diff --git a/apps/chat/apps/web/src/lib/components/Toast.svelte b/apps/chat/apps/web/src/lib/components/Toast.svelte
new file mode 100644
index 000000000..af43a277e
--- /dev/null
+++ b/apps/chat/apps/web/src/lib/components/Toast.svelte
@@ -0,0 +1,63 @@
+<script lang="ts">
+	import { toastStore, type Toast } from '$lib/stores/toast.svelte';
+	import { X, CheckCircle, XCircle, Warning, Info } from '@manacore/shared-icons';
+
+	let toasts = $derived(toastStore.toasts);
+
+	const icons = {
+		success: CheckCircle,
+		error: XCircle,
+		warning: Warning,
+		info: Info,
+	};
+
+	const colors = {
+		success: 'bg-green-500/90 text-white',
+		error: 'bg-destructive/90 text-destructive-foreground',
+		warning: 'bg-amber-500/90 text-white',
+		info: 'bg-primary/90 text-primary-foreground',
+	};
+
+	function handleDismiss(id: string) {
+		toastStore.dismiss(id);
+	}
+</script>
+
+{#if toasts.length > 0}
+	<div class="fixed bottom-6 right-6 z-[100] flex flex-col gap-3 max-w-sm">
+		{#each toasts as toast (toast.id)}
+			{@const Icon = icons[toast.type]}
+			<div
+				class="flex items-start gap-3 px-4 py-3 rounded-xl shadow-lg backdrop-blur-xl border border-white/20 animate-slide-in {colors[toast.type]}"
+				role="alert"
+			>
+				<Icon size={20} weight="fill" class="flex-shrink-0 mt-0.5" />
+				<p class="flex-1 text-sm font-medium">{toast.message}</p>
+				<button
+					onclick={() => handleDismiss(toast.id)}
+					class="flex-shrink-0 p-1 rounded-lg hover:bg-white/20 transition-colors"
+					aria-label="Schließen"
+				>
+					<X size={16} weight="bold" />
+				</button>
+			</div>
+		{/each}
+	</div>
+{/if}
+
+<style>
+	@keyframes slide-in {
+		from {
+			opacity: 0;
+			transform: translateX(100%);
+		}
+		to {
+			opacity: 1;
+			transform: translateX(0);
+		}
+	}
+
+	.animate-slide-in {
+		animation: slide-in 0.3s ease-out;
+	}
+</style>
diff --git a/apps/chat/apps/web/src/lib/stores/conversations.svelte.ts b/apps/chat/apps/web/src/lib/stores/conversations.svelte.ts
index 1fb0cf9a4..912f8676b 100644
--- a/apps/chat/apps/web/src/lib/stores/conversations.svelte.ts
+++ b/apps/chat/apps/web/src/lib/stores/conversations.svelte.ts
@@ -3,6 +3,7 @@
  */
 
 import { conversationService } from '$lib/services/conversation';
+import { toastStore } from './toast.svelte';
 import type { Conversation } from '@chat/types';
 
