diff --git a/assets/js/layout/AppMenu.vue b/assets/js/layout/AppMenu.vue
index a793775..ad67c5f 100644
--- a/assets/js/layout/AppMenu.vue
+++ b/assets/js/layout/AppMenu.vue
@@ -1,11 +1,12 @@
 <script setup>
-import { ref } from 'vue';
+import { ref, onMounted } from 'vue';
 import { useAuthStore } from '../stores/auth';
 import AppMenuItem from './AppMenuItem.vue';
 
 const authStore = useAuthStore();
 
-const model = ref([
+// Core-Menü (immer vorhanden)
+const coreMenu = [
     {
         label: 'Home',
         items: [{ label: 'Dashboard', icon: 'pi pi-fw pi-home', to: '/' }]
@@ -17,18 +18,66 @@ const model = ref([
             { label: 'Projekte', icon: 'pi pi-fw pi-briefcase', to: '/projects' },
             { label: 'Tätigkeiten', icon: 'pi pi-fw pi-list-check', to: '/project-tasks' }
         ]
-    },
-    {
-        label: 'Administration',
-        visible: () => authStore.isAdmin,
-        items: [
-            { label: 'Projekt-Status', icon: 'pi pi-fw pi-tag', to: '/project-statuses' },
-            { label: 'Benutzerverwaltung', icon: 'pi pi-fw pi-user-edit', to: '/users' },
-            { label: 'Rollenverwaltung', icon: 'pi pi-fw pi-shield', to: '/roles' },
-            { label: 'Einstellungen', icon: 'pi pi-fw pi-cog', to: '/settings' }
-        ]
     }
-]);
+];
+
+// Administration-Menü (immer vorhanden)
+const adminMenu = {
+    label: 'Administration',
+    visible: () => authStore.isAdmin,
+    items: [
+        { label: 'Projekt-Status', icon: 'pi pi-fw pi-tag', to: '/project-statuses' },
+        { label: 'Benutzerverwaltung', icon: 'pi pi-fw pi-user-edit', to: '/users' },
+        { label: 'Rollenverwaltung', icon: 'pi pi-fw pi-shield', to: '/roles' },
+        { label: 'Einstellungen', icon: 'pi pi-fw pi-cog', to: '/settings' }
+    ]
+};
+
+// Dynamisches Menü (wird geladen)
+const model = ref([...coreMenu]);
+
+// Plugin-Menüs laden
+const loadPluginMenus = async () => {
+    try {
+        const response = await fetch('/api/plugin-menu/grouped');
+        const data = await response.json();
+
+        if (data.success && data.data) {
+            // Plugin-Menüs als eigene Gruppen hinzufügen
+            Object.entries(data.data).forEach(([groupLabel, items]) => {
+                // Konvertiere zu PrimeVue Menü-Format
+                const menuGroup = {
+                    label: groupLabel,
+                    items: items.map(item => ({
+                        label: item.label,
+                        icon: item.icon ? `pi pi-fw ${item.icon}` : 'pi pi-fw pi-circle',
+                        to: item.to,
+                        ...(item.items && { items: item.items }),
+                        // Wenn Permission definiert, prüfen
+                        ...(item.permission && {
+                            visible: () => authStore.hasPermission(item.permission)
+                        })
+                    }))
+                };
+
+                model.value.push(menuGroup);
+            });
+        }
+
+        // Administration-Menü am Ende hinzufügen
+        model.value.push(adminMenu);
+
+    } catch (error) {
+        console.error('Fehler beim Laden der Plugin-Menüs:', error);
+        // Fallback: Nur Core + Admin Menü
+        model.value = [...coreMenu, adminMenu];
+    }
+};
+
+// Beim Mount laden
+onMounted(() => {
+    loadPluginMenus();
+});
 </script>
 
 <template>
diff --git a/assets/js/router.js b/assets/js/router.js
index 9c1bea6..cdb380b 100644
--- a/assets/js/router.js
+++ b/assets/js/router.js
@@ -7,6 +7,7 @@ import ProjectStatusManagement from './views/ProjectStatusManagement.vue';
 import UserManagement from './views/UserManagement.vue';
 import RoleManagement from './views/RoleManagement.vue';
 import SettingsManagement from './views/SettingsManagement.vue';
+import InvoiceManagement from './views/InvoiceManagement.vue';
 
 const routes = [
     { path: '/', name: 'dashboard', component: Dashboard },
@@ -17,6 +18,8 @@ const routes = [
     { path: '/users', name: 'users', component: UserManagement, meta: { requiresAdmin: true } },
     { path: '/roles', name: 'roles', component: RoleManagement, meta: { requiresAdmin: true } },
     { path: '/settings', name: 'settings', component: SettingsManagement, meta: { requiresAdmin: true } },
+    // Billing Module Routes
+    { path: '/billing/invoices', name: 'invoices', component: InvoiceManagement, meta: { requiresPermission: { module: 'billing', action: 'view' } } },
 ];
 
 const router = createRouter({
diff --git a/assets/js/views/InvoiceForm.vue b/assets/js/views/InvoiceForm.vue
new file mode 100644
index 0000000..5c5c689
--- /dev/null
+++ b/assets/js/views/InvoiceForm.vue
@@ -0,0 +1,205 @@
+<template>
+    <div class="invoice-form">
+        <Message severity="info" v-if="!invoice">
+            Rechnungsformular (Phase 1 MVP - wird erweitert)
+        </Message>
+
+        <div class="grid p-fluid">
+            <!-- Rechnungsnummer -->
+            <div class="col-12 md:col-6">
+                <label for="invoiceNumber">Rechnungsnummer *</label>
+                <InputText id="invoiceNumber" v-model="form.invoiceNumber" required />
+            </div>
+
+            <!-- Status -->
+            <div class="col-12 md:col-6">
+                <label for="status">Status</label>
