feat: FlexRadio CWX CW keyer (send/stop/speed) — no WinKeyer/SmartCAT needed

Adds a third CW engine alongside WinKeyer and Icom CI-V: FlexRadio's CWX keyer
over the existing SmartSDR CAT connection.

- cat.FlexController: SendCW (cwx send), StopCW (cwx clear); flex.go implements
  them, escaping the quoted text form. Speed reuses SetCWSpeed (cw wpm).
- App bindings FlexSendCW/FlexStopCW/FlexSetKeySpeed via FlexDo.
- Frontend: cwSource gains 'flex'; macros/auto-call/<LOGQSO>/send-on-type route to
  Flex when the CAT backend is a Flex (estimate-based timing like Icom, no busy
  echo). Keyer panel shows 'Flex CWX' + ready/offline; Settings adds the engine
  option with a CAT-backend guard.

Core send/stop/speed first; type-ahead buffer + mid-send backspace (cwx delete)
to follow.

app.go

@@ -10359,6 +10359,36 @@ func (a *App) IcomSendCW(text string) error {
 	return err
 }
 
+// FlexSendCW keys a CW message through the FlexRadio CWX keyer (SmartSDR), so a
+// Flex needs no WinKeyer / SmartCAT. Text is already variable-resolved by the UI.
+func (a *App) FlexSendCW(text string) error {
+	if a.cat == nil {
+		return fmt.Errorf("cat not initialized")
+	}
+	err := a.cat.FlexDo(func(fc cat.FlexController) error { return fc.SendCW(text) })
+	if err != nil {
+		applog.Printf("flex cw: FlexSendCW(%q) failed: %v", text, err)
+	}
+	return err
+}
+
+// FlexStopCW clears the CWX buffer, aborting whatever is being keyed.
+func (a *App) FlexStopCW() error {
+	if a.cat == nil {
+		return fmt.Errorf("cat not initialized")
+	}
+	return a.cat.FlexDo(func(fc cat.FlexController) error { return fc.StopCW() })
+}
+
+// FlexSetKeySpeed sets the CW keyer speed in WPM (the CWX keyer uses the radio's
+// CW speed).
+func (a *App) FlexSetKeySpeed(wpm int) error {
+	if a.cat == nil {
+		return fmt.Errorf("cat not initialized")
+	}
+	return a.cat.FlexDo(func(fc cat.FlexController) error { return fc.SetCWSpeed(wpm) })
+}
+
 // IcomStopCW aborts the CW message currently being sent.
 func (a *App) IcomStopCW() error {
 	if a.cat == nil {

frontend/src/App.tsx

@@ -36,6 +36,7 @@ import {
   GetWinkeyerSettings, SaveWinkeyerSettings, ListSerialPorts, GetWinkeyerStatus,
   WinkeyerConnect, WinkeyerDisconnect, WinkeyerSend, WinkeyerStop, WinkeyerSetSpeed, WinkeyerBackspace,
   IcomSendCW, IcomStopCW, IcomSetKeySpeed, IcomSetBreakIn, GetIcomState,
+  FlexSendCW, FlexStopCW, FlexSetKeySpeed,
   GetDVKMessages, GetDVKStatus, DVKPlay, DVKStop,
   StartCWDecoder, StopCWDecoder, SetCWDecoderPitch,
   ChatAvailable, GetChatHistory, SendChatMessage, GetOnlineOperators,
@@ -775,7 +776,7 @@ export default function App() {
   // CI-V 0x17 (no extra hardware — sends over the CAT connection). Macros,
   // auto-call and <LOGQSO> are shared; only the transport differs.
   const [wkEngine, setWkEngine] = useState<string>('winkeyer');
-  const cwSource: 'winkeyer' | 'icom' = wkEngine === 'icom' ? 'icom' : 'winkeyer';
+  const cwSource: 'winkeyer' | 'icom' | 'flex' = wkEngine === 'icom' ? 'icom' : wkEngine === 'flex' ? 'flex' : 'winkeyer';
   const cwSourceRef = useRef(cwSource);
   useEffect(() => { cwSourceRef.current = cwSource; }, [cwSource]);
   // CW break-in (0=OFF, 1=SEMI, 2=FULL) — must be on for the rig's 0x17 keyer to
@@ -804,7 +805,9 @@ export default function App() {
   const wkBusyRef = useRef(false); // live "keyer is sending" flag, for the <LOGQSO> wait-then-log
   useEffect(() => { wkBusyRef.current = wkStatus.busy; }, [wkStatus.busy]);
   useEffect(() => {
-    const connected = cwSource === 'icom' ? (catState.backend === 'icom' && catState.connected) : wkStatus.connected;
+    const connected = cwSource === 'icom' ? (catState.backend === 'icom' && catState.connected)
+      : cwSource === 'flex' ? (catState.backend === 'flex' && catState.connected)
+      : wkStatus.connected;
     wkActiveRef.current = wkEnabled && connected;
   }, [wkEnabled, wkStatus.connected, cwSource, catState.backend, catState.connected]);
   useEffect(() => { wkEscClearsRef.current = wkEscClears; }, [wkEscClears]);
@@ -2036,7 +2039,7 @@ export default function App() {
       setWkMacros((s.macros ?? []) as WKMacro[]);
       setWkEscClears(s.esc_clears_call !== false);
       setWkSendOnType(!!s.send_on_type);
-      setWkEngine(s.engine === 'icom' ? 'icom' : 'winkeyer');
+      setWkEngine(s.engine === 'icom' ? 'icom' : s.engine === 'flex' ? 'flex' : 'winkeyer');
     } catch { /* keyer not configured */ }
   }, []);
 
