diff --git a/.phase12-state.json b/.phase12-state.json
index d170731..ddb0b52 100644
--- a/.phase12-state.json
+++ b/.phase12-state.json
@@ -1,8 +1,9 @@
 {
   "completed_features": [],
-  "current_feature": "time-rounding-rules",
+  "current_feature": "user-avatars",
   "started_at": "2026-05-23T06:33:48.406343",
   "attempted_features": [
-    "invoicing-stub"
+    "invoicing-stub",
+    "time-rounding-rules"
   ]
 }
\ No newline at end of file
diff --git a/GENERATION_LOG.md b/GENERATION_LOG.md
index 0622fef..6358375 100644
--- a/GENERATION_LOG.md
+++ b/GENERATION_LOG.md
@@ -1478,3 +1478,22 @@ src/index.ts(27,25): error TS2769: No overload matches this call.
   Overload 2 of 3, '(plugin: FastifyPluginAsync<{ limits: { fileSize: number; }; }, RawServerDefault, FastifyTypeProvider, FastifyBaseLogger>, opts?: FastifyRegisterOptions<...> | undefined): FastifyInstance<...> & PromiseLike<...>', gave the following error.
     Argument of type 'Promise<FastifyMultipartPlugin>' is not assignable to parameter of type 'FastifyPluginAsync<{ limits: { fileSize: number; }; }, RawServerDefault, FastifyTypeProvider, FastifyBaseLogger>'.
       Type 'Promise<FastifyMultipartPlugin>' provides no match for the signature '(instance: FastifyInstance<RawServerDefault, IncomingMessage, ServerResponse<IncomingMessage>, FastifyBaseLogger, FastifyTy
+- `06:36:29` **INFO**   Committed feature time-rounding-rules
+- `06:36:29` **INFO**   Pushed: rc=0
+
+## Phase-3 Feature: user-avatars (2026-05-23 06:36:29)
+
+- `06:36:29` **INFO** Description: Avatar-Component (Initialen-Badge) + überall einsetzen
+- `06:36:29` **INFO**   Generating apps/web/src/components/Avatar.tsx (Avatar-Component. Props: name (string), size? ('sm'|'md'|'lg', default…)
+- `06:36:41` **INFO**     wrote 1067 chars in 12.0s (attempt 1)
+- `06:36:41` **INFO**   Generating apps/web/src/components/Nav.tsx (ERWEITERT — füge <Avatar name={user.name} size='sm' /> links neben Log…)
+- `06:37:38` **INFO**     wrote 6000 chars in 56.9s (attempt 1)
+- `06:37:38` **INFO** Running tsc --noEmit on api…
+- `06:37:40` **WARN**   tsc errors:
+src/index.ts(27,25): error TS2769: No overload matches this call.
+  Overload 1 of 3, '(plugin: FastifyPluginCallback<{ limits: { fileSize: number; }; }, RawServerDefault, FastifyTypeProvider, FastifyBaseLogger>, opts?: FastifyRegisterOptions<...> | undefined): FastifyInstance<...> & PromiseLike<...>', gave the following error.
+    Argument of type 'Promise<FastifyMultipartPlugin>' is not assignable to parameter of type 'FastifyPluginCallback<{ limits: { fileSize: number; }; }, RawServerDefault, FastifyTypeProvider, FastifyBaseLogger>'.
+      Type 'Promise<FastifyMultipartPlugin>' provides no match for the signature '(instance: FastifyInstance<RawServerDefault, IncomingMessage, ServerResponse<IncomingMessage>, FastifyBaseLogger, FastifyTypeProvider>, opts: { ...; }, done: (err?: Error | undefined) => void): void'.
+  Overload 2 of 3, '(plugin: FastifyPluginAsync<{ limits: { fileSize: number; }; }, RawServerDefault, FastifyTypeProvider, FastifyBaseLogger>, opts?: FastifyRegisterOptions<...> | undefined): FastifyInstance<...> & PromiseLike<...>', gave the following error.
+    Argument of type 'Promise<FastifyMultipartPlugin>' is not assignable to parameter of type 'FastifyPluginAsync<{ limits: { fileSize: number; }; }, RawServerDefault, FastifyTypeProvider, FastifyBaseLogger>'.
