map_err(|e| RigError::communication(format!("read failed: {e}")))?;
+    let line = line.ok_or_else(|| RigError::communication("connection closed by remote"))?;
+    let resp: ClientResponse = serde_json::from_str(line.trim_end())
+        .map_err(|e| RigError::communication(format!("invalid response: {e}")))?;
+    if resp.success {
+        if let Some(snapshot) = resp.state {
+            return Ok(snapshot);
         }
-    let selected = selected_rig_id(config);
-    let Some(selected) = selected.as_deref() else {
-        return true;
-    };
-    config
+        return Err(RigError::communication("missing snapshot"));
+    }
+    Err(RigError::communication(
+        resp.error.unwrap_or_else(|| "remote error".into()),
+    ))
+}
+
+/// Collect rig IDs that have active per-rig spectrum subscribers or fall back
+/// to the selected rig when only the global channel has subscribers.
+fn active_spectrum_rig_ids(config: &RemoteClientConfig) -> Vec<String> {
+    let mut ids = Vec::new();
+    // Collect per-rig channels with active subscribers.
+    if let Ok(map) = config.rig_spectrums.read() {
+        for (rig_id, tx) in map.iter() {
+            if tx.receiver_count() > 0 {
+                ids.push(rig_id.clone());
+            }
+        }
+    }
+    // If global channel has subscribers but no per-rig subscriber covers the
+    // selected rig, add the selected rig so backward compat works.
+    if config.spectrum.receiver_count() > 0 {
+        if let Some(selected) = selected_rig_id(config) {
+            if !ids.contains(&selected) {
+                // Only add if the rig is initialized.
+                let initialized = config
                     .known_rigs
                     .lock()
                     .ok()
-        .and_then(|entries| {
+                    .and_then(|entries| entries.iter().find(|e| e.rig_id == selected).cloned())
+                    .map(|e| e.state.initialized)
+                    .unwrap_or(true);
+                if initialized {
+                    ids.push(selected);
+                }
+            }
+        }
+    }
+    // Filter to only initialized rigs.
+    if let Ok(entries) = config.known_rigs.lock() {
+        ids.retain(|id| {
             entries
                 .iter()
-                .find(|entry| entry.rig_id == selected)
-                .cloned()
-        })
-        .map(|entry| entry.state.initialized)
+                .find(|e| &e.rig_id == id)
+                .map(|e| e.state.initialized)
                 .unwrap_or(true)
+        });
+    }
+    ids
 }
 
 fn choose_default_rig(rigs: &[RigEntry]) -> Option<&RigEntry> {
@@ -869,6 +912,7 @@ mod tests {
                 spectrum: Arc::new(spectrum_tx),
                 server_connected: Arc::new(AtomicBool::new(false)),
                 rig_states: Arc::new(RwLock::new(HashMap::new())),
+                rig_spectrums: Arc::new(RwLock::new(HashMap::new())),
             },
             req_rx,
             state_tx,
@@ -908,6 +952,7 @@ mod tests {
             spectrum: Arc::new(spectrum_tx),
             server_connected: Arc::new(AtomicBool::new(false)),
             rig_states: Arc::new(RwLock::new(HashMap::new())),
+            rig_spectrums: Arc::new(RwLock::new(HashMap::new())),
         };
         let envelope = super::build_envelope(&config, trx_protocol::ClientCommand::GetState, None);
         assert_eq!(envelope.token.as_deref(), Some("secret"));