@@ -2134,11 +2137,13 @@ export default function App() {
     const keyed = resolved ? resolved + ' ' : resolved;
     const doLog = /<LOGQSO>/i.test(rawText); // resolveCW strips the token (unknown var → "")
     const sleep = (ms: number) => new Promise((r) => window.setTimeout(r, ms));
-    if (cwSourceRef.current === 'icom') {
+    if (cwSourceRef.current === 'icom' || cwSourceRef.current === 'flex') {
-      // The rig's keyer gives no busy echo back, so show the text we sent and,
+      // The rig keyer (Icom 0x17 / Flex CWX) gives no busy echo we track, so show
-      // for <LOGQSO>, wait the estimated send duration before logging.
+      // the text we sent and, for <LOGQSO>, wait the estimated send duration
+      // before logging.
       setWkSent(resolved);
-      await IcomSendCW(keyed).catch((e) => setError(String(e?.message ?? e)));
+      const sendFn = cwSourceRef.current === 'flex' ? FlexSendCW : IcomSendCW;
+      await sendFn(keyed).catch((e) => setError(String(e?.message ?? e)));
       if (doLog) { await sleep(Math.round(estimateCwMs(resolved, wkWpm)) + 600); void save(); }
       return;
     }
@@ -2174,7 +2179,7 @@ export default function App() {
       // the wait at the ESTIMATED send time (not the busy flag alone): over a
       // remote/serial-over-IP link the "busy" status lags badly and stays stuck
       // true for tens of seconds, which made the next CQ fire ~120s late.
-      if (cwSourceRef.current === 'icom') {
+      if (cwSourceRef.current === 'icom' || cwSourceRef.current === 'flex') {
         await sleep(Math.round(estimateCwMs(resolveCW(m.text), wkWpm)) + 300);
       } else {
         const capMs = Math.round(estimateCwMs(resolveCW(m.text), wkWpm) * 1.4) + 2500;
@@ -2212,7 +2217,10 @@ export default function App() {
     writeUiPref('opslog.wkAutoCallSecs', String(v));
   }
   // send-on-type: key the typed chars verbatim (no variable substitution).
-  function wkSendRaw(chars: string) { WinkeyerSend(chars).catch(() => {}); }
+  function wkSendRaw(chars: string) {
+    if (cwSourceRef.current === 'flex') { FlexSendCW(chars).catch(() => {}); return; }
+    WinkeyerSend(chars).catch(() => {});
+  }
   function wkBackspace() { WinkeyerBackspace().catch(() => {}); }
   function wkToggleSendOnType(on: boolean) { setWkSendOnType(on); saveWk({ send_on_type: on }); }
 
