feat: Adding XIT RIT in the Flex panel

app.go

@@ -9684,6 +9684,36 @@ func (a *App) FlexApplyBandAntenna(band string) error {
 	})
 }
 
+// RIT/XIT on the active slice. The offset is kept by the radio when the switch is
+// off, so turning it back on restores it — the UI must not zero it on toggle.
+func (a *App) FlexSetRIT(on bool) error {
+	if a.cat == nil {
+		return fmt.Errorf("cat not initialized")
+	}
+	return a.cat.FlexDo(func(fc cat.FlexController) error { return fc.SetRIT(on) })
+}
+
+func (a *App) FlexSetRITFreq(hz int) error {
+	if a.cat == nil {
+		return fmt.Errorf("cat not initialized")
+	}
+	return a.cat.FlexDo(func(fc cat.FlexController) error { return fc.SetRITFreq(hz) })
+}
+
+func (a *App) FlexSetXIT(on bool) error {
+	if a.cat == nil {
+		return fmt.Errorf("cat not initialized")
+	}
+	return a.cat.FlexDo(func(fc cat.FlexController) error { return fc.SetXIT(on) })
+}
+
+func (a *App) FlexSetXITFreq(hz int) error {
+	if a.cat == nil {
+		return fmt.Errorf("cat not initialized")
+	}
+	return a.cat.FlexDo(func(fc cat.FlexController) error { return fc.SetXITFreq(hz) })
+}
+
 func (a *App) FlexSetNB(on bool) error {
 	if a.cat == nil {
 		return fmt.Errorf("cat not initialized")

frontend/src/components/FlexPanel.tsx

@@ -6,6 +6,7 @@ import {
   FlexMox, FlexAmpOperate,
   GetPGXLStatus, PGXLSetFanMode,
   FlexSetAGCMode, FlexSetAGCThreshold, FlexSetAudioLevel, FlexSetMute, FlexSetRXAntenna, FlexSetTXAntenna, FlexSetSplit, FlexSetActiveSlice, FlexSetTXSlice,
+  FlexSetRIT, FlexSetRITFreq, FlexSetXIT, FlexSetXITFreq,
   FlexSetNB, FlexSetNBLevel, FlexSetNR, FlexSetNRLevel, FlexSetANF, FlexSetANFLevel,
   FlexSetWNB, FlexSetWNBLevel, FlexSetTXFilter, FlexSetMicProfile,
   FlexSetAPF, FlexSetAPFLevel, FlexSetCWSpeed, FlexSetCWPitch, FlexSetCWBreakInDelay,
@@ -25,6 +26,7 @@ type FlexState = {
   rx_avail: boolean; agc_mode?: string; agc_threshold: number; audio_level: number; mute: boolean;
   rx_ant?: string; tx_ant?: string; ant_list?: string[]; tx_ant_list?: string[];
   split: boolean; rx_freq_hz?: number; tx_freq_hz?: number;
+  rit: boolean; rit_freq: number; xit: boolean; xit_freq: number;
   nb: boolean; nb_level: number; nr: boolean; nr_level: number; anf: boolean; anf_level: number;
   wnb: boolean; wnb_level: number;
   tx_filter_low: number; tx_filter_high: number; mic_profile?: string; mic_profiles?: string[];
@@ -44,6 +46,7 @@ const ZERO: FlexState = {
   vox_enable: false, vox_level: 0, vox_delay: 0, proc_enable: false, proc_level: 0,
   mon: false, mon_level: 0, mic_level: 0, atu_memories: false,
   rx_avail: false, agc_threshold: 0, audio_level: 0, mute: false, split: false,
+  rit: false, rit_freq: 0, xit: false, xit_freq: 0,
   nb: false, nb_level: 0, nr: false, nr_level: 0, anf: false, anf_level: 0,
   wnb: false, wnb_level: 0, tx_filter_low: 0, tx_filter_high: 0,
   cw_speed: 25, cw_pitch: 600, cw_break_in_delay: 30, cw_sidetone: true, cw_mon_level: 0,
@@ -143,6 +146,67 @@ function LevelRow({ label, on, onToggle, value, onLevel, disabled, accent, slide
   );
 }
 
