diff --git a/app/diario-bordo.html b/app/diario-bordo.html
index 1da2e13..cf56ff6 100644
--- a/app/diario-bordo.html
+++ b/app/diario-bordo.html
@@ -528,6 +528,15 @@ header{
 .fleet-units-toggle button.active{background:var(--brass);color:var(--bg-paper)}
 .fleet-units-toggle button:hover:not(.active){background:var(--bg-aged)}
 
+/* === Sync Indicator === */
+.sync-indicator{
+  display:inline-block;font-size:10px;
+  margin-left:6px;cursor:help;
+  vertical-align:1px;
+}
+.sync-indicator[data-status="syncing"]{animation:syncPulse 1.2s infinite}
+@keyframes syncPulse{0%,100%{opacity:1}50%{opacity:.4}}
+
 /* === Boat Photo === */
 .boat-photo-row{display:flex;gap:14px;align-items:flex-start}
 .boat-photo-preview{
@@ -1368,7 +1377,7 @@ header{
 </svg>
 <div class="boat-header-avatar" id="boat-header-avatar" onclick="openFleetManager()" style="cursor:pointer" title="Gerenciar frota">⛵</div>
 <div class="boat-info">
-<div class="boat-tagline">Diário de Bordo · Logbook</div>
+<div class="boat-tagline">Diário de Bordo · Logbook <span class="sync-indicator" id="sync-indicator" data-status="disabled" title="Sync na nuvem desligado">⚫</span></div>
 <button type="button" class="boat-name boat-selector" id="boat-selector" onclick="openFleetManager()" title="Gerenciar frota">
   <span id="boat-name-display">Shivao</span>
   <span class="boat-chevron" aria-hidden="true">▾</span>
@@ -2216,7 +2225,11 @@ function loadState(){try{const raw=localStorage.getItem(STORAGE_KEY);if(raw){con
     saveState();
   }
 }
-function saveState(){try{localStorage.setItem(STORAGE_KEY,JSON.stringify(state))}catch(e){toast('Erro ao salvar')}}
+function saveState(){
+  try{localStorage.setItem(STORAGE_KEY,JSON.stringify(state))}catch(e){toast('Erro ao salvar')}
+  // Auto-push pra nuvem (debounced) — só se cloud configurada
+  if(typeof scheduleCloudPush==='function')scheduleCloudPush();
+}
 
 function uid(){return Date.now().toString(36)+Math.random().toString(36).slice(2,7)}
 const MESES=['JAN','FEV','MAR','ABR','MAI','JUN','JUL','AGO','SET','OUT','NOV','DEZ'];
@@ -2981,10 +2994,22 @@ async function updateStorageInfo(){
   initBattery();
   initServiceWorker();
   initSensorWidget();
+  // Realtime sync: conecta WebSocket se cloud configurada
+  setSyncStatus(cloudConfigured()?'syncing':'disabled');
+  if(cloudConfigured())rtConnect();
   // tenta auto-fetch do tempo após pequeno delay
   setTimeout(maybeAutoFetchWeather,3000);
 })();
-document.addEventListener('visibilitychange',async()=>{if(document.visibilityState==='visible'){if(tracking.active&&!tracking.wakeLock)await requestWakeLock();if(anchorWatch.active&&!anchorWatch.wakeLock)await requestAnchorWakeLock()}});
+document.addEventListener('visibilitychange',async()=>{
+  if(document.visibilityState==='visible'){
+    if(tracking.active&&!tracking.wakeLock)await requestWakeLock();
+    if(anchorWatch.active&&!anchorWatch.wakeLock)await requestAnchorWakeLock();
+    // Reconecta WS ao voltar ao foreground
+    if(cloudConfigured()&&(!_wsConn||_wsConn.readyState!==WebSocket.OPEN))rtConnect();
+  }
+});
+window.addEventListener('online',()=>{if(cloudConfigured())rtConnect()});
+window.addEventListener('offline',()=>setSyncStatus('offline'));
 
 // ============ ANCHOR WATCH ============
 const anchorWatch={active:false,watchId:null,startedAt:null,anchorPos:null,swingPos:null,radius:50,currentDist:0,maxDist:0,wakeLock:null,alarmFired:false,alarmCount:0,autoRecenter:false,recentPositions:[]};
@@ -3629,6 +3654,185 @@ async function cloudFetch(path,opts={}){
   return r;
 }
 