@@ -4406,8 +4414,8 @@ export default function App() {
           {wkEnabled && (
             <div className="w-[380px] shrink-0 min-h-0">
               <WinkeyerPanel
-                status={cwSource === 'icom'
+                status={cwSource === 'icom' || cwSource === 'flex'
-                  ? { connected: catState.backend === 'icom' && catState.connected, busy: false, wpm: wkWpm, version: 0, port: 'CI-V' }
+                  ? { connected: catState.backend === cwSource && catState.connected, busy: false, wpm: wkWpm, version: 0, port: cwSource === 'flex' ? 'CWX' : 'CI-V' }
                   : wkStatus}
                 ports={wkPorts}
                 port={wkPort}
@@ -4424,11 +4432,15 @@ export default function App() {
                 onSetSpeed={(w) => {
                   setWkWpm(w); saveWk({ wpm: w });
                   if (cwSource === 'icom') IcomSetKeySpeed(w).catch(() => {});
+                  else if (cwSource === 'flex') FlexSetKeySpeed(w).catch(() => {});
                   else WinkeyerSetSpeed(w).catch(() => {});
                 }}
                 onSend={wkSend}
                 onSendMacro={wkSendMacro}
-                onStop={() => { stopAutoCall(); if (cwSource === 'icom') IcomStopCW().catch(() => {}); else WinkeyerStop().catch(() => {}); }}
+                onStop={() => { stopAutoCall();
+                  if (cwSource === 'icom') IcomStopCW().catch(() => {});
+                  else if (cwSource === 'flex') FlexStopCW().catch(() => {});
+                  else WinkeyerStop().catch(() => {}); }}
                 onClose={() => wkSetEnabled(false)}
                 sendOnType={wkSendOnType}
                 onToggleSendOnType={wkToggleSendOnType}

frontend/src/components/SettingsModal.tsx

@@ -2807,6 +2807,7 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
                 <SelectContent>
                   <SelectItem value="winkeyer">WinKeyer (serial)</SelectItem>
                   <SelectItem value="icom">Icom CI-V (rig keyer)</SelectItem>
+                  <SelectItem value="flex">FlexRadio (CWX)</SelectItem>
                   <SelectItem value="tci" disabled>TCI (coming soon)</SelectItem>
                 </SelectContent>
               </Select>
@@ -2837,6 +2838,26 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
                 </div>
               </div>
             </>
+          ) : wk.engine === 'flex' ? (
+            <>
+              <p className="text-xs text-muted-foreground -mt-2">
+                FlexRadio keys CW through the radio's <strong>CWX</strong> keyer over the existing SmartSDR CAT connection — no WinKeyer or SmartCAT needed. It reuses the connection set in Settings → CAT, so there's nothing else to wire up here. Put a slice in CW mode. Only the speed is set from here; weight, sidetone and break-in are configured on the radio (break-in must be on for CW to actually transmit).
+              </p>
+              {(!catCfg.enabled || catCfg.backend !== 'flex') && (
+                <p className="text-xs font-medium text-warning -mt-1 flex items-start gap-1.5">
+                  <span aria-hidden>⚠</span>
+                  <span>
+                    Your CAT backend is set to <strong>{catCfg.enabled ? (catCfg.backend || 'none') : 'disabled'}</strong>. Flex CWX needs the CAT backend set to <strong>FlexRadio</strong> and connected — change it under Settings → CAT interface, otherwise sending CW will fail.
+                  </span>
+                </p>
+              )}
+              <div className="grid grid-cols-4 gap-3">
+                <div className="space-y-1">
+                  <Label>Speed (WPM)</Label>
+                  <Input type="number" min={6} max={48} value={wk.wpm} onChange={(e) => setWkField({ wpm: num(e.target.value, 25) })} className="font-mono" />
+                </div>
+              </div>
+            </>
           ) : (
             <>
               <div className="grid grid-cols-4 gap-3">