+// OffsetRow — RIT / XIT: a switch plus one signed offset field you scrub with the
+// wheel (or ± , or the arrow keys once focused; hold Ctrl/Shift for 100 Hz steps).
+// Deliberately the same control as the Icom panel's ShiftRow, so the two rigs are
+// driven identically.
+//
+// The offset is NOT cleared when the switch goes off: SmartSDR keeps it, so
+// flipping RIT back on returns you exactly where you were, like the radio's own
+// knob. Zeroing it is a separate, deliberate act — that is what the 0 button is for.
+const OFFSET_MAX = 99999; // SmartSDR's limit
+function OffsetRow({ label, on, onToggle, hz, onHz, disabled, title }: {
+  label: string; on: boolean; onToggle: () => void; hz: number; onHz: (v: number) => void;
+  disabled?: boolean; title?: string;
+}) {
+  const ref = useRef<HTMLDivElement>(null);
+  const step = useRef((_d: number) => {});
+  step.current = (d: number) => onHz(Math.max(-OFFSET_MAX, Math.min(OFFSET_MAX, (hz || 0) + d)));
+
+  // React's onWheel is passive, so preventDefault() there is ignored and the panel
+  // scrolls under the cursor instead of the value changing. Bind it natively.
+  useEffect(() => {
+    const el = ref.current;
+    if (!el) return;
+    const onWheel = (e: WheelEvent) => {
+      e.preventDefault();
+      const mag = e.ctrlKey || e.shiftKey ? 100 : 10;
+      step.current(e.deltaY < 0 ? mag : -mag);
+    };
+    el.addEventListener('wheel', onWheel, { passive: false });
+    return () => el.removeEventListener('wheel', onWheel);
+  }, []);
+
+  const onKey = (e: React.KeyboardEvent) => {
+    const up = e.key === 'ArrowUp' || e.key === 'ArrowRight';
+    const dn = e.key === 'ArrowDown' || e.key === 'ArrowLeft';
+    if (!up && !dn) return;
+    e.preventDefault();
+    const mag = e.ctrlKey || e.shiftKey ? 100 : 10;
+    step.current(up ? mag : -mag);
+  };
+
+  return (
+    <div className="flex items-center gap-2" title={title}>
+      <Chip on={on} onClick={onToggle} label={label} disabled={disabled} accent="cyan" />
+      <div ref={ref} tabIndex={disabled || !on ? -1 : 0} onKeyDown={onKey}
+        className={cn('flex-1 flex items-center justify-between rounded-md border px-1 py-0.5 select-none',
+          'focus:outline-none focus:ring-2 focus:ring-info/50',
+          on && !disabled ? 'border-border bg-muted/40 cursor-ns-resize' : 'border-border/60 bg-muted/20 opacity-60')}>
+        <button type="button" disabled={disabled || !on} onClick={() => step.current(-10)}
+          className="px-2 text-sm font-bold text-muted-foreground hover:text-foreground disabled:hover:text-muted-foreground">−</button>
+        <span className={cn('text-sm font-mono font-bold tabular-nums', on && hz ? 'text-info' : 'text-muted-foreground')}>
+          {hz > 0 ? '+' : hz < 0 ? '−' : ''}{Math.abs(hz || 0)} Hz
+        </span>
+        <button type="button" disabled={disabled || !on} onClick={() => step.current(10)}
+          className="px-2 text-sm font-bold text-muted-foreground hover:text-foreground disabled:hover:text-muted-foreground">+</button>
+      </div>
+      <button type="button" disabled={disabled || !hz} onClick={() => onHz(0)}
+        className="w-8 shrink-0 py-1 rounded-md text-[11px] font-bold border border-border bg-card text-muted-foreground hover:bg-muted disabled:opacity-30">0</button>
+    </div>
+  );
+}
+
 // MeterBar — a segmented "LED" instrument bar (radio look) scaled by lo/hi.
 // `display` overrides the numeric readout; `segColor` colours segments by their
 // 0..1 position (zones); the top ~18% light red by default (overload/peak).
@@ -454,6 +518,7 @@ export function FlexPanel({ onCWSpeed, onReportRST }: { onCWSpeed?: (wpm: number
               )}
             </div>
 