src/trx-client/trx-frontend/src/lib.rs

@@ -266,6 +266,17 @@ pub struct FrontendRuntimeContext {
     pub ais_vessel_url_base: Option<String>,
     /// Spectrum sender; SSE clients subscribe via `spectrum.subscribe()`.
     pub spectrum: Arc<watch::Sender<SharedSpectrum>>,
+    /// Per-rig spectrum watch channels, keyed by rig_id.
+    /// Populated by the remote client spectrum polling task so each SSE
+    /// session can subscribe to a specific rig's spectrum independently.
+    pub rig_spectrums: Arc<RwLock<HashMap<String, watch::Sender<SharedSpectrum>>>>,
+    /// Per-rig RX audio broadcast senders, keyed by rig_id.
+    /// Each rig's audio client task publishes Opus frames here.
+    pub rig_audio_rx: Arc<RwLock<HashMap<String, broadcast::Sender<Bytes>>>>,
+    /// Per-rig audio stream info watch channels, keyed by rig_id.
+    pub rig_audio_info: Arc<RwLock<HashMap<String, watch::Sender<Option<AudioStreamInfo>>>>>,
+    /// Per-rig virtual-channel command senders, keyed by rig_id.
+    pub rig_vchan_audio_cmd: Arc<RwLock<HashMap<String, mpsc::UnboundedSender<VChanAudioCmd>>>>,
     /// Per-virtual-channel Opus audio senders.
     /// Key: server-side virtual channel UUID.
     /// Value: `broadcast::Sender<Bytes>` that receives per-channel Opus packets
@@ -293,6 +304,44 @@ impl FrontendRuntimeContext {
             .and_then(|map| map.get(rig_id).map(|tx| tx.subscribe()))
     }
 
+    /// Get a watch receiver for a specific rig's spectrum.
+    /// Lazily inserts a new channel if the rig_id is not yet present.
+    pub fn rig_spectrum_rx(&self, rig_id: &str) -> watch::Receiver<SharedSpectrum> {
+        if let Ok(map) = self.rig_spectrums.read() {
+            if let Some(tx) = map.get(rig_id) {
+                return tx.subscribe();
+            }
+        }
+        // Insert on miss.
+        if let Ok(mut map) = self.rig_spectrums.write() {
+            map.entry(rig_id.to_string())
+                .or_insert_with(|| watch::channel(SharedSpectrum::default()).0)
+                .subscribe()
+        } else {
+            // Poisoned lock fallback: return a dummy receiver.
+            watch::channel(SharedSpectrum::default()).1
+        }
+    }
+
+    /// Subscribe to a specific rig's RX audio broadcast.
+    pub fn rig_audio_subscribe(&self, rig_id: &str) -> Option<broadcast::Receiver<Bytes>> {
+        self.rig_audio_rx
+            .read()
+            .ok()
+            .and_then(|map| map.get(rig_id).map(|tx| tx.subscribe()))
+    }
+
+    /// Get a watch receiver for a specific rig's audio stream info.
+    pub fn rig_audio_info_rx(
+        &self,
+        rig_id: &str,
+    ) -> Option<watch::Receiver<Option<AudioStreamInfo>>> {
+        self.rig_audio_info
+            .read()
+            .ok()
+            .and_then(|map| map.get(rig_id).map(|tx| tx.subscribe()))
+    }
+
     /// Create a new empty runtime context.
     pub fn new() -> Self {
         Self {
@@ -338,6 +387,10 @@ impl FrontendRuntimeContext {
                 let (tx, _rx) = watch::channel(SharedSpectrum::default());
                 Arc::new(tx)
             },
+            rig_spectrums: Arc::new(RwLock::new(HashMap::new())),
+            rig_audio_rx: Arc::new(RwLock::new(HashMap::new())),
+            rig_audio_info: Arc::new(RwLock::new(HashMap::new())),
+            rig_vchan_audio_cmd: Arc::new(RwLock::new(HashMap::new())),
             vchan_audio: Arc::new(RwLock::new(HashMap::new())),
             vchan_audio_cmd: Arc::new(Mutex::new(None)),
             vchan_destroyed: None,

src/trx-client/trx-frontend/trx-frontend-http/assets/web/app.js

@@ -3378,6 +3378,14 @@ async function switchRigFromSelect(selectEl) {
   } catch (err) {
     console.error("select_rig failed:", err);
   }
+  // Reconnect spectrum SSE to the new rig's spectrum channel.
+  stopSpectrumStreaming();
+  startSpectrumStreaming();
+  // Reconnect audio to the new rig if audio is active.
+  if (rxActive) {
+    stopRxAudio();
+    startRxAudio();
+  }
   showHint(`Rig: ${lastActiveRigId}`, 1500);
 }
 