+// ============ REALTIME SYNC (WebSocket + auto push/pull) ============
+// Conecta ao /ws do servidor, escuta notificações de mudança de outros devices
+// e dispara pull/push automáticos. Reconnect com backoff exponencial.
+
+const SYNC_DEBOUNCE_MS=2500;
+const SYNC_PULL_DEBOUNCE_MS=300;
+let _wsConn=null;
+let _wsReconnectTimer=null;
+let _wsReconnectAttempt=0;
+let _wsHeartbeatTimer=null;
+let _wsPushTimer=null;
+let _wsPullTimer=null;
+let _wsLastPushAt=0;
+let _wsSyncInFlight=false;
+
+function getDeviceId(){
+  let id=localStorage.getItem('shivao_device_id');
+  if(!id){id='dev-'+Math.random().toString(36).slice(2,12);localStorage.setItem('shivao_device_id',id)}
+  return id;
+}
+
+function setSyncStatus(status,detail){
+  // status: 'online' | 'syncing' | 'offline' | 'disabled' | 'error'
+  const el=document.getElementById('sync-indicator');
+  if(!el)return;
+  el.dataset.status=status;
+  const labels={online:'🟢',syncing:'🟡',offline:'🔴',disabled:'⚫',error:'⚠️'};
+  const titles={
+    online:'Sincronizado em tempo real',
+    syncing:'Sincronizando...',
+    offline:'Sem conexão (mudanças salvas localmente)',
+    disabled:'Sync na nuvem desligado — toque em Arquivo › Nuvem',
+    error:'Erro de sincronização'
+  };
+  el.textContent=labels[status]||'';
+  el.title=(titles[status]||'')+(detail?' — '+detail:'');
+}
+
+function rtConnect(){
+  if(!cloudConfigured()){setSyncStatus('disabled');return}
+  if(_wsConn&&(_wsConn.readyState===WebSocket.OPEN||_wsConn.readyState===WebSocket.CONNECTING))return;
+  try{
+    const baseUrl=state.cloud.url.replace(/\/$/,'').replace(/^http/,'ws');
+    const tok=(state.auth&&state.auth.accessToken)?state.auth.accessToken:state.cloud.token;
+    const url=`${baseUrl}/ws?token=${encodeURIComponent(tok)}&device=${encodeURIComponent(getDeviceId())}`;
+    _wsConn=new WebSocket(url);
+    setSyncStatus('syncing','conectando...');
+  }catch(e){
+    console.warn('[rt] connect failed',e);
+    scheduleRtReconnect();
+    return;
+  }
+
+  _wsConn.onopen=()=>{
+    _wsReconnectAttempt=0;
+    setSyncStatus('online');
+    // Pull inicial: garante state fresco quando conecta
+    schedulePull();
+    // Heartbeat
+    if(_wsHeartbeatTimer)clearInterval(_wsHeartbeatTimer);
+    _wsHeartbeatTimer=setInterval(()=>{
+      if(_wsConn&&_wsConn.readyState===WebSocket.OPEN){
+        try{_wsConn.send(JSON.stringify({type:'ping'}))}catch(e){}
+      }
+    },25000);
+  };
+
+  _wsConn.onmessage=(ev)=>{
+    let msg;try{msg=JSON.parse(ev.data)}catch(e){return}
+    if(msg.type==='hello'){
+      console.log('[rt] hello',msg);
+    }else if(msg.type==='state:changed'){
+      // Outro device alterou o state: pull
+      if(msg.originDeviceId===getDeviceId())return; // echo do nosso próprio push
+      schedulePull();
+    }else if(msg.type==='presence'){
+      const el=document.getElementById('sync-indicator');
+      if(el&&msg.count>1)el.title=`Sincronizado em tempo real · ${msg.count} dispositivos online`;
+    }else if(msg.type==='error'){
+      console.warn('[rt] server error',msg);
+      setSyncStatus('error',msg.code);
+    }
+  };
+
+  _wsConn.onerror=(e)=>{console.warn('[rt] ws error',e)};
+  _wsConn.onclose=(ev)=>{
+    if(_wsHeartbeatTimer){clearInterval(_wsHeartbeatTimer);_wsHeartbeatTimer=null}
+    _wsConn=null;
+    if(!cloudConfigured()){setSyncStatus('disabled');return}
+    setSyncStatus('offline');
+    if(ev.code!==1008)scheduleRtReconnect(); // 1008 = auth fail, não retentar
+  };
+}
+
+function scheduleRtReconnect(){
+  if(_wsReconnectTimer)clearTimeout(_wsReconnectTimer);
+  const delays=[1000,2000,5000,15000,30000,60000];
+  const delay=delays[Math.min(_wsReconnectAttempt,delays.length-1)];
+  _wsReconnectAttempt++;
+  _wsReconnectTimer=setTimeout(()=>rtConnect(),delay);
+}
+
+function rtDisconnect(){
+  if(_wsReconnectTimer){clearTimeout(_wsReconnectTimer);_wsReconnectTimer=null}
+  if(_wsHeartbeatTimer){clearInterval(_wsHeartbeatTimer);_wsHeartbeatTimer=null}
+  if(_wsConn){try{_wsConn.close(1000,'client disconnect')}catch(e){}_wsConn=null}
+  setSyncStatus('disabled');
+}
+
+// Push debounced — chamado de saveState. Só sobe quando configurado.
+function scheduleCloudPush(){
+  if(!cloudConfigured())return;
+  if(_wsPushTimer)clearTimeout(_wsPushTimer);
+  _wsPushTimer=setTimeout(()=>autoPushNow().catch(()=>{}),SYNC_DEBOUNCE_MS);
+}
+
+async function autoPushNow(){
+  if(!cloudConfigured())return;
+  if(_wsSyncInFlight)return;
+  _wsSyncInFlight=true;
+  setSyncStatus('syncing','enviando...');
+  try{
+    const{cloud,...dataNoCloud}=state;
+    await cloudFetch('/api/data?device='+encodeURIComponent(getDeviceId()),{
+      method:'POST',
+      headers:{'X-Device-Id':getDeviceId()},
+      body:JSON.stringify({data:dataNoCloud}),
+    });
+    state.cloud.lastSync=Date.now();
+    _wsLastPushAt=Date.now();
+    try{localStorage.setItem(STORAGE_KEY,JSON.stringify(state))}catch(e){}
+    setSyncStatus(_wsConn&&_wsConn.readyState===WebSocket.OPEN?'online':'offline');
+    if(typeof renderCloudStatus==='function')renderCloudStatus();
+  }catch(e){
+    console.warn('[rt] push failed',e.message);
+    setSyncStatus('error',e.message);
+  }finally{
+    _wsSyncInFlight=false;
+  }
+}
+
+// Pull debounced — chamado quando WS notifica mudança remota
+function schedulePull(){
+  if(_wsPullTimer)clearTimeout(_wsPullTimer);
+  _wsPullTimer=setTimeout(()=>autoPullNow().catch(()=>{}),SYNC_PULL_DEBOUNCE_MS);
+}
+
+async function autoPullNow(){
+  if(!cloudConfigured())return;
+  if(_wsSyncInFlight)return;
+  // Não puxa se acabamos de empurrar (echo guard adicional)
+  if(Date.now()-_wsLastPushAt<1000)return;
+  _wsSyncInFlight=true;
+  setSyncStatus('syncing','baixando...');
+  try{
+    const r=await cloudFetch('/api/data');
+    const{data,updated_at}=await r.json();
+    if(!data){setSyncStatus('online');_wsSyncInFlight=false;return}
+    // Se o updated_at remoto é mais antigo que nosso último push, ignora (evita rollback)
+    if(updated_at&&_wsLastPushAt&&updated_at<_wsLastPushAt){_wsSyncInFlight=false;setSyncStatus('online');return}
+    const cloudKeep=state.cloud;
+    const authKeep=state.auth;
+    Object.assign(state,data);
+    state.cloud=cloudKeep;
+    if(authKeep)state.auth=authKeep;
+    state.cloud.lastSync=Date.now();
+    try{localStorage.setItem(STORAGE_KEY,JSON.stringify(state))}catch(e){}
+    bindHeader();
+    if(typeof renderAll==='function')await renderAll();
+    setSyncStatus('online','recebido de outro dispositivo');
+    toast('🔄 Atualizado por outro dispositivo');
+  }catch(e){
+    console.warn('[rt] pull failed',e.message);
+    setSyncStatus('error',e.message);
+  }finally{
+    _wsSyncInFlight=false;
+  }
+}
+
 // ===== Auth (multi-tenant SaaS — Login/Signup) =====
 async function authSignup(email,password,name){
   if(!cloudConfigured())throw new Error('Configure URL do servidor primeiro');
@@ -3813,8 +4017,8 @@ function bindCloudInputs(){
   if(!u||!t)return;
   u.value=state.cloud?.url||'';
   t.value=state.cloud?.token||'';
-  u.addEventListener('change',()=>{state.cloud.url=u.value.trim();saveState();renderCloudStatus()});
-  t.addEventListener('change',()=>{state.cloud.token=t.value.trim();saveState();renderCloudStatus()});
+  u.addEventListener('change',()=>{state.cloud.url=u.value.trim();saveState();renderCloudStatus();rtDisconnect();if(cloudConfigured())rtConnect()});
+  t.addEventListener('change',()=>{state.cloud.token=t.value.trim();saveState();renderCloudStatus();rtDisconnect();if(cloudConfigured())rtConnect()});
 }
 