frontend/src/components/WinkeyerPanel.tsx

@@ -26,7 +26,7 @@ interface Props {
   wpm: number;
   macros: WKMacro[];
   sent: string; // text echoed back by the keyer as it transmits
-  source: 'winkeyer' | 'icom';               // CW output engine (chosen in Settings → CW Keyer)
+  source: 'winkeyer' | 'icom' | 'flex';      // CW output engine (chosen in Settings → CW Keyer)
   breakIn?: number;                          // Icom CW break-in: 0=OFF, 1=SEMI, 2=FULL
   onSetBreakIn?: (mode: number) => void;
   onSelectPort: (p: string) => void;
@@ -101,14 +101,16 @@ export function WinkeyerPanel({
         <Radio className="size-4 text-primary shrink-0" />
         {/* CW output engine (chosen in Settings → CW Keyer). */}
         <span className="text-xs font-semibold uppercase tracking-wider text-muted-foreground shrink-0">
-          {source === 'icom' ? 'Icom CW' : 'WinKeyer'}
+          {source === 'icom' ? 'Icom CW' : source === 'flex' ? 'Flex CWX' : 'WinKeyer'}
         </span>
         <span className={cn('size-2 rounded-full', connected ? (status.busy ? 'bg-warning animate-pulse' : 'bg-success') : 'bg-muted-foreground/40')}
           title={connected ? (status.busy ? t('wkp.sending') : t('wkp.connectedV', { version: status.version })) : t('wkp.disconnected')} />
         <div className="flex-1" />
-        {source === 'icom' ? (
+        {source === 'icom' || source === 'flex' ? (
           <span className="text-[11px] font-medium text-muted-foreground">
-            {connected ? t('wkp.civReady') : t('wkp.civOffline')}
+            {source === 'flex'
+              ? (connected ? t('wkp.cwxReady') : t('wkp.cwxOffline'))
+              : (connected ? t('wkp.civReady') : t('wkp.civOffline'))}
           </span>
         ) : !connected ? (
           <>
@@ -183,7 +185,7 @@ export function WinkeyerPanel({
           <div className="flex flex-col flex-1 min-w-0">
             <Label className="mb-1 h-3.5 text-xs flex items-center gap-2">
               {t('wkp.cwText')}
-              {source === 'winkeyer' && (
+              {(source === 'winkeyer' || source === 'flex') && (
                 <label className="flex items-center gap-1 text-[10px] font-normal cursor-pointer text-muted-foreground"
                   title={t('wkp.sendOnTypeHint')}>
                   <input type="checkbox" className="accent-primary" checked={sendOnType}