+                <Dropdown
+                    id="status"
+                    v-model="form.status"
+                    :options="statusOptions"
+                    option-label="label"
+                    option-value="value"
+                />
+            </div>
+
+            <!-- Kunde -->
+            <div class="col-12 md:col-6">
+                <label for="contact">Kunde *</label>
+                <Dropdown
+                    id="contact"
+                    v-model="form.contactId"
+                    :options="contacts"
+                    option-label="name"
+                    option-value="id"
+                    filter
+                    placeholder="Kunde auswählen"
+                />
+            </div>
+
+            <!-- Rechnungsdatum -->
+            <div class="col-12 md:col-6">
+                <label for="invoiceDate">Rechnungsdatum *</label>
+                <Calendar id="invoiceDate" v-model="form.invoiceDate" date-format="dd.mm.yy" />
+            </div>
+
+            <!-- Fälligkeitsdatum -->
+            <div class="col-12 md:col-6">
+                <label for="dueDate">Fälligkeitsdatum *</label>
+                <Calendar id="dueDate" v-model="form.dueDate" date-format="dd.mm.yy" />
+            </div>
+
+            <!-- Notizen -->
+            <div class="col-12">
+                <label for="notes">Notizen</label>
+                <Textarea id="notes" v-model="form.notes" rows="3" />
+            </div>
+
+            <!-- Positionen -->
+            <div class="col-12">
+                <h3>Rechnungspositionen</h3>
+                <DataTable :value="form.items" responsiveLayout="scroll">
+                    <Column field="description" header="Beschreibung">
+                        <template #body="slotProps">
+                            <Textarea v-model="slotProps.data.description" rows="2" class="w-full" />
+                        </template>
+                    </Column>
+                    <Column field="quantity" header="Menge">
+                        <template #body="slotProps">
+                            <InputNumber v-model="slotProps.data.quantity" :min-fraction-digits="2" class="w-full" />
+                        </template>
+                    </Column>
+                    <Column field="unitPrice" header="Einzelpreis">
+                        <template #body="slotProps">
+                            <InputNumber v-model="slotProps.data.unitPrice" mode="currency" currency="EUR" locale="de-DE" class="w-full" />
+                        </template>
+                    </Column>
+                    <Column field="taxRate" header="MwSt %">
+                        <template #body="slotProps">
+                            <Dropdown v-model="slotProps.data.taxRate" :options="taxRates" class="w-full" />
+                        </template>
+                    </Column>
+                    <Column header="Aktionen">
+                        <template #body="slotProps">
+                            <Button icon="pi pi-trash" text severity="danger" @click="removeItem(slotProps.index)" />
+                        </template>
+                    </Column>
+                </DataTable>
+
+                <Button label="Position hinzufügen" icon="pi pi-plus" text @click="addItem" class="mt-2" />
+            </div>
+        </div>
+
+        <!-- Actions -->
+        <div class="flex gap-2 mt-4">
+            <Button label="Speichern" icon="pi pi-check" @click="save" />
+            <Button label="Abbrechen" icon="pi pi-times" severity="secondary" text @click="cancel" />
+        </div>
+    </div>
+</template>
+
+<script setup>
+import { ref, onMounted } from 'vue'
+import InputText from 'primevue/inputtext'
+import Dropdown from 'primevue/dropdown'
+import Calendar from 'primevue/calendar'
+import Textarea from 'primevue/textarea'
+import Button from 'primevue/button'
+import DataTable from 'primevue/datatable'
+import Column from 'primevue/column'
+import InputNumber from 'primevue/inputnumber'
+import Message from 'primevue/message'
+
+const props = defineProps({
+    invoice: Object
+})
+
+const emit = defineEmits(['save', 'cancel'])
+
+const form = ref({
+    invoiceNumber: '',
+    status: 'draft',
+    contactId: null,
+    invoiceDate: new Date(),
+    dueDate: new Date(Date.now() + 14 * 24 * 60 * 60 * 1000), // +14 Tage
+    notes: '',
+    items: []
+})
+
+const contacts = ref([])
+
+const statusOptions = [
+    { label: 'Entwurf', value: 'draft' },
+    { label: 'Offen', value: 'open' },
+    { label: 'Bezahlt', value: 'paid' },
+    { label: 'Teilweise bezahlt', value: 'partial' },
+    { label: 'Überfällig', value: 'overdue' },
+    { label: 'Storniert', value: 'cancelled' }
+]
+
+const taxRates = ['0.00', '7.00', '19.00']
+
+onMounted(async () => {
+    // Load contacts
+    const response = await fetch('/api/contacts')
+    const data = await response.json()
+    contacts.value = data['hydra:member'] || []
+
+    // Load existing invoice data
+    if (props.invoice) {
+        form.value = { ...props.invoice }
+        if (props.invoice.invoiceDate) {
+            form.value.invoiceDate = new Date(props.invoice.invoiceDate)
+        }
+        if (props.invoice.dueDate) {