 function renderCloudStatus(){
diff --git a/mobile/android/app/build.gradle b/mobile/android/app/build.gradle
index d22f079..48d02ea 100644
--- a/mobile/android/app/build.gradle
+++ b/mobile/android/app/build.gradle
@@ -7,8 +7,8 @@ android {
         applicationId "br.com.pontualtech.shivao"
         minSdkVersion rootProject.ext.minSdkVersion
         targetSdkVersion rootProject.ext.targetSdkVersion
-        versionCode 5
-        versionName "1.4.1"
+        versionCode 6
+        versionName "1.5.0"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         aaptOptions {
              // Files and dirs to omit from the packaged assets dir, modified to accommodate modern web apps.
diff --git a/mobile/package.json b/mobile/package.json
index 03183e9..5b29636 100644
--- a/mobile/package.json
+++ b/mobile/package.json
@@ -1,6 +1,6 @@
 {
   "name": "shivao-mobile",
-  "version": "1.4.1",
+  "version": "1.5.0",
   "description": "Shivao app nativo (Capacitor wrapper Android/iOS)",
   "main": "index.js",
   "type": "module",
diff --git a/server/package-lock.json b/server/package-lock.json
index ee2e915..0cce9fd 100644
--- a/server/package-lock.json
+++ b/server/package-lock.json
@@ -16,6 +16,7 @@
         "jsonwebtoken": "^9.0.3",
         "multer": "^1.4.5-lts.1",
         "nodemailer": "^6.9.15",
+        "ws": "^8.20.0",
         "zod": "^4.3.6"
       },
       "engines": {
@@ -1574,6 +1575,27 @@
       "integrity": "sha512-l4Sp/DRseor9wL6EvV2+TuQn63dMkPjZ/sp9XkghTEbV9KlPS1xUsZ3u7/IQO4wxtcFB4bgpQPRcR3QCvezPcQ==",
       "license": "ISC"
     },
+    "node_modules/ws": {
+      "version": "8.20.0",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-8.20.0.tgz",
+      "integrity": "sha512-sAt8BhgNbzCtgGbt2OxmpuryO63ZoDk/sqaB/znQm94T4fCEsy/yV+7CdC1kJhOU9lboAEU7R3kquuycDoibVA==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=10.0.0"
+      },
+      "peerDependencies": {
+        "bufferutil": "^4.0.1",
+        "utf-8-validate": ">=5.0.2"
+      },
+      "peerDependenciesMeta": {
+        "bufferutil": {
+          "optional": true
+        },
+        "utf-8-validate": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/xtend": {
       "version": "4.0.2",
       "resolved": "https://registry.npmjs.org/xtend/-/xtend-4.0.2.tgz",
diff --git a/server/package.json b/server/package.json
index 6d216ff..0c64497 100644
--- a/server/package.json
+++ b/server/package.json
@@ -19,6 +19,7 @@
     "jsonwebtoken": "^9.0.3",
     "multer": "^1.4.5-lts.1",
     "nodemailer": "^6.9.15",
+    "ws": "^8.20.0",
     "zod": "^4.3.6"
   },
   "license": "MIT"
diff --git a/server/public/index.html b/server/public/index.html
index 1da2e13..cf56ff6 100644
--- a/server/public/index.html
+++ b/server/public/index.html
@@ -528,6 +528,15 @@ header{
 .fleet-units-toggle button.active{background:var(--brass);color:var(--bg-paper)}
 .fleet-units-toggle button:hover:not(.active){background:var(--bg-aged)}
 