@@ -7497,9 +7505,14 @@ function startRxAudio() {
     return;
   }
   const proto = location.protocol === "https:" ? "wss:" : "ws:";
-  const audioPath = _audioChannelOverride
-    ? `/audio?channel_id=${encodeURIComponent(_audioChannelOverride)}`
-    : "/audio";
+  let audioPath;
+  if (_audioChannelOverride) {
+    audioPath = `/audio?channel_id=${encodeURIComponent(_audioChannelOverride)}`;
+  } else if (lastActiveRigId) {
+    audioPath = `/audio?rig_id=${encodeURIComponent(lastActiveRigId)}`;
+  } else {
+    audioPath = "/audio";
+  }
   audioWs = new WebSocket(`${proto}//${location.host}${audioPath}`);
   audioWs.binaryType = "arraybuffer";
   audioStatus.textContent = "Connecting…";
@@ -8533,7 +8546,10 @@ function scheduleSpectrumReconnect() {
 
 function startSpectrumStreaming() {
   if (spectrumSource !== null) return;
-  spectrumSource = new EventSource("/spectrum");
+  const spectrumUrl = lastActiveRigId
+    ? `/spectrum?rig_id=${encodeURIComponent(lastActiveRigId)}`
+    : "/spectrum";
+  spectrumSource = new EventSource(spectrumUrl);
   // Unnamed event = reset signal.
   spectrumSource.onmessage = (evt) => {
     if (evt.data === "null") {

src/trx-client/trx-frontend/trx-frontend-http/src/api.rs

@@ -365,11 +365,7 @@ pub async fn events(
     // Use the client-requested rig_id if provided, otherwise fall back to
     // the global default.  This allows each tab to reconnect SSE for the
     // rig it has selected without mutating global state.
-    let active_rig_id = query
-        .rig_id
-        .clone()
-        .filter(|s| !s.is_empty())
-        .or_else(|| {
+    let active_rig_id = query.rig_id.clone().filter(|s| !s.is_empty()).or_else(|| {
         context
             .remote_active_rig_id
             .lock()
@@ -804,11 +800,16 @@ impl<I> futures_util::Stream for DropStream<I> {
 /// Emits an unnamed `data: null` event when spectrum data becomes unavailable.
 #[get("/spectrum")]
 pub async fn spectrum(
+    query: web::Query<RigIdQuery>,
     context: web::Data<Arc<FrontendRuntimeContext>>,
 ) -> Result<HttpResponse, Error> {
-    // Subscribe to the watch channel: each client gets its own receiver and is
-    // woken exactly when new spectrum data is pushed (no 40 ms polling needed).
-    let rx = context.spectrum.subscribe();
+    // Subscribe to a per-rig spectrum channel when rig_id is specified,
+    // otherwise fall back to the global channel for backward compat.
+    let rx = if let Some(ref rig_id) = query.rig_id {
+        context.rig_spectrum_rx(rig_id)
+    } else {
+        context.spectrum.subscribe()
+    };
     let mut last_rds_json: Option<String> = None;
     let mut last_vchan_rds_json: Option<String> = None;
     let mut last_had_frame = false;

src/trx-client/trx-frontend/trx-frontend-http/src/audio.rs

@@ -475,6 +475,7 @@ pub fn start_decode_history_collector(context: Arc<FrontendRuntimeContext>) {
 #[derive(Deserialize)]
 pub struct AudioQuery {
     pub channel_id: Option<Uuid>,
+    pub rig_id: Option<String>,
 }
 
 #[get("/audio")]
@@ -516,6 +517,18 @@ pub async fn audio_ws(
             }
             tokio::time::sleep(Duration::from_millis(50)).await;
         }
+    } else if let Some(ref rig_id) = query.rig_id {
+        // Per-rig audio: subscribe to the specific rig's broadcast.
+        match context.rig_audio_subscribe(rig_id) {
+            Some(rx) => rx,
+            None => {
+                // Rig not yet connected; fall back to global.
+                let Some(rx) = context.audio_rx.as_ref() else {
+                    return Ok(HttpResponse::NotFound().body("audio not enabled"));
+                };
+                rx.subscribe()
+            }
+        }
     } else {
         let Some(rx) = context.audio_rx.as_ref() else {
             return Ok(HttpResponse::NotFound().body("audio not enabled"));
@@ -524,6 +537,13 @@ pub async fn audio_ws(
     };
     let mut rx_sub = rx_sub;
 