+
             {!isCW ? (
             <div className="border-t border-border/60 pt-3 space-y-3">
               <div className="flex items-center gap-2">
@@ -560,6 +625,18 @@ export function FlexPanel({ onCWSpeed, onReportRST }: { onCWSpeed?: (wpm: number
                 </div>
               </div>
             )}
+            {/* RIT / XIT — on the RECEIVE side: RIT is what you reach for while
+                listening (chasing a station that drifts off your transmit frequency),
+                so it belongs with the other things you touch mid-QSO. Both act on the
+                ACTIVE slice and follow slice focus like every control here. */}
+            <div className="space-y-1.5 pb-3 border-b border-border/60">
+              <OffsetRow label="RIT" on={st.rit} disabled={rxOff} hz={st.rit_freq} title={t('flxp.ritHint')}
+                onToggle={() => change('rit', !st.rit, () => FlexSetRIT(!st.rit))}
+                onHz={(v) => change('rit_freq', v, () => FlexSetRITFreq(v))} />
+              <OffsetRow label="XIT" on={st.xit} disabled={rxOff} hz={st.xit_freq} title={t('flxp.xitHint')}
+                onToggle={() => change('xit', !st.xit, () => FlexSetXIT(!st.xit))}
+                onHz={(v) => change('xit_freq', v, () => FlexSetXITFreq(v))} />
+            </div>
             <div className="flex items-center gap-2">
               <span className="w-14 shrink-0 text-[11px] font-bold text-muted-foreground">AGC</span>
               <Segmented value={(st.agc_mode || 'med').toLowerCase()} options={AGC} disabled={rxOff}