+/* === Sync Indicator === */
+.sync-indicator{
+  display:inline-block;font-size:10px;
+  margin-left:6px;cursor:help;
+  vertical-align:1px;
+}
+.sync-indicator[data-status="syncing"]{animation:syncPulse 1.2s infinite}
+@keyframes syncPulse{0%,100%{opacity:1}50%{opacity:.4}}
+
 /* === Boat Photo === */
 .boat-photo-row{display:flex;gap:14px;align-items:flex-start}
 .boat-photo-preview{
@@ -1368,7 +1377,7 @@ header{
 </svg>
 <div class="boat-header-avatar" id="boat-header-avatar" onclick="openFleetManager()" style="cursor:pointer" title="Gerenciar frota">⛵</div>
 <div class="boat-info">
-<div class="boat-tagline">Diário de Bordo · Logbook</div>
+<div class="boat-tagline">Diário de Bordo · Logbook <span class="sync-indicator" id="sync-indicator" data-status="disabled" title="Sync na nuvem desligado">⚫</span></div>
 <button type="button" class="boat-name boat-selector" id="boat-selector" onclick="openFleetManager()" title="Gerenciar frota">
   <span id="boat-name-display">Shivao</span>
   <span class="boat-chevron" aria-hidden="true">▾</span>
@@ -2216,7 +2225,11 @@ function loadState(){try{const raw=localStorage.getItem(STORAGE_KEY);if(raw){con
     saveState();
   }
 }
-function saveState(){try{localStorage.setItem(STORAGE_KEY,JSON.stringify(state))}catch(e){toast('Erro ao salvar')}}
+function saveState(){
+  try{localStorage.setItem(STORAGE_KEY,JSON.stringify(state))}catch(e){toast('Erro ao salvar')}
+  // Auto-push pra nuvem (debounced) — só se cloud configurada
+  if(typeof scheduleCloudPush==='function')scheduleCloudPush();
+}
 