+            form.value.dueDate = new Date(props.invoice.dueDate)
+        }
+    }
+})
+
+const addItem = () => {
+    form.value.items.push({
+        description: '',
+        quantity: 1.00,
+        unitPrice: 0.00,
+        taxRate: '19.00'
+    })
+}
+
+const removeItem = (index) => {
+    form.value.items.splice(index, 1)
+}
+
+const save = async () => {
+    const method = props.invoice ? 'PUT' : 'POST'
+    const url = props.invoice ? `/api/invoices/${props.invoice.id}` : '/api/invoices'
+
+    const payload = {
+        invoiceNumber: form.value.invoiceNumber,
+        contact: `/api/contacts/${form.value.contactId}`,
+        status: form.value.status,
+        invoiceDate: form.value.invoiceDate.toISOString().split('T')[0],
+        dueDate: form.value.dueDate.toISOString().split('T')[0],
+        notes: form.value.notes,
+        items: form.value.items
+    }
+
+    await fetch(url, {
+        method,
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify(payload)
+    })
+
+    emit('save', form.value)
+}
+
+const cancel = () => {
+    emit('cancel')
+}
+</script>
+
+<style scoped>
+.invoice-form {
+    padding: 1rem;
+}
+</style>
diff --git a/assets/js/views/InvoiceManagement.vue b/assets/js/views/InvoiceManagement.vue
new file mode 100644
index 0000000..d94ed99
--- /dev/null
+++ b/assets/js/views/InvoiceManagement.vue
@@ -0,0 +1,281 @@
+<template>
+    <div class="card">
+        <h2>Rechnungsverwaltung</h2>
+
+        <CrudDataTable
+            title="Rechnungen"
+            :api-endpoint="`/api/invoices`"
+            :columns="columns"
+            :show-create-button="canCreate"
+            create-button-label="Neue Rechnung"
+            @create="openCreateDialog"
+            @edit="openEditDialog"
+            @delete="deleteInvoice"
+        >
+            <template #body="{ item }">
+                <Column field="invoiceNumber" header="Rechnungsnummer" sortable>
+                    <template #body="slotProps">
+                        <router-link :to="`/billing/invoices/${slotProps.data.id}`" class="text-primary">
+                            {{ slotProps.data.invoiceNumber }}
+                        </router-link>
+                    </template>
+                </Column>
+
+                <Column field="contact.name" header="Kunde" sortable>
+                    <template #body="slotProps">
+                        {{ slotProps.data.contact?.name || '-' }}
+                    </template>
+                </Column>
+
+                <Column field="invoiceDate" header="Rechnungsdatum" sortable>
+                    <template #body="slotProps">
+                        {{ formatDate(slotProps.data.invoiceDate) }}
+                    </template>
+                </Column>
+
+                <Column field="dueDate" header="Fälligkeitsdatum" sortable>
+                    <template #body="slotProps">
+                        {{ formatDate(slotProps.data.dueDate) }}
+                    </template>
+                </Column>
+
+                <Column field="total" header="Gesamtbetrag" sortable>
+                    <template #body="slotProps">
+                        {{ formatCurrency(slotProps.data.total) }}
+                    </template>
+                </Column>
+
+                <Column field="openAmount" header="Offen" sortable>
+                    <template #body="slotProps">
+                        {{ formatCurrency(slotProps.data.openAmount) }}
+                    </template>
+                </Column>
+
+                <Column field="status" header="Status" sortable>
+                    <template #body="slotProps">
+                        <Tag :value="getStatusLabel(slotProps.data.status)" :severity="getStatusSeverity(slotProps.data.status)" />
+                    </template>
+                </Column>
+
+                <Column :exportable="false" style="min-width:12rem">
+                    <template #body="slotProps">
+                        <div class="flex gap-2">
+                            <Button
+                                v-if="slotProps.data.pdfPath"
+                                icon="pi pi-file-pdf"
+                                outlined
+                                severity="secondary"
+                                @click="viewPDF(slotProps.data)"
+                                v-tooltip.top="'PDF anzeigen'"
+                            />
+                            <Button
+                                v-else
+                                icon="pi pi-upload"
+                                outlined
+                                severity="info"
+                                @click="uploadPDF(slotProps.data)"
+                                v-tooltip.top="'PDF hochladen'"
+                            />
+                            <Button
+                                icon="pi pi-money-bill"
+                                outlined
+                                severity="success"
+                                @click="addPayment(slotProps.data)"
+                                v-tooltip.top="'Zahlung hinzufügen'"
+                            />
+                            <Button
+                                icon="pi pi-pencil"
+                                outlined