frontend/src/lib/i18n.tsx

@@ -231,6 +231,7 @@ const en: Dict = {
   '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}',
   'dvkp.voiceKeyer': 'Voice keyer', 'dvkp.stop': 'Stop', 'dvkp.disable': 'Disable voice keyer', 'dvkp.noMsgPre': 'No messages recorded yet. Open', 'dvkp.settingsPath': 'Settings → Audio devices & voice keyer', 'dvkp.noMsgPost': 'to record F1–F6.', 'dvkp.transmit': 'Transmit F{slot}{label} ({dur}s)', 'dvkp.empty': 'F{slot} — empty', 'dvkp.message': 'message',
   'agp.portDeselect': 'Port {letter} — click to deselect', 'agp.portSelect': 'Select on port {letter}', 'agp.online': 'online', 'agp.offline': 'offline', 'agp.close': 'Close', 'agp.connecting': 'Connecting…', 'agp.noAntennas': 'No antennas configured.', 'agp.filterOnHint': 'Showing antennas for {band} only — click to show all bands', 'agp.filterOffHint': 'Showing all antennas — click to show only the current band',
+  'flxp.ritHint': 'RIT — shifts your RECEIVE frequency only. Wheel, ± or arrow keys to adjust (Ctrl = 100 Hz). The offset is kept when you switch it off.', 'flxp.xitHint': 'XIT — shifts your TRANSMIT frequency only. Wheel, ± or arrow keys to adjust (Ctrl = 100 Hz). The offset is kept when you switch it off.',
   'flxp.smartsdrRemote': 'SmartSDR remote control', 'flxp.offline': 'OFFLINE', 'flxp.waiting': 'Waiting for the FlexRadio… (set CAT to FlexRadio and connect)', 'flxp.transmit': 'Transmit', 'flxp.rfPower': 'RF Power', 'flxp.tunePwr': 'Tune Pwr', 'flxp.splitHint': 'Split: RX/TX on separate slices. ON creates a TX slice +1 kHz (CW) / +5 kHz (SSB) up, like SmartSDR.', 'flxp.sliceHint': 'Click to make this the active slice — frequency, mode, DSP and spot-clicks all follow it.', 'flxp.txSlice': 'This slice transmits', 'flxp.setTxSlice': 'Move TX to this slice (transmit here)', 'flxp.voxDly': 'VOX Dly', 'flxp.speed': 'Speed', 'flxp.pitch': 'Pitch', 'flxp.delay': 'Delay',
   'flxp.receiveActive': 'Receive (active slice)', 'flxp.muted': 'Muted — click to unmute', 'flxp.mute': 'Mute RX audio', 'flxp.filter': 'Filter', 'flxp.amplifier': 'Amplifier', 'flxp.ampInLine': 'Amplifier is in line (transmitting through PA).', 'flxp.ampBypassed': 'Amplifier bypassed (standby).', 'flxp.pgConnected': 'PowerGenius connected', 'flxp.pgOffline': 'PowerGenius offline', 'flxp.fan': 'Fan', 'flxp.fanStandard': 'Standard', 'flxp.fanContest': 'Contest', 'flxp.fanBroadcast': 'Broadcast', 'flxp.fault': 'FAULT', 'flxp.meters': 'Meters', 'flxp.voltage': 'VOLTAGE', 'flxp.paTemp': 'PA TEMP', 'flxp.txFilter': 'TX filter', 'flxp.micProfile': 'Mic profile', 'flxp.noMeters': "No meters yet — waiting for the radio's UDP stream…", 'flxp.amplifierHdr': 'AMPLIFIER',
   'icmp.spectrum': 'Spectrum', 'icmp.scopeFixed': 'Fixed — double-click / wheel to tune', 'icmp.scopeCenter': 'Center — follows VFO', 'icmp.scopeOff': 'Scope off', 'icmp.scopePanDown': 'Shift scope −50 kHz', 'icmp.scopePanUp': 'Shift scope +50 kHz', 'icmp.scopeCenterVfo': 'Center scope on the current frequency (±50 kHz)', 'icmp.notConnected': "Icom not connected. Enable the Icom CI-V backend in Settings → CAT and connect the radio's USB port.", 'icmp.refresh': 'Refresh', 'icmp.meters': 'Meters', 'icmp.transmit': 'Transmit', 'icmp.power': 'Power', 'icmp.mic': 'Mic', 'icmp.receive': 'Receive', 'icmp.preamp': 'Preamp', 'icmp.filter': 'Filter', 'icmp.noiseNotch': 'Noise / Notch', 'icmp.autoNotch': 'Auto notch filter', 'icmp.apf': 'Audio peak filter (CW)', 'icmp.clarifiers': 'RIT / ΔTX', 'icmp.ritHint': 'Wheel or ± to shift · Ctrl+←/→ shifts RIT when active', 'icmp.bandsAntenna': 'Bands & Antenna', 'icmp.antenna': 'Antenna', 'icmp.passband': 'Passband / Notch', 'icmp.pbtCenter': 'Center PBT', 'icmp.manualNotch': 'Manual notch — MN on, then set position', 'icmp.squelch': 'Squelch', 'icmp.powerOnHint': 'Power the radio ON (boots ~15 s)', 'icmp.powerOffHint': 'Power the radio OFF', 'icmp.powerOffConfirm': 'Switch the radio OFF?',
@@ -478,6 +479,7 @@ const fr: Dict = {
   '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}',