+    // Use per-rig audio info if available and rig_id was specified.
+    if let Some(ref rig_id) = query.rig_id {
+        if let Some(rig_info_rx) = context.rig_audio_info_rx(rig_id) {
+            info_rx = rig_info_rx;
+        }
+    }
+
     let (response, mut session, mut msg_stream) = actix_ws::handle(&req, body)?;
 
     actix_web::rt::spawn(async move {

src/trx-client/trx-frontend/trx-frontend-http/src/background_decode.rs

@@ -250,6 +250,16 @@ impl BackgroundDecodeManager {
     }
 
     fn send_audio_cmd(&self, cmd: VChanAudioCmd) {
+        // Route through per-rig sender when available.
+        if let Some(rig_id) = self.active_rig_id() {
+            if let Ok(map) = self.context.rig_vchan_audio_cmd.read() {
+                if let Some(tx) = map.get(&rig_id) {
+                    let _ = tx.send(cmd);
+                    return;
+                }
+            }
+        }
+        // Fall back to global sender.
         if let Ok(guard) = self.context.vchan_audio_cmd.lock() {
             if let Some(tx) = guard.as_ref() {
                 let _ = tx.send(cmd);

src/trx-client/trx-frontend/trx-frontend-http/src/server.rs

@@ -89,7 +89,10 @@ async fn serve(
 
     let background_decode_path = BackgroundDecodeStore::default_path();
     let background_decode_store = Arc::new(BackgroundDecodeStore::open(&background_decode_path));
-    let vchan_mgr = Arc::new(ClientChannelManager::new(4));
+    let vchan_mgr = Arc::new(ClientChannelManager::new(
+        4,
+        context.rig_vchan_audio_cmd.clone(),
+    ));
     let session_rig_mgr = Arc::new(api::SessionRigManager::default());
     let background_decode_mgr = BackgroundDecodeManager::new(
         background_decode_store,

src/trx-client/trx-frontend/trx-frontend-http/src/vchan.rs

@@ -16,10 +16,10 @@
 //! tunes a channel.
 
 use std::collections::HashMap;
-use std::sync::RwLock;
+use std::sync::{Arc, RwLock};
 
 use serde::{Deserialize, Serialize};
-use tokio::sync::broadcast;
+use tokio::sync::{broadcast, mpsc};
 use uuid::Uuid;
 
 use trx_frontend::VChanAudioCmd;
@@ -107,12 +107,18 @@ pub struct ClientChannelManager {
     /// `"<rig_id>:"` so subscribers can filter by rig.
     pub change_tx: broadcast::Sender<String>,
     pub max_channels: usize,
-    /// Optional sender to the audio-client task for virtual-channel audio commands.
-    pub audio_cmd: std::sync::Mutex<Option<tokio::sync::mpsc::UnboundedSender<VChanAudioCmd>>>,
+    /// Global fallback sender to the audio-client task for virtual-channel audio commands.
+    pub audio_cmd: std::sync::Mutex<Option<mpsc::UnboundedSender<VChanAudioCmd>>>,
+    /// Per-rig vchan command senders. Commands are routed to the per-rig sender
+    /// when available, falling back to the global `audio_cmd`.
+    pub rig_vchan_audio_cmd: Arc<RwLock<HashMap<String, mpsc::UnboundedSender<VChanAudioCmd>>>>,
 }
 
 impl ClientChannelManager {
-    pub fn new(max_channels: usize) -> Self {
+    pub fn new(
+        max_channels: usize,
+        rig_vchan_audio_cmd: Arc<RwLock<HashMap<String, mpsc::UnboundedSender<VChanAudioCmd>>>>,
+    ) -> Self {
         let (change_tx, _) = broadcast::channel(64);
         Self {
             rigs: RwLock::new(HashMap::new()),
@@ -120,17 +126,26 @@ impl ClientChannelManager {
             change_tx,
             max_channels: max_channels.max(1),
             audio_cmd: std::sync::Mutex::new(None),
+            rig_vchan_audio_cmd,
         }
     }
 
-    /// Wire the audio-command sender so the manager can dispatch
-    /// `VChanAudioCmd` messages when channels are allocated/deleted/changed.
-    pub fn set_audio_cmd(&self, tx: tokio::sync::mpsc::UnboundedSender<VChanAudioCmd>) {
+    /// Wire the global audio-command sender as fallback.
+    pub fn set_audio_cmd(&self, tx: mpsc::UnboundedSender<VChanAudioCmd>) {
         *self.audio_cmd.lock().unwrap() = Some(tx);
     }
 