 // State
@@ -36,7 +37,9 @@ export const conversationsStore = {
 		try {
 			conversations = await conversationService.getConversations(spaceId);
 		} catch (e) {
-			error = e instanceof Error ? e.message : 'Failed to load conversations';
+			const message = e instanceof Error ? e.message : 'Konversationen konnten nicht geladen werden';
+			error = message;
+			toastStore.error(message);
 			conversations = [];
 		} finally {
 			isLoading = false;
@@ -53,7 +56,9 @@ export const conversationsStore = {
 		try {
 			archivedConversations = await conversationService.getArchivedConversations();
 		} catch (e) {
-			error = e instanceof Error ? e.message : 'Failed to load archived conversations';
+			const message = e instanceof Error ? e.message : 'Archivierte Konversationen konnten nicht geladen werden';
+			error = message;
+			toastStore.error(message);
 			archivedConversations = [];
 		} finally {
 			isLoading = false;
diff --git a/apps/chat/apps/web/src/lib/stores/toast.svelte.ts b/apps/chat/apps/web/src/lib/stores/toast.svelte.ts
new file mode 100644
index 000000000..af686ceab
--- /dev/null
+++ b/apps/chat/apps/web/src/lib/stores/toast.svelte.ts
@@ -0,0 +1,100 @@
+/**
+ * Toast Store - Centralized notification system using Svelte 5 runes
+ */
+
+export type ToastType = 'success' | 'error' | 'warning' | 'info';
+
+export interface Toast {
+	id: string;
+	type: ToastType;
+	message: string;
+	duration: number;
+}
+
+// State
+let toasts = $state<Toast[]>([]);
+
+// Auto-incrementing ID
+let nextId = 0;
+
+function generateId(): string {
+	return `toast-${++nextId}-${Date.now()}`;
+}
+
+export const toastStore = {
+	// Getter for reading toasts
+	get toasts() {
+		return toasts;
+	},
+
+	/**
+	 * Show a toast notification
+	 */
+	show(message: string, type: ToastType = 'info', duration: number = 4000) {
+		const id = generateId();
+		const toast: Toast = { id, type, message, duration };
+
+		toasts = [...toasts, toast];
+
+		// Auto-remove after duration
+		if (duration > 0) {
+			setTimeout(() => {
+				this.dismiss(id);
+			}, duration);
+		}
+
+		return id;
+	},
+
+	/**
+	 * Show success toast
+	 */
+	success(message: string, duration?: number) {
+		return this.show(message, 'success', duration);
+	},
+
+	/**
+	 * Show error toast
+	 */
+	error(message: string, duration: number = 6000) {
+		return this.show(message, 'error', duration);
+	},
+
+	/**
+	 * Show warning toast
+	 */
+	warning(message: string, duration?: number) {
+		return this.show(message, 'warning', duration);
+	},
+
+	/**
+	 * Show info toast
+	 */
+	info(message: string, duration?: number) {
+		return this.show(message, 'info', duration);
+	},
+
+	/**
+	 * Dismiss a specific toast
+	 */
+	dismiss(id: string) {
+		toasts = toasts.filter((t) => t.id !== id);
+	},
+
+	/**
+	 * Dismiss all toasts
+	 */
+	dismissAll() {
+		toasts = [];
+	},
+};
+
+/**
+ * Helper function for API error handling
+ * Use this in services/stores to show user-friendly error messages
+ */
+export function handleApiError(error: unknown, fallbackMessage: string = 'Ein Fehler ist aufgetreten'): string {
+	const message = error instanceof Error ? error.message : fallbackMessage;
+	toastStore.error(message);
+	return message;
+}
diff --git a/apps/chat/apps/web/src/routes/+layout.svelte b/apps/chat/apps/web/src/routes/+layout.svelte
index 6123a0073..cb7ce45ce 100644
--- a/apps/chat/apps/web/src/routes/+layout.svelte
+++ b/apps/chat/apps/web/src/routes/+layout.svelte
@@ -2,6 +2,7 @@
 	import '../app.css';
 	import { onMount } from 'svelte';
 	import { theme } from '$lib/stores/theme';
+	import Toast from '$lib/components/Toast.svelte';
 
 	let { children } = $props();
 
@@ -14,3 +15,6 @@
 <div class="min-h-screen bg-background text-foreground">
 	{@render children()}
 </div>
+
+<!-- Global Toast notifications -->
+<Toast />
diff --git a/docker-compose.dev.yml b/docker-compose.dev.yml
index f3adfed32..606309043 100644
--- a/docker-compose.dev.yml
+++ b/docker-compose.dev.yml
@@ -68,6 +68,7 @@ services:
       CORS_ORIGINS: ${CORS_ORIGINS:-http://localhost:3000,http://localhost:5173,http://localhost:8081}
       CREDITS_SIGNUP_BONUS: ${CREDITS_SIGNUP_BONUS:-150}
       CREDITS_DAILY_FREE: ${CREDITS_DAILY_FREE:-5}
+      GOOGLE_GENAI_API_KEY: ${GOOGLE_GENAI_API_KEY}
     depends_on:
       postgres:
         condition: service_healthy