   'dvkp.voiceKeyer': 'Manipulateur vocal', 'dvkp.stop': 'Stop', 'dvkp.disable': 'Désactiver le manipulateur vocal', 'dvkp.noMsgPre': 'Aucun message enregistré. Ouvre', 'dvkp.settingsPath': 'Réglages → Périphériques audio & manipulateur vocal', 'dvkp.noMsgPost': 'pour enregistrer F1–F6.', 'dvkp.transmit': 'Émettre F{slot}{label} ({dur}s)', 'dvkp.empty': 'F{slot} — vide', 'dvkp.message': 'message',
   'agp.portDeselect': 'Port {letter} — clic pour désélectionner', 'agp.portSelect': 'Sélectionner sur le port {letter}', 'agp.online': 'en ligne', 'agp.offline': 'hors ligne', 'agp.close': 'Fermer', 'agp.connecting': 'Connexion…', 'agp.noAntennas': 'Aucune antenne configurée.', 'agp.filterOnHint': 'Antennes du {band} uniquement — clic pour afficher toutes les bandes', 'agp.filterOffHint': 'Toutes les antennes affichées — clic pour n’afficher que la bande courante',
+  'flxp.ritHint': "RIT — décale uniquement ta fréquence de RÉCEPTION. Molette, ± ou flèches pour ajuster (Ctrl = 100 Hz). Le décalage est conservé quand tu l'éteins.", 'flxp.xitHint': "XIT — décale uniquement ta fréquence d'ÉMISSION. Molette, ± ou flèches pour ajuster (Ctrl = 100 Hz). Le décalage est conservé quand tu l'éteins.",
   'flxp.smartsdrRemote': 'Contrôle à distance SmartSDR', 'flxp.offline': 'HORS LIGNE', 'flxp.waiting': 'En attente du FlexRadio… (règle le CAT sur FlexRadio et connecte)', 'flxp.transmit': 'Émission', 'flxp.rfPower': 'Puissance RF', 'flxp.tunePwr': 'Puiss. TUNE', 'flxp.splitHint': 'Split : RX/TX sur des slices séparées. ON crée une slice TX +1 kHz (CW) / +5 kHz (SSB) au-dessus, comme SmartSDR.', 'flxp.sliceHint': 'Cliquer pour rendre cette slice active — fréquence, mode, DSP et clics de spot la suivent tous.', 'flxp.txSlice': 'Cette slice émet', 'flxp.setTxSlice': 'Déplacer le TX sur cette slice (émettre ici)', 'flxp.voxDly': 'Délai VOX', 'flxp.speed': 'Vitesse', 'flxp.pitch': 'Tonalité', 'flxp.delay': 'Délai',
   'flxp.receiveActive': 'Réception (slice active)', 'flxp.muted': 'Coupé — clic pour rétablir', 'flxp.mute': "Couper l'audio RX", 'flxp.filter': 'Filtre', 'flxp.amplifier': 'Amplificateur', 'flxp.ampInLine': 'Amplificateur en ligne (émission via le PA).', 'flxp.ampBypassed': 'Amplificateur en bypass (standby).', 'flxp.pgConnected': 'PowerGenius connecté', 'flxp.pgOffline': 'PowerGenius hors ligne', 'flxp.fan': 'Ventilo', 'flxp.fanStandard': 'Standard', 'flxp.fanContest': 'Contest', 'flxp.fanBroadcast': 'Diffusion', 'flxp.fault': 'DÉFAUT', 'flxp.meters': 'Mesures', 'flxp.voltage': 'TENSION', 'flxp.paTemp': 'TEMP PA', 'flxp.txFilter': 'Filtre TX', 'flxp.micProfile': 'Profil micro', 'flxp.noMeters': 'Aucune mesure — en attente du flux UDP de la radio…', 'flxp.amplifierHdr': 'AMPLIFICATEUR',
   'icmp.spectrum': 'Spectre', 'icmp.scopeFixed': 'Fixe — double-clic / molette pour accorder', 'icmp.scopeCenter': 'Centré — suit le VFO', 'icmp.scopeOff': 'Scope éteint', 'icmp.scopePanDown': 'Décaler le scope −50 kHz', 'icmp.scopePanUp': 'Décaler le scope +50 kHz', 'icmp.scopeCenterVfo': 'Centrer le scope sur la fréquence actuelle (±50 kHz)', 'icmp.notConnected': 'Icom non connecté. Active le backend CI-V Icom dans Réglages → CAT et connecte le port USB de la radio.', 'icmp.refresh': 'Rafraîchir', 'icmp.meters': 'Mesures', 'icmp.transmit': 'Émission', 'icmp.power': 'Puissance', 'icmp.mic': 'Micro', 'icmp.receive': 'Réception', 'icmp.preamp': 'Préampli', 'icmp.filter': 'Filtre', 'icmp.noiseNotch': 'Bruit / Notch', 'icmp.autoNotch': 'Filtre notch auto', 'icmp.apf': 'Filtre de pic audio (CW)', 'icmp.clarifiers': 'RIT / ΔTX', 'icmp.ritHint': 'Molette ou ± pour décaler · Ctrl+←/→ décale le RIT si actif', 'icmp.bandsAntenna': 'Bandes & Antenne', 'icmp.antenna': 'Antenne', 'icmp.passband': 'Passe-bande / Notch', 'icmp.pbtCenter': 'Centrer PBT', 'icmp.manualNotch': 'Notch manuel — active MN, puis règle la position', 'icmp.squelch': 'Squelch', 'icmp.powerOnHint': 'Allumer la radio (démarre en ~15 s)', 'icmp.powerOffHint': 'Éteindre la radio', 'icmp.powerOffConfirm': 'Éteindre la radio ?',