frontend/src/lib/i18n.tsx

@@ -275,7 +275,7 @@ const en: Dict = {
   'adx.introPart1': 'Every ADIF 3.1.7 field not shown in the other tabs. Pick a field to add it, or type a custom/vendor tag (e.g. ', 'adx.introPart2': '). Stored losslessly and exported in the ', 'adx.fullMode': 'full', 'adx.introPart3': ' ADIF mode.', 'adx.addFieldPh': 'Add ADIF field…', 'adx.showDeprecated': 'Show deprecated', 'adx.noExtra': 'No extra ADIF fields. Use the picker above to add one.', 'adx.deprecated': 'deprecated', 'adx.intl': 'intl', 'adx.nonStandard': 'non-standard', 'adx.removeField': 'Remove field',
   // Hardware panels (winkeyer / dvk / antgenius / flex / icom)
   'wkp.sending': 'Sending…', 'wkp.connectedV': 'Connected (v{version})', 'wkp.disconnected': 'Disconnected', 'wkp.comPort': 'COM port', 'wkp.noPorts': 'No ports', 'wkp.refreshPorts': 'Refresh ports', 'wkp.connect': 'Connect', 'wkp.disconnect': 'Disconnect', 'wkp.hide': 'Hide / disable WinKeyer',
-  'wkp.sourceHint': 'CW output: WK = WinKeyer hardware · CI-V = the Icom rig’s own keyer (over CAT, no extra hardware)', 'wkp.civReady': 'Icom CI-V ready', 'wkp.civOffline': 'Icom not connected (Settings → CAT)',
+  'wkp.sourceHint': 'CW output: WK = WinKeyer hardware · CI-V = the Icom rig’s own keyer (over CAT, no extra hardware)', 'wkp.civReady': 'Icom CI-V ready', 'wkp.civOffline': 'Icom not connected (Settings → CAT)', 'wkp.cwxReady': 'Flex CWX ready', 'wkp.cwxOffline': 'Flex not connected (Settings → CAT)',
   'wkp.cwSpeed': 'CW speed (WPM)', 'wkp.faster': 'Faster', 'wkp.slower': 'Slower', 'wkp.cwText': 'CW text', 'wkp.sendOnTypeHint': 'Key each character live as you type (backspace removes un-sent chars)', 'wkp.sendOnType': 'send on type', 'wkp.phLive': 'Type — sent live…', 'wkp.phEnter': 'Type and press Enter to send…', 'wkp.clear': 'Clear', 'wkp.send': 'Send', 'wkp.abort': 'Abort (clear keyer buffer)', 'wkp.stop': 'Stop',
   'wkp.breakIn': 'Break-in', 'wkp.breakInHint': "The rig's CW keyer only transmits when break-in is SEMI or FULL. OFF keys the sidetone but stays in receive.", 'wkp.bkOff': 'OFF', 'wkp.bkOffWarn': "won't transmit — set SEMI or FULL",
   'wkp.autoCallHint': 'Click a CQ macro (one whose text contains CQ) to resend it on a loop — message, gap, repeat — until you send another macro (e.g. a report), press Stop, or hit ESC. Non-CQ macros send once.', 'wkp.autoCall': 'Auto-call', 'wkp.gap': 'gap', 'wkp.gapHint': 'Seconds to wait after the message before resending', 'wkp.loopHint': 'click a CQ macro to loop it', 'wkp.macroN': 'Macro {n}',
@@ -572,7 +572,7 @@ const fr: Dict = {
   'ctp.stopContest': 'Arrêter le contest', 'ctp.startContest': 'Démarrer le contest', 'ctp.activeHint': 'Le formulaire de saisie affiche Env/Reç et un badge DUPE ; les QSO sont marqués avec ce contest.', 'ctp.inactiveHint': 'Choisis un contest, règle la fenêtre, puis Démarrer.', 'ctp.scoreboard': 'Tableau des scores', 'ctp.estimate': 'estimation', 'ctp.qsos': 'QSO', 'ctp.mult': 'Mult', 'ctp.scoreEst': 'Score (est.)', 'ctp.last60': 'Dernières 60 min', 'ctp.band': 'Bande',
   'adx.introPart1': 'Tous les champs ADIF 3.1.7 non affichés dans les autres onglets. Choisis un champ à ajouter, ou saisis un tag personnalisé/constructeur (ex. ', 'adx.introPart2': '). Stocké sans perte et exporté en mode ADIF ', 'adx.fullMode': 'complet', 'adx.introPart3': '.', 'adx.addFieldPh': 'Ajouter un champ ADIF…', 'adx.showDeprecated': 'Afficher les obsolètes', 'adx.noExtra': 'Aucun champ ADIF supplémentaire. Utilise le sélecteur ci-dessus pour en ajouter un.', 'adx.deprecated': 'obsolète', 'adx.intl': 'intl', 'adx.nonStandard': 'non standard', 'adx.removeField': 'Supprimer le champ',
   'wkp.sending': 'Émission…', 'wkp.connectedV': 'Connecté (v{version})', 'wkp.disconnected': 'Déconnecté', 'wkp.comPort': 'Port COM', 'wkp.noPorts': 'Aucun port', 'wkp.refreshPorts': 'Rafraîchir les ports', 'wkp.connect': 'Connecter', 'wkp.disconnect': 'Déconnecter', 'wkp.hide': 'Masquer / désactiver le WinKeyer',
-  'wkp.sourceHint': 'Sortie CW : WK = WinKeyer matériel · CI-V = le keyer interne de l’Icom (via CAT, sans matériel en plus)', 'wkp.civReady': 'Icom CI-V prêt', 'wkp.civOffline': 'Icom non connecté (Réglages → CAT)',
+  'wkp.sourceHint': 'Sortie CW : WK = WinKeyer matériel · CI-V = le keyer interne de l’Icom (via CAT, sans matériel en plus)', 'wkp.civReady': 'Icom CI-V prêt', 'wkp.civOffline': 'Icom non connecté (Réglages → CAT)', 'wkp.cwxReady': 'Flex CWX prêt', 'wkp.cwxOffline': 'Flex non connecté (Réglages → CAT)',
   'wkp.cwSpeed': 'Vitesse CW (WPM)', 'wkp.faster': 'Plus rapide', 'wkp.slower': 'Plus lent', 'wkp.cwText': 'Texte CW', 'wkp.sendOnTypeHint': 'Manipule chaque caractère en direct à la frappe (retour arrière supprime les caractères non émis)', 'wkp.sendOnType': 'émission à la frappe', 'wkp.phLive': 'Tape — émis en direct…', 'wkp.phEnter': 'Tape et appuie sur Entrée pour émettre…', 'wkp.clear': 'Effacer', 'wkp.send': 'Émettre', 'wkp.abort': 'Interrompre (vider le tampon du manipulateur)', 'wkp.stop': 'Stop',
   'wkp.breakIn': 'Break-in', 'wkp.breakInHint': "Le manipulateur interne de la radio n'émet que si le break-in est SEMI ou FULL. OFF génère la tonalité mais reste en réception.", 'wkp.bkOff': 'OFF', 'wkp.bkOffWarn': "n'émettra pas — mettre SEMI ou FULL",
   'wkp.autoCallHint': "Clique une macro CQ (dont le texte contient CQ) pour la réémettre en boucle — message, pause, répétition — jusqu'à envoyer une autre macro (ex. un report), appuyer sur Stop ou ESC. Les macros non-CQ ne sont émises qu'une fois.", 'wkp.autoCall': 'Appel auto', 'wkp.gap': 'pause', 'wkp.gapHint': 'Secondes à attendre après le message avant de réémettre', 'wkp.loopHint': 'clique une macro CQ pour la boucler', 'wkp.macroN': 'Macro {n}',

frontend/wailsjs/go/main/App.d.ts

@@ -194,6 +194,8 @@ export function FlexApplyBandAntenna(arg1:string):Promise<void>;
 
 export function FlexMox(arg1:boolean):Promise<void>;
 