+                                severity="info"
+                                @click="openEditDialog(slotProps.data)"
+                                v-tooltip.top="'Bearbeiten'"
+                            />
+                            <Button
+                                icon="pi pi-trash"
+                                outlined
+                                severity="danger"
+                                @click="deleteInvoice(slotProps.data)"
+                                v-tooltip.top="'Löschen'"
+                            />
+                        </div>
+                    </template>
+                </Column>
+            </template>
+        </CrudDataTable>
+
+        <!-- Create/Edit Dialog -->
+        <Dialog v-model:visible="dialogVisible" :header="dialogTitle" :modal="true" :style="{width: '70vw'}" :maximizable="true">
+            <InvoiceForm
+                v-if="dialogVisible"
+                :invoice="currentInvoice"
+                @save="saveInvoice"
+                @cancel="closeDialog"
+            />
+        </Dialog>
+
+        <!-- Payment Dialog -->
+        <Dialog v-model:visible="paymentDialogVisible" header="Zahlung hinzufügen" :modal="true" :style="{width: '40vw'}">
+            <PaymentForm
+                v-if="paymentDialogVisible"
+                :invoice="currentInvoice"
+                @save="savePayment"
+                @cancel="paymentDialogVisible = false"
+            />
+        </Dialog>
+
+        <!-- PDF Upload Dialog -->
+        <Dialog v-model:visible="pdfUploadDialogVisible" header="PDF hochladen" :modal="true" :style="{width: '40vw'}">
+            <PDFUploadForm
+                v-if="pdfUploadDialogVisible"
+                :invoice="currentInvoice"
+                @save="savePDFUpload"
+                @cancel="pdfUploadDialogVisible = false"
+            />
+        </Dialog>
+    </div>
+</template>
+
+<script setup>
+import { ref, computed } from 'vue'
+import { useRouter } from 'vue-router'
+import { useAuthStore } from '@/stores/auth'
+import CrudDataTable from '@/components/CrudDataTable.vue'
+import Column from 'primevue/column'
+import Button from 'primevue/button'
+import Dialog from 'primevue/dialog'
+import Tag from 'primevue/tag'
+import InvoiceForm from './InvoiceForm.vue'
+import PaymentForm from './PaymentForm.vue'
+import PDFUploadForm from './PDFUploadForm.vue'
+
+const router = useRouter()
+const authStore = useAuthStore()
+
+const dialogVisible = ref(false)
+const dialogTitle = ref('')
+const currentInvoice = ref(null)
+const paymentDialogVisible = ref(false)
+const pdfUploadDialogVisible = ref(false)
+
+const canCreate = computed(() => authStore.hasPermission('billing', 'create'))
+
+const columns = [
+    { field: 'invoiceNumber', header: 'Rechnungsnummer' },
+    { field: 'contact.name', header: 'Kunde' },
+    { field: 'invoiceDate', header: 'Rechnungsdatum' },
+    { field: 'dueDate', header: 'Fälligkeitsdatum' },
+    { field: 'total', header: 'Gesamtbetrag' },
+    { field: 'openAmount', header: 'Offen' },
+    { field: 'status', header: 'Status' }
+]
+
+const openCreateDialog = () => {
+    currentInvoice.value = null
+    dialogTitle.value = 'Neue Rechnung'
+    dialogVisible.value = true
+}
+
+const openEditDialog = (invoice) => {
+    currentInvoice.value = invoice
+    dialogTitle.value = 'Rechnung bearbeiten'
+    dialogVisible.value = true
+}
+
+const closeDialog = () => {
+    dialogVisible.value = false
+    currentInvoice.value = null
+}
+
+const saveInvoice = async (invoice) => {
+    // Save logic handled by InvoiceForm
+    closeDialog()
+    // Refresh table
+    window.location.reload()
+}
+
+const deleteInvoice = async (invoice) => {
+    if (confirm(`Rechnung ${invoice.invoiceNumber} wirklich löschen?`)) {
+        await fetch(`/api/invoices/${invoice.id}`, {
+            method: 'DELETE',
+            headers: {
+                'Content-Type': 'application/json'
+            }
+        })
+        window.location.reload()
+    }
+}
+
+const addPayment = (invoice) => {
+    currentInvoice.value = invoice
+    paymentDialogVisible.value = true
+}
+
+const savePayment = async () => {
+    paymentDialogVisible.value = false
+    window.location.reload()
+}
+
+const uploadPDF = (invoice) => {
+    currentInvoice.value = invoice
+    pdfUploadDialogVisible.value = true
+}
+
+const savePDFUpload = async () => {
+    pdfUploadDialogVisible.value = false
+    window.location.reload()
+}
+
+const viewPDF = (invoice) => {
+    window.open(invoice.pdfPath, '_blank')
+}
+
+const formatDate = (dateString) => {
+    if (!dateString) return '-'
+    const date = new Date(dateString)
+    return date.toLocaleDateString('de-DE')
+}
+
+const formatCurrency = (amount) => {
+    if (!amount) return '0,00 €'
+    return new Intl.NumberFormat('de-DE', {
+        style: 'currency',
+        currency: 'EUR'
+    }).format(parseFloat(amount))
+}
+
+const getStatusLabel = (status) => {
+    const labels = {
+        draft: 'Entwurf',
+        open: 'Offen',
+        paid: 'Bezahlt',
+        partial: 'Teilweise bezahlt',
+        overdue: 'Überfällig',
+        cancelled: 'Storniert'
+    }
+    return labels[status] || status
+}
+
+const getStatusSeverity = (status) => {
+    const severities = {