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

@@ -240,6 +240,10 @@ export function FlexSetProcessor(arg1:boolean):Promise<void>;
 
 export function FlexSetProcessorLevel(arg1:number):Promise<void>;
 
+export function FlexSetRIT(arg1:boolean):Promise<void>;
+
+export function FlexSetRITFreq(arg1:number):Promise<void>;
+
 export function FlexSetRXAntenna(arg1:string):Promise<void>;
 
 export function FlexSetSidetoneLevel(arg1:number):Promise<void>;
@@ -264,6 +268,10 @@ export function FlexSetWNB(arg1:boolean):Promise<void>;
 
 export function FlexSetWNBLevel(arg1:number):Promise<void>;
 
+export function FlexSetXIT(arg1:boolean):Promise<void>;
+
+export function FlexSetXITFreq(arg1:number):Promise<void>;
+
 export function FlexTune(arg1:boolean):Promise<void>;
 
 export function GetActiveProfile():Promise<profile.Profile>;

frontend/wailsjs/go/main/App.js

@@ -438,6 +438,14 @@ export function FlexSetProcessorLevel(arg1) {
   return window['go']['main']['App']['FlexSetProcessorLevel'](arg1);
 }
 
+export function FlexSetRIT(arg1) {
+  return window['go']['main']['App']['FlexSetRIT'](arg1);
+}
+
+export function FlexSetRITFreq(arg1) {
+  return window['go']['main']['App']['FlexSetRITFreq'](arg1);
+}
+
 export function FlexSetRXAntenna(arg1) {
   return window['go']['main']['App']['FlexSetRXAntenna'](arg1);
 }
@@ -486,6 +494,14 @@ export function FlexSetWNBLevel(arg1) {
   return window['go']['main']['App']['FlexSetWNBLevel'](arg1);
 }
 
+export function FlexSetXIT(arg1) {
+  return window['go']['main']['App']['FlexSetXIT'](arg1);
+}
+
+export function FlexSetXITFreq(arg1) {
+  return window['go']['main']['App']['FlexSetXITFreq'](arg1);
+}
+
 export function FlexTune(arg1) {
   return window['go']['main']['App']['FlexTune'](arg1);
 }

frontend/wailsjs/go/models.ts

@@ -722,6 +722,10 @@ export namespace cat {
 	    anf_level: number;
 	    wnb: boolean;
 	    wnb_level: number;
+	    rit: boolean;
+	    rit_freq: number;
+	    xit: boolean;
+	    xit_freq: number;
 	    mode?: string;
 	    cw_speed: number;
 	    cw_pitch: number;
@@ -785,6 +789,10 @@ export namespace cat {
 	        this.anf_level = source["anf_level"];
 	        this.wnb = source["wnb"];
 	        this.wnb_level = source["wnb_level"];
+	        this.rit = source["rit"];
+	        this.rit_freq = source["rit_freq"];
+	        this.xit = source["xit"];
+	        this.xit_freq = source["xit_freq"];
 	        this.mode = source["mode"];
 	        this.cw_speed = source["cw_speed"];
 	        this.cw_pitch = source["cw_pitch"];

internal/cat/cat.go

@@ -304,6 +304,13 @@ type FlexTXState struct {
 	ANFLevel     int      `json:"anf_level"`
 	WNB          bool     `json:"wnb"`
 	WNBLevel     int      `json:"wnb_level"`
+	// RIT/XIT — offsets applied to the active slice's RX / TX frequency without
+	// moving the slice. The offset survives the switch being turned off, so
+	// re-enabling restores it, exactly like the radio's own knob.
+	RIT     bool `json:"rit"`
+	RITFreq int  `json:"rit_freq"`
+	XIT     bool `json:"xit"`
+	XITFreq int  `json:"xit_freq"`
 	// CW / mode-specific controls.
 	Mode           string `json:"mode,omitempty"` // active slice mode (CW/USB/LSB/DIGU…)
 	CWSpeed        int    `json:"cw_speed"`
@@ -378,6 +385,10 @@ type FlexController interface {
 	SetAPFLevel(int) error
 	SetWNB(bool) error
 	SetWNBLevel(int) error
+	SetRIT(bool) error
+	SetRITFreq(int) error
+	SetXIT(bool) error
+	SetXITFreq(int) error
 	// CW keyer + mode-specific controls.
 	SetCWSpeed(int) error
 	SetCWPitch(int) error