+export function FlexSendCW(arg1:string):Promise<void>;
+
 export function FlexSetAGCMode(arg1:string):Promise<void>;
 
 export function FlexSetAGCThreshold(arg1:number):Promise<void>;
@@ -224,6 +226,8 @@ export function FlexSetCWSpeed(arg1:number):Promise<void>;
 
 export function FlexSetFilter(arg1:number,arg2:number):Promise<void>;
 
+export function FlexSetKeySpeed(arg1:number):Promise<void>;
+
 export function FlexSetMic(arg1:number):Promise<void>;
 
 export function FlexSetMicProfile(arg1:string):Promise<void>;
@@ -280,6 +284,8 @@ export function FlexSetXIT(arg1:boolean):Promise<void>;
 
 export function FlexSetXITFreq(arg1:number):Promise<void>;
 
+export function FlexStopCW():Promise<void>;
+
 export function FlexTune(arg1:boolean):Promise<void>;
 
 export function GetADIFMonitor():Promise<main.ADIFMonitorConfig>;

frontend/wailsjs/go/main/App.js

@@ -346,6 +346,10 @@ export function FlexMox(arg1) {
   return window['go']['main']['App']['FlexMox'](arg1);
 }
 
+export function FlexSendCW(arg1) {
+  return window['go']['main']['App']['FlexSendCW'](arg1);
+}
+
 export function FlexSetAGCMode(arg1) {
   return window['go']['main']['App']['FlexSetAGCMode'](arg1);
 }
@@ -406,6 +410,10 @@ export function FlexSetFilter(arg1, arg2) {
   return window['go']['main']['App']['FlexSetFilter'](arg1, arg2);
 }
 
+export function FlexSetKeySpeed(arg1) {
+  return window['go']['main']['App']['FlexSetKeySpeed'](arg1);
+}
+
 export function FlexSetMic(arg1) {
   return window['go']['main']['App']['FlexSetMic'](arg1);
 }
@@ -518,6 +526,10 @@ export function FlexSetXITFreq(arg1) {
   return window['go']['main']['App']['FlexSetXITFreq'](arg1);
 }
 
+export function FlexStopCW() {
+  return window['go']['main']['App']['FlexStopCW']();
+}
+
 export function FlexTune(arg1) {
   return window['go']['main']['App']['FlexTune'](arg1);
 }

internal/cat/cat.go

@@ -394,6 +394,11 @@ type FlexController interface {
 	SetCWSpeed(int) error
 	SetCWPitch(int) error
 	SetCWBreakInDelay(int) error
+	// CWX keyer — buffered CW keying via SmartSDR's CWX subsystem, so a Flex needs
+	// no WinKeyer / SmartCAT. SendCW queues text (the radio buffers and keys it);
+	// StopCW clears the buffer, aborting the send.
+	SendCW(string) error
+	StopCW() error
 	SetCWSidetone(bool) error
 	SetSidetoneLevel(int) error
 	SetCWFilter(int) error

internal/cat/flex.go

@@ -1581,6 +1581,26 @@ func (f *Flex) SetCWBreakInDelay(ms int) error {
 	return nil
 }
 
+// SendCW queues text on the radio's CWX keyer. SmartSDR buffers and keys it, so
+// no WinKeyer / SmartCAT is needed — and because the radio owns the buffer,
+// characters fed while it's already sending append and key in order (the basis
+// for type-ahead). Quotes/backslashes are escaped for the "cwx send \"…\"" form.
+func (f *Flex) SendCW(text string) error {
+	text = strings.TrimRight(text, "\r\n")
+	if strings.TrimSpace(text) == "" {
+		return nil
+	}
+	esc := strings.NewReplacer(`\`, `\\`, `"`, `\"`).Replace(text)
+	f.send(`cwx send "` + esc + `"`)
+	return nil
+}
+
+// StopCW clears the CWX buffer, aborting whatever is currently being keyed.
+func (f *Flex) StopCW() error {
+	f.send("cwx clear")
+	return nil
+}
+
 func (f *Flex) SetCWSidetone(on bool) error {
 	f.mu.Lock()
 	f.tx.cwSidetone = on