+        draft: 'secondary',
+        open: 'info',
+        paid: 'success',
+        partial: 'warning',
+        overdue: 'danger',
+        cancelled: 'secondary'
+    }
+    return severities[status] || 'info'
+}
+</script>
+
+<style scoped>
+.text-primary {
+    color: var(--primary-color);
+    text-decoration: none;
+    font-weight: 600;
+}
+
+.text-primary:hover {
+    text-decoration: underline;
+}
+</style>
diff --git a/assets/js/views/PDFUploadForm.vue b/assets/js/views/PDFUploadForm.vue
new file mode 100644
index 0000000..cdfe327
--- /dev/null
+++ b/assets/js/views/PDFUploadForm.vue
@@ -0,0 +1,102 @@
+<template>
+    <div class="pdf-upload-form">
+        <Message severity="info">
+            PDF-Upload Funktionalität (Phase 1 MVP - wird in späteren Phasen implementiert)
+        </Message>
+
+        <div class="grid p-fluid mt-3">
+            <div class="col-12">
+                <p>
+                    <strong>Rechnung:</strong> {{ invoice?.invoiceNumber }}
+                </p>
+            </div>
+
+            <!-- File Upload -->
+            <div class="col-12">
+                <label for="pdfFile">PDF-Datei hochladen</label>
+                <input
+                    id="pdfFile"
+                    type="file"
+                    accept="application/pdf"
+                    @change="handleFileChange"
+                    class="p-inputtext p-component"
+                />
+                <small class="text-muted">Nur PDF-Dateien erlaubt (max. 10 MB)</small>
+            </div>
+
+            <div class="col-12" v-if="selectedFile">
+                <Message severity="success">
+                    Datei ausgewählt: {{ selectedFile.name }} ({{ formatFileSize(selectedFile.size) }})
+                </Message>
+            </div>
+        </div>
+
+        <!-- Actions -->
+        <div class="flex gap-2 mt-4">
+            <Button label="Hochladen" icon="pi pi-upload" @click="upload" :disabled="!selectedFile" />
+            <Button label="Abbrechen" icon="pi pi-times" severity="secondary" text @click="cancel" />
+        </div>
+    </div>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+import Button from 'primevue/button'
+import Message from 'primevue/message'
+
+const props = defineProps({
+    invoice: Object
+})
+
+const emit = defineEmits(['save', 'cancel'])
+
+const selectedFile = ref(null)
+
+const handleFileChange = (event) => {
+    const file = event.target.files[0]
+    if (file && file.type === 'application/pdf') {
+        selectedFile.value = file
+    } else {
+        alert('Bitte wählen Sie eine PDF-Datei aus.')
+        event.target.value = ''
+    }
+}
+
+const formatFileSize = (bytes) => {
+    if (bytes < 1024) return bytes + ' B'
+    if (bytes < 1024 * 1024) return (bytes / 1024).toFixed(2) + ' KB'
+    return (bytes / (1024 * 1024)).toFixed(2) + ' MB'
+}
+
+const upload = async () => {
+    if (!selectedFile.value) return
+
+    const formData = new FormData()
+    formData.append('pdf', selectedFile.value)
+    formData.append('invoiceId', props.invoice.id)
+
+    // TODO: Implement upload endpoint
+    // await fetch('/api/invoices/upload-pdf', {
+    //     method: 'POST',
+    //     body: formData
+    // })
+
+    alert('PDF-Upload wird in Phase 2 implementiert. Für Phase 1 MVP können Sie den Pfad manuell in der Datenbank setzen.')
+
+    emit('save')
+}
+
+const cancel = () => {
+    emit('cancel')
+}
+</script>
+
+<style scoped>
+.pdf-upload-form {
+    padding: 1rem;
+}
+
+.text-muted {
+    color: var(--text-color-secondary);
+}
+</style>
diff --git a/assets/js/views/PaymentForm.vue b/assets/js/views/PaymentForm.vue
new file mode 100644
index 0000000..446d697
--- /dev/null
+++ b/assets/js/views/PaymentForm.vue
@@ -0,0 +1,121 @@
+<template>
+    <div class="payment-form">
+        <div class="grid p-fluid">
+            <div class="col-12">
+                <p>
+                    <strong>Rechnung:</strong> {{ invoice?.invoiceNumber }}<br />
+                    <strong>Offener Betrag:</strong> {{ formatCurrency(invoice?.openAmount) }}
+                </p>
+            </div>
+
+            <!-- Zahlungsdatum -->
+            <div class="col-12">
+                <label for="paymentDate">Zahlungsdatum *</label>
+                <Calendar id="paymentDate" v-model="form.paymentDate" date-format="dd.mm.yy" />
+            </div>
+
+            <!-- Betrag -->
+            <div class="col-12">
+                <label for="amount">Betrag *</label>
+                <InputNumber
+                    id="amount"
+                    v-model="form.amount"
+                    mode="currency"
+                    currency="EUR"
+                    locale="de-DE"
+                />
+            </div>
+
+            <!-- Zahlungsart -->
+            <div class="col-12">
+                <label for="paymentMethod">Zahlungsart</label>
+                <Dropdown
+                    id="paymentMethod"
+                    v-model="form.paymentMethod"
+                    :options="paymentMethods"
+                    option-label="label"
+                    option-value="value"
+                />
+            </div>
+
+            <!-- Notizen -->
+            <div class="col-12">
+                <label for="notes">Notizen</label>