internal/cat/flex.go

@@ -90,8 +90,12 @@ type flexSlice struct {
 	apfLevel     int
 	wnb          bool // wideband noise blanker
 	wnbLevel     int
-	filterLo     int      // slice filter low cut (Hz)
-	filterHi     int      // slice filter high cut (Hz)
+	rit          bool // receive incremental tuning enabled
+	ritFreq      int  // RIT offset in Hz (negative = down)
+	xit          bool // transmit incremental tuning enabled
+	xitFreq      int  // XIT offset in Hz
+	filterLo     int  // slice filter low cut (Hz)
+	filterHi     int  // slice filter high cut (Hz)
 	rxAnt        string   // selected RX antenna (e.g. ANT1, ANT2, RX_A)
 	txAnt        string   // selected TX antenna
 	antList      []string // antennas valid for this slice (RX side)
@@ -804,6 +808,14 @@ func (f *Flex) handleStatus(payload string) {
 			s.wnb = val == "1"
 		case "wnb_level":
 			s.wnbLevel = atoiDefault(val, s.wnbLevel)
+		case "rit_on":
+			s.rit = val == "1"
+		case "rit_freq":
+			s.ritFreq = atoiDefault(val, s.ritFreq)
+		case "xit_on":
+			s.xit = val == "1"
+		case "xit_freq":
+			s.xitFreq = atoiDefault(val, s.xitFreq)
 		case "filter_lo":
 			s.filterLo = atoiDefault(val, s.filterLo)
 		case "filter_hi":
@@ -1315,6 +1327,10 @@ func (f *Flex) FlexState() FlexTXState {
 		st.APFLevel = rx.apfLevel
 		st.WNB = rx.wnb
 		st.WNBLevel = rx.wnbLevel
+		st.RIT = rx.rit
+		st.RITFreq = rx.ritFreq
+		st.XIT = rx.xit
+		st.XITFreq = rx.xitFreq
 		st.FilterLo = rx.filterLo
 		st.FilterHi = rx.filterHi
 		st.RXAnt = rx.rxAnt
@@ -1383,6 +1399,14 @@ func (f *Flex) sendSlice(param string, val any) error {
 			rx.rxAnt = fmt.Sprint(val)
 		case "txant":
 			rx.txAnt = fmt.Sprint(val)
+		case "rit_on":
+			rx.rit = val == "1"
+		case "rit_freq":
+			rx.ritFreq = toInt(val)
+		case "xit_on":
+			rx.xit = val == "1"
+		case "xit_freq":
+			rx.xitFreq = toInt(val)
 		}
 	}
 	f.mu.Unlock()
@@ -1490,6 +1514,26 @@ func (f *Flex) SetNR(on bool) error     { return f.sendSlice("nr", boolFlex(on))
 func (f *Flex) SetNRLevel(l int) error  { return f.sendSlice("nr_level", clampLevel(l)) }
 func (f *Flex) SetANF(on bool) error    { return f.sendSlice("anf", boolFlex(on)) }
 func (f *Flex) SetANFLevel(l int) error { return f.sendSlice("anf_level", clampLevel(l)) }
+// RIT/XIT — an offset applied to the RX (RIT) or TX (XIT) frequency of the active
+// slice, without moving the slice itself. SmartSDR keeps the offset even while the
+// switch is off, so turning RIT back on restores the last offset — same as the
+// radio's own knob.
+func (f *Flex) SetRIT(on bool) error      { return f.sendSlice("rit_on", boolFlex(on)) }
+func (f *Flex) SetRITFreq(hz int) error   { return f.sendSlice("rit_freq", clampOffset(hz)) }
+func (f *Flex) SetXIT(on bool) error      { return f.sendSlice("xit_on", boolFlex(on)) }
+func (f *Flex) SetXITFreq(hz int) error   { return f.sendSlice("xit_freq", clampOffset(hz)) }
+
+// clampOffset keeps a RIT/XIT offset inside what SmartSDR accepts (±99 999 Hz).
+func clampOffset(hz int) int {
+	if hz > 99999 {
+		return 99999
+	}
+	if hz < -99999 {
+		return -99999
+	}
+	return hz
+}
+
 func (f *Flex) SetAPF(on bool) error    { return f.sendSlice("apf", boolFlex(on)) }
 func (f *Flex) SetAPFLevel(l int) error { return f.sendSlice("apf_level", clampLevel(l)) }
 func (f *Flex) SetWNB(on bool) error    { return f.sendSlice("wnb", boolFlex(on)) }