diff --git a/apps/backend/src/adapters/inbound/websocket/robot.gateway.ts b/apps/backend/src/adapters/inbound/websocket/robot.gateway.ts
index 6a2de95..0e9a806 100644
--- a/apps/backend/src/adapters/inbound/websocket/robot.gateway.ts
+++ b/apps/backend/src/adapters/inbound/websocket/robot.gateway.ts
@@ -11,6 +11,7 @@ import { Inject, Logger, forwardRef } from '@nestjs/common';
 import { JwtService } from '@nestjs/jwt';
 import { Server, Socket } from 'socket.io';
 import { DeviceService } from '../../../core/services/device.service';
+import { DeviceStatus } from '../../../core/domain/entities/device.entity';
 import { JwtPayload } from '../rest/auth/strategies/jwt.strategy';
 import { IConversationPort, CONVERSATION_PORT } from '../../../core/ports/inbound/conversation.port';
 import { IDeviceGatewayPort } from '../../../core/ports/outbound/device-gateway.port';
@@ -76,7 +77,7 @@ export class RobotGateway implements OnGatewayConnection, OnGatewayDisconnect, I
       client.data.homeId = payload.homeId;
 
       this.connectedDevices.set(payload.sub, client);
-      await this.deviceService.updateLastSeen(payload.sub);
+      await this.deviceService.setStatus(payload.sub, DeviceStatus.ONLINE);
 
       this.logger.log(`Device connected: ${device.name} (${payload.sub})`);
       client.emit('status', { state: 'idle' as RobotState });
@@ -86,11 +87,16 @@ export class RobotGateway implements OnGatewayConnection, OnGatewayDisconnect, I
     }
   }
 
-  handleDisconnect(client: AuthenticatedSocket) {
+  async handleDisconnect(client: AuthenticatedSocket) {
     const deviceId = client.data?.deviceId;
     if (deviceId) {
       this.connectedDevices.delete(deviceId);
       this.conversationPort.interrupt(deviceId);
+      try {
+        await this.deviceService.setStatus(deviceId, DeviceStatus.OFFLINE);
+      } catch (err) {
+        this.logger.warn(`Failed to mark ${deviceId} offline: ${String(err)}`);
+      }
       this.logger.log(`Device disconnected: ${deviceId}`);
     }
   }
diff --git a/apps/backend/src/core/services/device.service.ts b/apps/backend/src/core/services/device.service.ts
index 05897cd..425badd 100644
--- a/apps/backend/src/core/services/device.service.ts
+++ b/apps/backend/src/core/services/device.service.ts
@@ -2,7 +2,7 @@ import { Injectable } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
 import { Repository } from 'typeorm';
 import * as bcrypt from 'bcrypt';
-import { Device } from '../domain/entities/device.entity';
+import { Device, DeviceStatus } from '../domain/entities/device.entity';
 
 @Injectable()
 export class DeviceService {
@@ -37,4 +37,11 @@ export class DeviceService {
   async updateLastSeen(id: string): Promise<void> {
     await this.deviceRepository.update(id, { lastSeenAt: new Date() });
   }
+
+  async setStatus(id: string, status: DeviceStatus): Promise<void> {
+    await this.deviceRepository.update(id, {
+      status,
+      lastSeenAt: new Date(),
+    });
+  }
 }