+      Type 'Promise<FastifyMultipartPlugin>' provides no match for the signature '(instance: FastifyInstance<RawServerDefault, IncomingMessage, ServerResponse<IncomingMessage>, FastifyBaseLogger, FastifyTy
diff --git a/apps/web/src/components/Avatar.tsx b/apps/web/src/components/Avatar.tsx
new file mode 100644
index 0000000..f4840c1
--- /dev/null
+++ b/apps/web/src/components/Avatar.tsx
@@ -0,0 +1,45 @@
+import React from 'react';
+
+interface AvatarProps {
+  name: string;
+  size?: 'sm' | 'md' | 'lg';
+}
+
+const COLORS = [
+  'bg-orange-500',
+  'bg-blue-500',
+  'bg-emerald-500',
+  'bg-purple-500',
+  'bg-pink-500',
+];
+
+const SIZE_MAP = {
+  sm: 'w-8 h-8 text-xs',
+  md: 'w-10 h-10 text-sm',
+  lg: 'w-12 h-12 text-base',
+};
+
+export const Avatar: React.FC<AvatarProps> = ({ name, size = 'md' }) => {
+  const getInitials = (name: string) => {
+    const parts = name.trim().split(/\s+/);
+    if (parts.length === 1) return parts[0].substring(0, 2).toUpperCase();
+    return (parts[0][0] + parts[parts.length - 1][0]).toUpperCase();
+  };
+
+  const getColor = (name: string) => {
+    let hash = 0;
+    for (let i = 0; i < name.length; i++) {
+      hash = name.charCodeAt(i) + ((hash << 5) - hash);
+    }
+    const index = Math.abs(hash) % COLORS.length;
+    return COLORS[index];
+  };
+
+  return (
+    <div
+      className={`flex items-center justify-center rounded-full text-white font-medium ${SIZE_MAP[size]} ${getColor(name)}`}
+    >
+      {getInitials(name)}
+    </div>
+  );
+};
\ No newline at end of file
diff --git a/apps/web/src/components/Nav.tsx b/apps/web/src/components/Nav.tsx
index a264243..f724278 100644
--- a/apps/web/src/components/Nav.tsx
+++ b/apps/web/src/components/Nav.tsx
@@ -15,11 +15,13 @@ import {
   X,
   Zap,
   CreditCard,
-  Languages
+  Languages,
+  LogOut
 } from "lucide-react"
 import { useQuery } from "@tanstack/react-query"
 import { api } from "../lib/api"
 import { useTheme } from "../lib/theme"
+import Avatar from "./Avatar"
 
 export default function Nav() {
   const location = useLocation()
@@ -96,7 +98,7 @@ export default function Nav() {
             </div>
           </div>
 
-          <div className="flex items-center gap-2">
+          <div className="flex items-center gap-3">
             <button 
               onClick={toggleTheme}
               className="p-2 rounded-full text-gray-500 hover:bg-gray-100 dark:text-slate-400 dark:hover:bg-slate-800 transition-colors"
@@ -108,18 +110,31 @@ export default function Nav() {
             <div className="flex items-center gap-1 p-1 rounded-full bg-gray-100 dark:bg-slate-800 border border-gray-200 dark:border-slate-700">
               <button 
                 onClick={() => setLang('en')}
-                className={`px-2 py-1 text-[10px] font-bold rounded-full transition-all ${lang === 'en' ? 'bg-white dark:bg-slate-600 text-indigo-600 dark:text-white shadow-sm' : 'text-gray-500 dark:text-slate-400 hover:text-gray-700 dark:hover:text-slate-200'}`}
+                className={`px-2 py-1 text-[10px] font-bold rounded-full transition-colors ${lang === 'en' ? 'bg-white dark:bg-slate-700 text-indigo-600 dark:text-indigo-400 shadow-sm' : 'text-gray-500 dark:text-slate-400 hover:text-gray-700 dark:hover:text-slate-300'}`}
               >
                 EN
               </button>
               <button 
                 onClick={() => setLang('de')}
-                className={`px-2 py-1 text-[10px] font-bold rounded-full transition-all ${lang === 'de' ? 'bg-white dark:bg-slate-600 text-indigo-600 dark:text-white shadow-sm' : 'text-gray-500 dark:text-slate-400 hover:text-gray-700 dark:hover:text-slate-200'}`}
+                className={`px-2 py-1 text-[10px] font-bold rounded-full transition-colors ${lang === 'de' ? 'bg-white dark:bg-slate-700 text-indigo-600 dark:text-indigo-400 shadow-sm' : 'text-gray-500 dark:text-slate-400 hover:text-gray-700 dark:hover:text-slate-300'}`}
               >
                 DE
               </button>
             </div>
-            
+
+            <div className="flex items-center gap-3 pl-3 border-l border-gray-200 dark:border-slate-800">
+              {user && (
+                <Avatar name={user.name} size="sm" />
+              )}
+              <button 
+                onClick={() => api.logout()}
+                className="p-2 text-gray-500 hover:text-red-600 dark:text-slate-400 dark:hover:text-red-400 transition-colors"
+                title="Logout"
+              >
+                <LogOut className="w-5 h-5" />
+              </button>
+            </div>
+
             <button 
               onClick={() => setIsMobileMenuOpen(!isMobileMenuOpen)}
               className="md:hidden p-2 rounded-md text-gray-500 hover:bg-gray-100 dark:text-slate-400 dark:hover:bg-slate-800"