 function uid(){return Date.now().toString(36)+Math.random().toString(36).slice(2,7)}
 const MESES=['JAN','FEV','MAR','ABR','MAI','JUN','JUL','AGO','SET','OUT','NOV','DEZ'];
@@ -2981,10 +2994,22 @@ async function updateStorageInfo(){
   initBattery();
   initServiceWorker();
   initSensorWidget();
+  // Realtime sync: conecta WebSocket se cloud configurada
+  setSyncStatus(cloudConfigured()?'syncing':'disabled');
+  if(cloudConfigured())rtConnect();
   // tenta auto-fetch do tempo após pequeno delay
   setTimeout(maybeAutoFetchWeather,3000);
 })();
-document.addEventListener('visibilitychange',async()=>{if(document.visibilityState==='visible'){if(tracking.active&&!tracking.wakeLock)await requestWakeLock();if(anchorWatch.active&&!anchorWatch.wakeLock)await requestAnchorWakeLock()}});
+document.addEventListener('visibilitychange',async()=>{
+  if(document.visibilityState==='visible'){
+    if(tracking.active&&!tracking.wakeLock)await requestWakeLock();
+    if(anchorWatch.active&&!anchorWatch.wakeLock)await requestAnchorWakeLock();
+    // Reconecta WS ao voltar ao foreground
+    if(cloudConfigured()&&(!_wsConn||_wsConn.readyState!==WebSocket.OPEN))rtConnect();
+  }
+});
+window.addEventListener('online',()=>{if(cloudConfigured())rtConnect()});
+window.addEventListener('offline',()=>setSyncStatus('offline'));
 
 // ============ ANCHOR WATCH ============
 const anchorWatch={active:false,watchId:null,startedAt:null,anchorPos:null,swingPos:null,radius:50,currentDist:0,maxDist:0,wakeLock:null,alarmFired:false,alarmCount:0,autoRecenter:false,recentPositions:[]};
@@ -3629,6 +3654,185 @@ async function cloudFetch(path,opts={}){
   return r;
 }
 