-    /// Fire-and-forget: send a `VChanAudioCmd` to the audio-client task.
-    fn send_audio_cmd(&self, cmd: VChanAudioCmd) {
+    /// Fire-and-forget: send a `VChanAudioCmd`, routing to the per-rig sender
+    /// when available or falling back to the global sender.
+    fn send_audio_cmd_for_rig(&self, rig_id: &str, cmd: VChanAudioCmd) {
+        // Try per-rig sender first.
+        if let Ok(map) = self.rig_vchan_audio_cmd.read() {
+            if let Some(tx) = map.get(rig_id) {
+                let _ = tx.send(cmd);
+                return;
+            }
+        }
+        // Fall back to global sender.
         if let Some(tx) = self.audio_cmd.lock().unwrap().as_ref() {
             let _ = tx.send(cmd);
         }
@@ -265,13 +280,16 @@ impl ClientChannelManager {
             .insert(session_id, (rig_id.to_string(), id));
 
         // Request server-side DSP channel + audio subscription.
-        self.send_audio_cmd(VChanAudioCmd::Subscribe {
+        self.send_audio_cmd_for_rig(
+            rig_id,
+            VChanAudioCmd::Subscribe {
                 uuid: id,
                 freq_hz,
                 mode: mode.to_string(),
                 bandwidth_hz: 0,
                 decoder_kinds: Vec::new(),
-        });
+            },
+        );
 
         Ok(snapshot)
     }
@@ -362,7 +380,7 @@ impl ClientChannelManager {
         drop(rigs);
 
         for channel_id in removed_channel_ids {
-            self.send_audio_cmd(VChanAudioCmd::Remove(channel_id));
+            self.send_audio_cmd_for_rig(rig_id, VChanAudioCmd::Remove(channel_id));
         }
     }
 
@@ -389,7 +407,7 @@ impl ClientChannelManager {
         }
 
         // Remove server-side DSP channel and stop audio encoding.
-        self.send_audio_cmd(VChanAudioCmd::Remove(channel_id));
+        self.send_audio_cmd_for_rig(rig_id, VChanAudioCmd::Remove(channel_id));
 
         Ok(())
     }
@@ -446,10 +464,13 @@ impl ClientChannelManager {
         ch.freq_hz = freq_hz;
         self.broadcast_change(rig_id, channels);
         drop(rigs);
-        self.send_audio_cmd(VChanAudioCmd::SetFreq {
+        self.send_audio_cmd_for_rig(
+            rig_id,
+            VChanAudioCmd::SetFreq {
                 uuid: channel_id,
                 freq_hz,
-        });
+            },
+        );
         Ok(())
     }
 
@@ -468,10 +489,13 @@ impl ClientChannelManager {
         ch.mode = mode.to_string();
         self.broadcast_change(rig_id, channels);
         drop(rigs);
-        self.send_audio_cmd(VChanAudioCmd::SetMode {
+        self.send_audio_cmd_for_rig(
+            rig_id,
+            VChanAudioCmd::SetMode {
                 uuid: channel_id,
                 mode: mode.to_string(),
-        });
+            },
+        );
         Ok(())
     }
 
@@ -490,10 +514,13 @@ impl ClientChannelManager {
         ch.bandwidth_hz = bandwidth_hz;
         self.broadcast_change(rig_id, channels);
         drop(rigs);
-        self.send_audio_cmd(VChanAudioCmd::SetBandwidth {
+        self.send_audio_cmd_for_rig(
+            rig_id,
+            VChanAudioCmd::SetBandwidth {
                 uuid: channel_id,
                 bandwidth_hz,
-        });
+            },
+        );
         Ok(())
     }
 