+                <Textarea id="notes" v-model="form.notes" rows="3" />
+            </div>
+        </div>
+
+        <!-- Actions -->
+        <div class="flex gap-2 mt-4">
+            <Button label="Speichern" icon="pi pi-check" @click="save" />
+            <Button label="Abbrechen" icon="pi pi-times" severity="secondary" text @click="cancel" />
+        </div>
+    </div>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+import InputNumber from 'primevue/inputnumber'
+import Calendar from 'primevue/calendar'
+import Dropdown from 'primevue/dropdown'
+import Textarea from 'primevue/textarea'
+import Button from 'primevue/button'
+
+const props = defineProps({
+    invoice: Object
+})
+
+const emit = defineEmits(['save', 'cancel'])
+
+const form = ref({
+    paymentDate: new Date(),
+    amount: parseFloat(props.invoice?.openAmount || 0),
+    paymentMethod: 'bank_transfer',
+    notes: ''
+})
+
+const paymentMethods = [
+    { label: 'Überweisung', value: 'bank_transfer' },
+    { label: 'Bar', value: 'cash' },
+    { label: 'Karte', value: 'card' },
+    { label: 'PayPal', value: 'paypal' },
+    { label: 'SEPA-Lastschrift', value: 'sepa' },
+    { label: 'Sonstiges', value: 'other' }
+]
+
+const formatCurrency = (amount) => {
+    if (!amount) return '0,00 €'
+    return new Intl.NumberFormat('de-DE', {
+        style: 'currency',
+        currency: 'EUR'
+    }).format(parseFloat(amount))
+}
+
+const save = async () => {
+    const payload = {
+        invoice: `/api/invoices/${props.invoice.id}`,
+        paymentDate: form.value.paymentDate.toISOString().split('T')[0],
+        amount: form.value.amount.toString(),
+        paymentMethod: form.value.paymentMethod,
+        notes: form.value.notes
+    }
+
+    await fetch('/api/payments', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify(payload)
+    })
+
+    emit('save')
+}
+
+const cancel = () => {
+    emit('cancel')
+}
+</script>
+
+<style scoped>
+.payment-form {
+    padding: 1rem;
+}
+</style>
diff --git a/composer.json b/composer.json
index 331069e..89a3603 100644
--- a/composer.json
+++ b/composer.json
@@ -15,6 +15,7 @@
         "doctrine/orm": "^3.5",
         "knpuniversity/oauth2-client-bundle": "*",
         "league/oauth2-client": "*",
+        "mycrm/billing-module": "@dev",
         "mycrm/test-module": "*",
         "nelmio/cors-bundle": "^2.6",
         "phpdocumentor/reflection-docblock": "^5.6",
@@ -118,6 +119,10 @@
         "mycrm-test-module": {
             "type": "vcs",
             "url": "https://git.osdata-home.de/mycrm/mycrm-test-module"
+        },
+        "mycrm-billing-module": {
+            "type": "path",
+            "url": "../mycrm-billing-module"
         }
     }
 }
diff --git a/composer.lock b/composer.lock
index 96afb53..60f4496 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "caa943b57e0e058e754382b31531775b",
+    "content-hash": "04f5bf6ec79dae707473e4ea7e9892b4",
     "packages": [
         {
             "name": "api-platform/core",
@@ -2038,6 +2038,39 @@
             ],
             "time": "2025-03-24T10:02:05+00:00"
         },
+        {
+            "name": "mycrm/billing-module",
+            "version": "dev-main",
+            "dist": {
+                "type": "path",
+                "url": "../mycrm-billing-module",
+                "reference": "3fc81714629410d172800eec9b1c58b3d40568ff"
+            },
+            "require": {
+                "api-platform/core": "^4.0",
+                "doctrine/orm": "^3.0",
+                "php": ">=8.2",
+                "symfony/framework-bundle": "^7.1"
+            },
+            "type": "symfony-bundle",
+            "extra": {
+                "symfony": {
+                    "require": "7.1.*"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "MyCRM\\BillingModule\\": "src/"
+                }
+            },
+            "license": [
+                "proprietary"
+            ],
+            "description": "Ausgangsrechnungsverwaltung für myCRM",
+            "transport-options": {
+                "relative": true
+            }
+        },
         {
             "name": "mycrm/test-module",
             "version": "v1.0.1",
@@ -11047,7 +11080,9 @@
     ],
     "aliases": [],
     "minimum-stability": "stable",
-    "stability-flags": [],
+    "stability-flags": {
+        "mycrm/billing-module": 20
+    },
     "prefer-stable": true,
     "prefer-lowest": false,
     "platform": {
diff --git a/config/bundles.php b/config/bundles.php
index d6b4866..72f5e4a 100644
--- a/config/bundles.php
+++ b/config/bundles.php
@@ -19,4 +19,5 @@ return [
     Doctrine\Bundle\FixturesBundle\DoctrineFixturesBundle::class => ['dev' => true, 'test' => true],
     KnpU\OAuth2ClientBundle\KnpUOAuth2ClientBundle::class => ['all' => true],
     MyCRM\TestModule\TestModuleBundle::class => ['all' => true],
+    MyCRM\BillingModule\BillingModuleBundle::class => ['all' => true],
 ];
diff --git a/docs/PLUGIN_MENUS_AND_PERMISSIONS.md b/docs/PLUGIN_MENUS_AND_PERMISSIONS.md
new file mode 100644
index 0000000..3a2e177
--- /dev/null
+++ b/docs/PLUGIN_MENUS_AND_PERMISSIONS.md
@@ -0,0 +1,521 @@
+# Plugin-Menüs und Permissions
+
+Anleitung zur dynamischen Registrierung von Menü-Items und Permissions durch Plugins.
