diff --git a/apps/ui/src/components/layout/sidebar/components/automaker-logo.tsx b/apps/ui/src/components/layout/sidebar/components/automaker-logo.tsx
index 5f498449..2a7363f2 100644
--- a/apps/ui/src/components/layout/sidebar/components/automaker-logo.tsx
+++ b/apps/ui/src/components/layout/sidebar/components/automaker-logo.tsx
@@ -1,13 +1,30 @@
 import type { NavigateOptions } from '@tanstack/react-router';
 import { cn } from '@/lib/utils';
+import { useOSDetection } from '@/hooks/use-os-detection';
 
 interface AutomakerLogoProps {
   sidebarOpen: boolean;
   navigate: (opts: NavigateOptions) => void;
 }
 
+function getOSAbbreviation(os: string): string {
+  switch (os) {
+    case 'mac':
+      return 'M';
+    case 'windows':
+      return 'W';
+    case 'linux':
+      return 'L';
+    default:
+      return '?';
+  }
+}
+
 export function AutomakerLogo({ sidebarOpen, navigate }: AutomakerLogoProps) {
   const appVersion = typeof __APP_VERSION__ !== 'undefined' ? __APP_VERSION__ : '0.0.0';
+  const { os } = useOSDetection();
+  const appMode = import.meta.env.VITE_APP_MODE || '?';
+  const versionSuffix = `${getOSAbbreviation(os)}${appMode}`;
 
   return (
     <div
@@ -69,7 +86,7 @@ export function AutomakerLogo({ sidebarOpen, navigate }: AutomakerLogoProps) {
           </g>
         </svg>
         <span className="text-[0.625rem] text-muted-foreground leading-none font-medium">
-          v{appVersion}
+          v{appVersion} {versionSuffix}
         </span>
       </div>
 
@@ -125,7 +142,7 @@ export function AutomakerLogo({ sidebarOpen, navigate }: AutomakerLogoProps) {
             </span>
           </div>
           <span className="text-[0.625rem] text-muted-foreground leading-none font-medium ml-[38.8px]">
-            v{appVersion}
+            v{appVersion} {versionSuffix}
           </span>
         </div>
       )}
diff --git a/apps/ui/src/hooks/use-os-detection.ts b/apps/ui/src/hooks/use-os-detection.ts
index a7bcf68b..7f0282a7 100644
--- a/apps/ui/src/hooks/use-os-detection.ts
+++ b/apps/ui/src/hooks/use-os-detection.ts
@@ -10,11 +10,12 @@ export interface OSDetectionResult {
 }
 
 function detectOS(): OperatingSystem {
-  // Check Electron's process.platform first (most reliable in Electron apps)
-  if (typeof process !== 'undefined' && process.platform) {
-    if (process.platform === 'darwin') return 'mac';
-    if (process.platform === 'win32') return 'windows';
-    if (process.platform === 'linux') return 'linux';
+  // Check Electron's exposed platform first (via preload contextBridge)
+  if (typeof window !== 'undefined' && window.electronAPI?.platform) {
+    const platform = window.electronAPI.platform;
+    if (platform === 'darwin') return 'mac';
+    if (platform === 'win32') return 'windows';
+    if (platform === 'linux') return 'linux';
   }
 
   if (typeof navigator === 'undefined') {
diff --git a/apps/ui/src/types/electron.d.ts b/apps/ui/src/types/electron.d.ts
index 6388e7a5..fc64f375 100644
--- a/apps/ui/src/types/electron.d.ts
+++ b/apps/ui/src/types/electron.d.ts
@@ -466,6 +466,10 @@ export interface AutoModeAPI {
 }
 
 export interface ElectronAPI {
+  // Platform info (exposed from preload)
+  platform?: 'darwin' | 'win32' | 'linux';
+  isElectron?: boolean;
+
   ping: () => Promise<string>;
   getApiKey?: () => Promise<string | null>;
   quit?: () => Promise<void>;
diff --git a/apps/ui/src/vite-env.d.ts b/apps/ui/src/vite-env.d.ts
index 04745bb1..2ed837a0 100644
--- a/apps/ui/src/vite-env.d.ts
+++ b/apps/ui/src/vite-env.d.ts
@@ -2,7 +2,7 @@
 
 interface ImportMetaEnv {
   readonly VITE_SERVER_URL?: string;
-  // Add other VITE_ prefixed env vars here as needed
+  readonly VITE_APP_MODE?: '1' | '2' | '3' | '4';
 }
 
 // Extend ImportMeta to include env property
diff --git a/dev.mjs b/dev.mjs
index 289090c6..6d137d23 100644
--- a/dev.mjs
+++ b/dev.mjs
@@ -133,6 +133,7 @@ async function main() {
           env: {
             TEST_PORT: String(webPort),
             VITE_SERVER_URL: `http://localhost:${serverPort}`,
+            VITE_APP_MODE: '1',
           },
         },
         __dirname
@@ -159,6 +160,7 @@ async function main() {
             PORT: String(serverPort),
             VITE_SERVER_URL: `http://localhost:${serverPort}`,
             CORS_ORIGIN: corsOriginEnv,
+            VITE_APP_MODE: '2',
           },
         },
         __dirname
diff --git a/docker-compose.dev.yml b/docker-compose.dev.yml
index c3098e8b..28ef08da 100644
--- a/docker-compose.dev.yml
+++ b/docker-compose.dev.yml
@@ -103,6 +103,7 @@ services:
       - VITE_SERVER_URL=http://localhost:3008
       - TEST_PORT=3007
       - VITE_SKIP_ELECTRON=true
+      - VITE_APP_MODE=3
     volumes:
       # Mount source code for live reload
       - .:/app:cached
diff --git a/scripts/launcher-utils.mjs b/scripts/launcher-utils.mjs
index 69aa036f..1dcdab7f 100644
--- a/scripts/launcher-utils.mjs
+++ b/scripts/launcher-utils.mjs
@@ -986,6 +986,7 @@ export async function launchDockerDevServerContainer({ baseDir, processes }) {
       SKIP_EMBEDDED_SERVER: 'true',
       PORT: '3008',
       VITE_SERVER_URL: 'http://localhost:3008',
+      VITE_APP_MODE: '4',
     },
   });