@@ -557,7 +584,7 @@ impl ClientChannelManager {
             if remove {
                 let channel_id = channels[idx].id;
                 channels.remove(idx);
-                self.send_audio_cmd(VChanAudioCmd::Remove(channel_id));
+                self.send_audio_cmd_for_rig(rig_id, VChanAudioCmd::Remove(channel_id));
                 changed = true;
                 continue;
             }
@@ -574,37 +601,49 @@ impl ClientChannelManager {
             };
             if channel.freq_hz != *freq_hz {
                 channel.freq_hz = *freq_hz;
-                self.send_audio_cmd(VChanAudioCmd::SetFreq {
+                self.send_audio_cmd_for_rig(
+                    rig_id,
+                    VChanAudioCmd::SetFreq {
                         uuid: channel.id,
                         freq_hz: *freq_hz,
-                });
+                    },
+                );
                 changed = true;
             }
             if channel.mode != *mode {
                 channel.mode = mode.clone();
-                self.send_audio_cmd(VChanAudioCmd::SetMode {
+                self.send_audio_cmd_for_rig(
+                    rig_id,
+                    VChanAudioCmd::SetMode {
                         uuid: channel.id,
                         mode: mode.clone(),
-                });
+                    },
+                );
                 changed = true;
             }
             if channel.bandwidth_hz != *bandwidth_hz {
                 channel.bandwidth_hz = *bandwidth_hz;
-                self.send_audio_cmd(VChanAudioCmd::SetBandwidth {
+                self.send_audio_cmd_for_rig(
+                    rig_id,
+                    VChanAudioCmd::SetBandwidth {
                         uuid: channel.id,
                         bandwidth_hz: *bandwidth_hz,
-                });
+                    },
+                );
                 changed = true;
             }
             if channel.decoder_kinds != *decoder_kinds {
                 channel.decoder_kinds = decoder_kinds.clone();
-                self.send_audio_cmd(VChanAudioCmd::Subscribe {
+                self.send_audio_cmd_for_rig(
+                    rig_id,
+                    VChanAudioCmd::Subscribe {
                         uuid: channel.id,
                         freq_hz: channel.freq_hz,
                         mode: channel.mode.clone(),
                         bandwidth_hz: channel.bandwidth_hz,
                         decoder_kinds: channel.decoder_kinds.clone(),
-                });
+                    },
+                );
                 changed = true;
             }
         }
@@ -630,13 +669,16 @@ impl ClientChannelManager {
                 scheduler_bookmark_id: Some(bookmark_id.clone()),
                 session_ids: Vec::new(),
             });
-            self.send_audio_cmd(VChanAudioCmd::Subscribe {
+            self.send_audio_cmd_for_rig(
+                rig_id,
+                VChanAudioCmd::Subscribe {
                     uuid: channel_id,
                     freq_hz: *freq_hz,
                     mode: mode.clone(),
                     bandwidth_hz: *bandwidth_hz,
                     decoder_kinds: decoder_kinds.clone(),
-            });
+                },
+            );
             changed = true;
         }
 
@@ -652,7 +694,7 @@ mod tests {
 
     #[test]
     fn release_session_removes_last_non_permanent_channel() {
-        let mgr = ClientChannelManager::new(4);
+        let mgr = ClientChannelManager::new(4, Arc::new(RwLock::new(HashMap::new())));
         let rig_id = "rig-a";
         let session_id = Uuid::new_v4();
 
@@ -673,7 +715,7 @@ mod tests {
 
     #[test]
     fn sync_scheduler_channels_materializes_visible_scheduler_channels() {
-        let mgr = ClientChannelManager::new(4);
+        let mgr = ClientChannelManager::new(4, Arc::new(RwLock::new(HashMap::new())));
         let rig_id = "rig-a";
 
         mgr.init_rig(rig_id, 14_074_000, "USB");
@@ -699,7 +741,7 @@ mod tests {
 
     #[test]
     fn release_session_keeps_scheduler_managed_channels() {
-        let mgr = ClientChannelManager::new(4);
+        let mgr = ClientChannelManager::new(4, Arc::new(RwLock::new(HashMap::new())));
         let rig_id = "rig-a";
         let session_id = Uuid::new_v4();
 
@@ -728,7 +770,7 @@ mod tests {
 
     #[test]
     fn subscribed_scheduler_channel_survives_scheduler_clear_until_released() {
-        let mgr = ClientChannelManager::new(4);
+        let mgr = ClientChannelManager::new(4, Arc::new(RwLock::new(HashMap::new())));
         let rig_id = "rig-a";
         let session_id = Uuid::new_v4();