diff --git a/shop/app/actions/checkout.ts b/shop/app/actions/checkout.ts
index 6ea1540..5e6477b 100644
--- a/shop/app/actions/checkout.ts
+++ b/shop/app/actions/checkout.ts
@@ -4,6 +4,10 @@ import { createClient } from '@/lib/supabase/server';
 import { createHash } from 'crypto';
 import { buildCustomerSnapshot, buildOrderSnapshot } from '@/lib/license-transform';
 import { getProducts, getCategories } from '@/lib/actions/products';
+import { sendMail } from '@/utils/mail';
+import { renderToBuffer } from '@react-pdf/renderer';
+import React from 'react';
+import { InvoicePDF } from '@/components/invoice-pdf';
 
 function generateOrderNumber(prefix: 'BE' | 'AE' = 'AE'): string {
   const year = new Date().getFullYear();
@@ -16,6 +20,55 @@ function hashOrderPayload(endCustomerId: string, items: any[]): string {
   return createHash('sha256').update(str).digest('hex');
 }
 
+// Asynchroner Hintergrund-Worker für Post-Processing (PDF-Erstellung und E-Mail)
+async function triggerPostProcessing(orderId: string, supabase: any, customerSnapshot: any, orderSnapshot: any, type: string, email: string) {
+  try {
+    const { data: order, error } = await supabase
+      .from('orders')
+      .select('*')
+      .eq('id', orderId)
+      .single();
+
+    if (error || !order) {
+      console.error(`Post-Processing failed: Order ${orderId} not found`);
+      return;
+    }
+
+    // PDF generieren
+    const buffer = await renderToBuffer(
+      React.createElement(InvoicePDF, {
+        order,
+        customer: customerSnapshot,
+        orderSnapshot,
+      })
+    );
+
+    const fileName = `ab_${order.id}.pdf`;
+    const { error: uploadError } = await supabase
+      .storage
+      .from('invoices')
+      .upload(fileName, buffer, { contentType: 'application/pdf', upsert: true });
+
+    if (!uploadError) {
+      await supabase.from('orders').update({ pdf_url: fileName }).eq('id', order.id);
+    } else {
+      console.error(`PDF Upload failed for order ${orderId}:`, uploadError);
+    }
+
+    // E-Mail versenden
+    if (email) {
+      await sendMail({
+        to: email,
+        subject: `Bestätigung Ihrer CASPOS-Anfrage ${order.order_number}`,
+        text: `Vielen Dank für Ihre Anfrage ${order.order_number}.`,
+        html: `<p>Vielen Dank für Ihre Anfrage <strong>${order.order_number}</strong>.</p>`
+      });
+    }
+  } catch (err) {
+    console.error(`Error in post-processing for order ${orderId}:`, err);
+  }
+}
+
 export async function checkoutAction(params: {
   items: any[];
   endCustomerId: string;
@@ -132,6 +185,13 @@ export async function checkoutAction(params: {
 
     if (orderError) throw orderError;
     orderIds.push(order.id);
+
+    // Entkoppeltes Post-Processing (asynchroner Aufruf)
+    if (user.email) {
+      Promise.resolve().then(() => {
+        triggerPostProcessing(order.id, supabase, customerSnapshot, orderSnapshot, type, user.email!);
+      });
+    }
   };
 
   await createOrderGroup(purchaseItems, 'purchase', 'invoice');