+// ============ REALTIME SYNC (WebSocket + auto push/pull) ============
+// Conecta ao /ws do servidor, escuta notificações de mudança de outros devices
+// e dispara pull/push automáticos. Reconnect com backoff exponencial.
+
+const SYNC_DEBOUNCE_MS=2500;
+const SYNC_PULL_DEBOUNCE_MS=300;
+let _wsConn=null;
+let _wsReconnectTimer=null;
+let _wsReconnectAttempt=0;
+let _wsHeartbeatTimer=null;
+let _wsPushTimer=null;
+let _wsPullTimer=null;
+let _wsLastPushAt=0;
+let _wsSyncInFlight=false;
+
+function getDeviceId(){
+  let id=localStorage.getItem('shivao_device_id');
+  if(!id){id='dev-'+Math.random().toString(36).slice(2,12);localStorage.setItem('shivao_device_id',id)}
+  return id;
+}
+
+function setSyncStatus(status,detail){
+  // status: 'online' | 'syncing' | 'offline' | 'disabled' | 'error'
+  const el=document.getElementById('sync-indicator');
+  if(!el)return;
+  el.dataset.status=status;
+  const labels={online:'🟢',syncing:'🟡',offline:'🔴',disabled:'⚫',error:'⚠️'};
+  const titles={
+    online:'Sincronizado em tempo real',
+    syncing:'Sincronizando...',
+    offline:'Sem conexão (mudanças salvas localmente)',
+    disabled:'Sync na nuvem desligado — toque em Arquivo › Nuvem',
+    error:'Erro de sincronização'
+  };
+  el.textContent=labels[status]||'';
+  el.title=(titles[status]||'')+(detail?' — '+detail:'');
+}
+
+function rtConnect(){
+  if(!cloudConfigured()){setSyncStatus('disabled');return}
+  if(_wsConn&&(_wsConn.readyState===WebSocket.OPEN||_wsConn.readyState===WebSocket.CONNECTING))return;
+  try{
+    const baseUrl=state.cloud.url.replace(/\/$/,'').replace(/^http/,'ws');
+    const tok=(state.auth&&state.auth.accessToken)?state.auth.accessToken:state.cloud.token;
+    const url=`${baseUrl}/ws?token=${encodeURIComponent(tok)}&device=${encodeURIComponent(getDeviceId())}`;
+    _wsConn=new WebSocket(url);
+    setSyncStatus('syncing','conectando...');
+  }catch(e){
+    console.warn('[rt] connect failed',e);
+    scheduleRtReconnect();
+    return;
+  }
+
+  _wsConn.onopen=()=>{
+    _wsReconnectAttempt=0;
+    setSyncStatus('online');
+    // Pull inicial: garante state fresco quando conecta
+    schedulePull();
+    // Heartbeat
+    if(_wsHeartbeatTimer)clearInterval(_wsHeartbeatTimer);
+    _wsHeartbeatTimer=setInterval(()=>{
+      if(_wsConn&&_wsConn.readyState===WebSocket.OPEN){
+        try{_wsConn.send(JSON.stringify({type:'ping'}))}catch(e){}
+      }
+    },25000);
+  };
+
+  _wsConn.onmessage=(ev)=>{
+    let msg;try{msg=JSON.parse(ev.data)}catch(e){return}
+    if(msg.type==='hello'){
+      console.log('[rt] hello',msg);
+    }else if(msg.type==='state:changed'){
+      // Outro device alterou o state: pull
+      if(msg.originDeviceId===getDeviceId())return; // echo do nosso próprio push
+      schedulePull();
+    }else if(msg.type==='presence'){
+      const el=document.getElementById('sync-indicator');
+      if(el&&msg.count>1)el.title=`Sincronizado em tempo real · ${msg.count} dispositivos online`;
+    }else if(msg.type==='error'){
+      console.warn('[rt] server error',msg);
+      setSyncStatus('error',msg.code);
+    }
+  };
+
+  _wsConn.onerror=(e)=>{console.warn('[rt] ws error',e)};
+  _wsConn.onclose=(ev)=>{
+    if(_wsHeartbeatTimer){clearInterval(_wsHeartbeatTimer);_wsHeartbeatTimer=null}
+    _wsConn=null;
+    if(!cloudConfigured()){setSyncStatus('disabled');return}
+    setSyncStatus('offline');
+    if(ev.code!==1008)scheduleRtReconnect(); // 1008 = auth fail, não retentar
+  };
+}
+
+function scheduleRtReconnect(){
+  if(_wsReconnectTimer)clearTimeout(_wsReconnectTimer);
+  const delays=[1000,2000,5000,15000,30000,60000];
+  const delay=delays[Math.min(_wsReconnectAttempt,delays.length-1)];
+  _wsReconnectAttempt++;
+  _wsReconnectTimer=setTimeout(()=>rtConnect(),delay);
+}
+
+function rtDisconnect(){
+  if(_wsReconnectTimer){clearTimeout(_wsReconnectTimer);_wsReconnectTimer=null}
+  if(_wsHeartbeatTimer){clearInterval(_wsHeartbeatTimer);_wsHeartbeatTimer=null}
+  if(_wsConn){try{_wsConn.close(1000,'client disconnect')}catch(e){}_wsConn=null}
+  setSyncStatus('disabled');
+}
+
+// Push debounced — chamado de saveState. Só sobe quando configurado.
+function scheduleCloudPush(){
+  if(!cloudConfigured())return;
+  if(_wsPushTimer)clearTimeout(_wsPushTimer);
+  _wsPushTimer=setTimeout(()=>autoPushNow().catch(()=>{}),SYNC_DEBOUNCE_MS);
+}
+
+async function autoPushNow(){
+  if(!cloudConfigured())return;
+  if(_wsSyncInFlight)return;
+  _wsSyncInFlight=true;
+  setSyncStatus('syncing','enviando...');
+  try{
+    const{cloud,...dataNoCloud}=state;
+    await cloudFetch('/api/data?device='+encodeURIComponent(getDeviceId()),{
+      method:'POST',
+      headers:{'X-Device-Id':getDeviceId()},
+      body:JSON.stringify({data:dataNoCloud}),
+    });
+    state.cloud.lastSync=Date.now();
+    _wsLastPushAt=Date.now();
+    try{localStorage.setItem(STORAGE_KEY,JSON.stringify(state))}catch(e){}
+    setSyncStatus(_wsConn&&_wsConn.readyState===WebSocket.OPEN?'online':'offline');
+    if(typeof renderCloudStatus==='function')renderCloudStatus();
+  }catch(e){
+    console.warn('[rt] push failed',e.message);
+    setSyncStatus('error',e.message);
+  }finally{
+    _wsSyncInFlight=false;
+  }
+}
+
+// Pull debounced — chamado quando WS notifica mudança remota
+function schedulePull(){
+  if(_wsPullTimer)clearTimeout(_wsPullTimer);
+  _wsPullTimer=setTimeout(()=>autoPullNow().catch(()=>{}),SYNC_PULL_DEBOUNCE_MS);
+}
+
+async function autoPullNow(){
+  if(!cloudConfigured())return;
+  if(_wsSyncInFlight)return;
+  // Não puxa se acabamos de empurrar (echo guard adicional)
+  if(Date.now()-_wsLastPushAt<1000)return;
+  _wsSyncInFlight=true;
+  setSyncStatus('syncing','baixando...');
+  try{
+    const r=await cloudFetch('/api/data');
+    const{data,updated_at}=await r.json();
+    if(!data){setSyncStatus('online');_wsSyncInFlight=false;return}
+    // Se o updated_at remoto é mais antigo que nosso último push, ignora (evita rollback)
+    if(updated_at&&_wsLastPushAt&&updated_at<_wsLastPushAt){_wsSyncInFlight=false;setSyncStatus('online');return}
+    const cloudKeep=state.cloud;
+    const authKeep=state.auth;
+    Object.assign(state,data);
+    state.cloud=cloudKeep;
+    if(authKeep)state.auth=authKeep;
+    state.cloud.lastSync=Date.now();
+    try{localStorage.setItem(STORAGE_KEY,JSON.stringify(state))}catch(e){}
+    bindHeader();
+    if(typeof renderAll==='function')await renderAll();
+    setSyncStatus('online','recebido de outro dispositivo');
+    toast('🔄 Atualizado por outro dispositivo');
+  }catch(e){
+    console.warn('[rt] pull failed',e.message);
+    setSyncStatus('error',e.message);
+  }finally{
+    _wsSyncInFlight=false;
+  }
+}
+
 // ===== Auth (multi-tenant SaaS — Login/Signup) =====
 async function authSignup(email,password,name){
   if(!cloudConfigured())throw new Error('Configure URL do servidor primeiro');
@@ -3813,8 +4017,8 @@ function bindCloudInputs(){
   if(!u||!t)return;
   u.value=state.cloud?.url||'';
   t.value=state.cloud?.token||'';
-  u.addEventListener('change',()=>{state.cloud.url=u.value.trim();saveState();renderCloudStatus()});
-  t.addEventListener('change',()=>{state.cloud.token=t.value.trim();saveState();renderCloudStatus()});
+  u.addEventListener('change',()=>{state.cloud.url=u.value.trim();saveState();renderCloudStatus();rtDisconnect();if(cloudConfigured())rtConnect()});
+  t.addEventListener('change',()=>{state.cloud.token=t.value.trim();saveState();renderCloudStatus();rtDisconnect();if(cloudConfigured())rtConnect()});
 }
 