+
+## Übersicht
+
+Das Plugin-System unterstützt jetzt:
+
+✅ **Dynamische Menü-Items** - Plugins können eigene Menüpunkte hinzufügen
+✅ **Automatische Permission-Synchronisation** - Modul-Permissions werden automatisch in der DB angelegt
+✅ **Permission-basierte Sichtbarkeit** - Menüpunkte erscheinen nur für berechtigte User
+✅ **Gruppierung** - Plugin-Menüs können gruppiert werden
+
+---
+
+## 1. Menü-Items im Plugin definieren
+
+### In deiner Plugin-Klasse:
+
+```php
+public function getMenuItems(): array
+{
+    return [
+        [
+            'label' => 'Rechnungen',         // Menü-Titel
+            'icon' => 'pi-file-pdf',         // PrimeIcons Icon (ohne pi pi-fw prefix)
+            'group' => 'Finanzen',           // Gruppierung im Menü
+            'items' => [
+                [
+                    'label' => 'Alle Rechnungen',
+                    'icon' => 'pi-list',
+                    'to' => '/billing/invoices',           // Vue Router path
+                    'permission' => 'billing.view'         // Optional: Permission-Check
+                ],
+                [
+                    'label' => 'Neue Rechnung',
+                    'icon' => 'pi-plus',
+                    'to' => '/billing/invoices/create',
+                    'permission' => 'billing.create'
+                ],
+                [
+                    'separator' => true                     // Optional: Trennlinie
+                ],
+                [
+                    'label' => 'Einstellungen',
+                    'icon' => 'pi-cog',
+                    'to' => '/billing/settings',
+                    'permission' => 'billing.manage'
+                ]
+            ]
+        ]
+    ];
+}
+```
+
+### Menü-Item Optionen:
+
+| Feld | Typ | Required | Beschreibung |
+|------|-----|----------|--------------|
+| `label` | string | ✅ | Anzeigename des Menüpunkts |
+| `icon` | string | ❌ | PrimeIcons Icon (ohne `pi pi-fw` prefix) |
+| `to` | string | ❌ | Vue Router path |
+| `url` | string | ❌ | Externe URL (alternativ zu `to`) |
+| `items` | array | ❌ | Sub-Menüpunkte |
+| `permission` | string | ❌ | Permission-String für Sichtbarkeits-Check |
+| `group` | string | ❌ | Gruppierung im Hauptmenü |
+| `separator` | bool | ❌ | Trennlinie (nur in Sub-Items) |
+
+---
+
+## 2. Permissions definieren
+
+### In deiner Plugin-Klasse:
+
+```php
+public function getPermissionModules(): array
+{
+    return ['billing', 'invoicing'];
+}
+```
+
+Das System erstellt automatisch folgende Permissions:
+- `billing.view`
+- `billing.create`
+- `billing.edit`
+- `billing.delete`
+- `billing.export`
+- `billing.manage`
+
+### Permission-Synchronisation durchführen:
+
+```bash
+# Alle Plugins synchronisieren
+php bin/console app:plugin:sync-permissions
+
+# Nur ein bestimmtes Plugin
+php bin/console app:plugin:sync-permissions billing
+
+# Dry-Run (zeigt nur was passieren würde)
+php bin/console app:plugin:sync-permissions --dry-run
+```
+
+**Output:**
+```
+Plugin Permission-Module Synchronisation
+========================================
+
+Synchronisiere alle Plugins...
+------------------------------
+
+ Aktion         Anzahl
+ Neu erstellt   2
+ Aktualisiert   0
+ Übersprungen   5
+```
+
+---
+
+## 3. Frontend Integration
+
+### API-Endpoints:
+
+#### GET /api/plugin-menu
+Gibt alle Plugin-Menü-Items als flache Liste zurück.
+
+**Response:**
+```json
+{
+    "success": true,
+    "data": [
+        {
+            "label": "Alle Rechnungen",
+            "icon": "pi-list",
+            "to": "/billing/invoices",
+            "permission": "billing.view",
+            "source": "billing"
+        }
+    ],
+    "count": 1
+}
+```
+
+#### GET /api/plugin-menu/grouped
+Gibt gruppierte Plugin-Menü-Items zurück.
+
+**Response:**
+```json
+{
+    "success": true,
+    "data": {
+        "Finanzen": [
+            {
+                "label": "Rechnungen",
+                "icon": "pi-file-pdf",
+                "items": [...]