 function renderCloudStatus(){
diff --git a/server/src/index.js b/server/src/index.js
index b3a5d1f..05a0294 100644
--- a/server/src/index.js
+++ b/server/src/index.js
@@ -1,4 +1,5 @@
 import express from 'express';
+import http from 'node:http';
 import multer from 'multer';
 import rateLimit from 'express-rate-limit';
 import path from 'node:path';
@@ -9,6 +10,7 @@ import { dispatchAlarm, dispatchTest, listConfiguredChannels } from './notificat
 import { validate, setStateSchema, updateZonesSchema, signupSchema, loginSchema, checkoutSchema } from './schemas/index.js';
 import { hashPassword, verifyPassword, signAccessToken, signRefreshToken, verifyToken, PLANS, planFeatures } from './auth.js';
 import * as billing from './billing.js';
+import { initRealtime, broadcastStateChange, getOnlineCount } from './realtime.js';
 
 const __dirname = path.dirname(fileURLToPath(import.meta.url));
 const PORT = parseInt(process.env.PORT || '3000');
@@ -264,7 +266,7 @@ app.get('/.well-known/assetlinks.json', (req, res) => {
 });
 
 // Atalho: /apk redireciona pra última APK release no Forgejo
-const LATEST_APK_URL = 'https://git.pontualtech.work/karlao/shivao-projeto/releases/download/v1.4.1/Shivao-v1.4.1.apk';
+const LATEST_APK_URL = 'https://git.pontualtech.work/karlao/shivao-projeto/releases/download/v1.5.0/Shivao-v1.5.0.apk';
 app.get('/apk', (req, res) => res.redirect(302, LATEST_APK_URL));
 
 // Página A4 imprimível com QR Code + instruções (cola no barco/marina)
@@ -565,7 +567,10 @@ app.post('/api/data', requireAuth, validate(setStateSchema), (req, res) => {
   const { data } = req.body;
   const ts = db.setState(req.user.id, data);
   db.audit(req.user.id, 'state_set', 'state', null, { bytes: JSON.stringify(data).length }, req.ip);
-  res.json({ ok: true, updated_at: ts });
+  // Notifica outros devices do mesmo user em tempo real (não bloqueia resposta)
+  const originDeviceId = req.headers['x-device-id'] || req.query.device || null;
+  broadcastStateChange(req.user.id, { kind: 'state', updated_at: ts, originDeviceId });
+  res.json({ ok: true, updated_at: ts, online_devices: getOnlineCount(req.user.id) });
 });
 
 // --- Media ---
@@ -920,7 +925,10 @@ async function checkDeadman() {
 setInterval(checkDeadman, 30000); // check every 30s
 
 // ==== Start ====
-app.listen(PORT, () => {
+const httpServer = http.createServer(app);
+initRealtime(httpServer);
+
+httpServer.listen(PORT, () => {
   console.log(`Shivao Cloud rodando em :${PORT}`);
   console.log(`Canais configurados: ${listConfiguredChannels().join(', ') || '(nenhum!)'}`);
   console.log(`Dead-man switch: ${HEARTBEAT_TIMEOUT/1000}s`);
diff --git a/server/src/realtime.js b/server/src/realtime.js
new file mode 100644
index 0000000..9237cdd
--- /dev/null
+++ b/server/src/realtime.js
@@ -0,0 +1,126 @@
+// Realtime sync via WebSocket — broadcast state-change notifications between devices of the same user.
+// Cliente reage à notificação fazendo pull do estado via REST. Sem entity-level diffing.
+
+import { WebSocketServer } from 'ws';
+import { verifyToken } from './auth.js';
+
+const TOKEN = process.env.BOAT_TOKEN;
+const HEARTBEAT_INTERVAL = 30000;
+
+// Map<userId, Set<WebSocket>>
+const clientsByUser = new Map();
+
+function addClient(userId, ws) {
+  if (!clientsByUser.has(userId)) clientsByUser.set(userId, new Set());
+  clientsByUser.get(userId).add(ws);
+}
+
+function removeClient(userId, ws) {
+  const set = clientsByUser.get(userId);
+  if (!set) return;
+  set.delete(ws);
+  if (set.size === 0) clientsByUser.delete(userId);
+}
+
+// Resolve um token (JWT ou BOAT_TOKEN) → userId. Retorna null se inválido.
+function authenticateToken(token) {
+  if (!token) return null;
+  if (token === TOKEN) return 1; // legacy single-tenant
+  const payload = verifyToken(token);
+  if (!payload || payload.type !== 'access' || !payload.uid) return null;
+  return payload.uid;
+}
+
+export function initRealtime(httpServer) {
+  const wss = new WebSocketServer({ server: httpServer, path: '/ws' });
+
+  wss.on('connection', (ws, req) => {
+    const url = new URL(req.url, `http://${req.headers.host}`);
+    const token = url.searchParams.get('token') || '';
+    const deviceId = url.searchParams.get('device') || ('anon-' + Math.random().toString(36).slice(2, 8));
+    const userId = authenticateToken(token);
+
+    if (!userId) {
+      ws.send(JSON.stringify({ type: 'error', code: 'auth_failed' }));
+      ws.close(1008, 'auth failed');
+      return;
+    }
+
+    ws.userId = userId;
+    ws.deviceId = deviceId;
+    ws.isAlive = true;
+    addClient(userId, ws);
+
+    ws.send(JSON.stringify({ type: 'hello', userId, deviceId, ts: Date.now() }));
+
+    // Quantos devices estão online pro mesmo user
+    broadcastPresence(userId);
+
+    ws.on('pong', () => { ws.isAlive = true; });
+
+    ws.on('message', (raw) => {
+      // Cliente pode mandar pings explícitos ou notificações. Ignoramos qualquer outra coisa.
+      try {
+        const msg = JSON.parse(raw.toString());
+        if (msg.type === 'ping') {
+          ws.send(JSON.stringify({ type: 'pong', ts: Date.now() }));
+        }
+      } catch (e) { /* ignore */ }
+    });
+
+    ws.on('close', () => {
+      removeClient(userId, ws);
+      broadcastPresence(userId);
+    });
+
+    ws.on('error', (err) => {
+      console.warn('[ws] error', err.message);
+    });
+  });
+
+  // Heartbeat: drop dead connections
+  const heartbeat = setInterval(() => {
+    wss.clients.forEach((ws) => {
+      if (ws.isAlive === false) return ws.terminate();
+      ws.isAlive = false;
+      try { ws.ping(); } catch (e) {}
+    });
+  }, HEARTBEAT_INTERVAL);
+
+  wss.on('close', () => clearInterval(heartbeat));
+
+  console.log('[ws] WebSocket server attached at /ws');
+  return wss;
+}
+
+// Notifica todos os devices do user (exceto o que originou) que o estado mudou.
+// payload: { kind: 'state'|'pending'|'trip'|..., ts, originDeviceId? }
+export function broadcastStateChange(userId, payload = {}) {
+  const set = clientsByUser.get(userId);
+  if (!set) return;
+  const msg = JSON.stringify({
+    type: 'state:changed',
+    ts: Date.now(),
+    ...payload,
+  });
+  for (const ws of set) {
+    if (ws.readyState !== ws.OPEN) continue;
+    if (payload.originDeviceId && ws.deviceId === payload.originDeviceId) continue;
+    try { ws.send(msg); } catch (e) {}
+  }
+}
+
+function broadcastPresence(userId) {
+  const set = clientsByUser.get(userId);
+  if (!set) return;
+  const msg = JSON.stringify({ type: 'presence', count: set.size, ts: Date.now() });
+  for (const ws of set) {
+    if (ws.readyState === ws.OPEN) {
+      try { ws.send(msg); } catch (e) {}
+    }
+  }
+}
+
+export function getOnlineCount(userId) {
+  return clientsByUser.get(userId)?.size || 0;
+}