+            }
+        ]
+    },
+    "groups": ["Finanzen"]
+}
+```
+
+### AppMenu.vue
+
+Das Menü lädt automatisch Plugin-Menüs beim Mount:
+
+```vue
+<script setup>
+import { ref, onMounted } from 'vue';
+
+const model = ref([...coreMenu]);
+
+const loadPluginMenus = async () => {
+    const response = await fetch('/api/plugin-menu/grouped');
+    const data = await response.json();
+
+    // Plugin-Menüs werden automatisch hinzugefügt
+    // Permission-Checks werden automatisch durchgeführt
+};
+
+onMounted(() => {
+    loadPluginMenus();
+});
+</script>
+```
+
+---
+
+## 4. Permission-Checks im Frontend
+
+### Mit Composition API:
+
+```vue
+<script setup>
+import { useAuthStore } from '@/stores/auth';
+
+const authStore = useAuthStore();
+
+// Permission prüfen
+const canViewInvoices = authStore.hasPermission('billing.view');
+</script>
+
+<template>
+    <Button v-if="canViewInvoices" label="Rechnung anzeigen" />
+</template>
+```
+
+### Im Template:
+
+```vue
+<template>
+    <div v-if="authStore.hasPermission('billing.create')">
+        <Button label="Neue Rechnung" @click="createInvoice" />
+    </div>
+</template>
+```
+
+---
+
+## 5. Beispiel: Vollständiges Plugin
+
+### BillingModulePlugin.php
+
+```php
+<?php
+
+namespace MyCRM\BillingModule;
+
+use App\Plugin\LicenseValidatorInterface;
+use App\Plugin\ModulePluginInterface;
+
+class BillingModulePlugin implements ModulePluginInterface
+{
+    public function __construct(
+        private readonly LicenseValidatorInterface $licenseValidator
+    ) {}
+
+    public function getIdentifier(): string
+    {
+        return 'billing';
+    }
+
+    public function getDisplayName(): string
+    {
+        return 'Rechnungsmodul';
+    }
+
+    public function getVersion(): string
+    {
+        return '1.0.0';
+    }
+
+    public function getDescription(): string
+    {
+        return 'Verwaltung von Rechnungen, Angeboten und Zahlungen';
+    }
+
+    public function isLicensed(): bool
+    {
+        return $this->licenseValidator->validate('billing')['valid'];
+    }
+
+    public function getLicenseInfo(): array
+    {
+        return $this->licenseValidator->validate('billing');
+    }
+
+    public function boot(): void
+    {
+        if (!$this->isLicensed()) {
+            throw new \RuntimeException('Billing Module nicht lizenziert');
+        }
+
+        // Services, Routes, etc. registrieren
+    }
+
+    public function getPermissionModules(): array
+    {
+        return ['billing', 'invoicing', 'payments'];
+    }
+
+    public function getMenuItems(): array
+    {
+        return [
+            [
+                'label' => 'Rechnungen',
+                'icon' => 'pi-file-pdf',
+                'group' => 'Finanzen',
+                'items' => [
+                    [
+                        'label' => 'Dashboard',
+                        'icon' => 'pi-chart-line',
+                        'to' => '/billing/dashboard',
+                        'permission' => 'billing.view'
+                    ],
+                    [
+                        'label' => 'Alle Rechnungen',
+                        'icon' => 'pi-list',
+                        'to' => '/billing/invoices',
+                        'permission' => 'billing.view'
+                    ],
+                    [
+                        'label' => 'Neue Rechnung',
+                        'icon' => 'pi-plus',
+                        'to' => '/billing/invoices/create',
+                        'permission' => 'billing.create'
+                    ],
+                    [
+                        'separator' => true
+                    ],
+                    [
+                        'label' => 'Zahlungen',
+                        'icon' => 'pi-money-bill',
+                        'to' => '/billing/payments',
+                        'permission' => 'payments.view'
+                    ],
+                    [
+                        'label' => 'Einstellungen',
+                        'icon' => 'pi-cog',
+                        'to' => '/billing/settings',
+                        'permission' => 'billing.manage'
+                    ]
+                ]
+            ]
+        ];
+    }
+
+    public function canInstall(): array
+    {
+        $errors = [];
+
+        if (PHP_VERSION_ID < 80200) {
+            $errors[] = 'PHP 8.2+ erforderlich';
+        }
+
+        return [
+            'success' => empty($errors),
+            'errors' => $errors
+        ];
+    }
+}
+```
+
+---
+
+## 6. Workflow: Neues Plugin mit Menüs
+
+### Schritt 1: Plugin erstellen
+
+```bash
+cd ../mycrm-billing-module
+composer init
+# Name: mycrm/billing-module
+```
+
+### Schritt 2: Plugin-Klasse implementieren
+
+Siehe Beispiel oben - implementiere `getMenuItems()` und `getPermissionModules()`.
+
+### Schritt 3: In myCRM installieren
+
+```bash
+cd ../myCRM
+composer config repositories.mycrm-billing-module path ../mycrm-billing-module
+composer require mycrm/billing-module:@dev
+```
+
+### Schritt 4: Permissions synchronisieren
+
+```bash
+php bin/console app:plugin:sync-permissions billing
+```
+
+**Output:**
+```
+Neu erstellt: 3 (billing, invoicing, payments)
+```
+
+### Schritt 5: Cache leeren
+
+```bash
+php bin/console cache:clear
+```
+
+### Schritt 6: Lizenz aktivieren
+
+```bash
+php bin/console app:module:license billing YOUR_GITEA_TOKEN
+```
+
+### Schritt 7: Testen
+
+1. Frontend öffnen
+2. Plugin-Menü erscheint unter "Finanzen"
+3. Menüpunkte sind nur sichtbar mit Berechtigung
+
+---
+
+## 7. Debugging
+
+### Menü-Items überprüfen:
+
+```bash
+curl http://localhost:8000/api/plugin-menu | jq
+```
+
+### Permissions in DB überprüfen:
+
+```sql
+SELECT * FROM modules WHERE code IN ('billing', 'invoicing', 'payments');
+```
+
+### Plugin-Status:
+
+```bash
+php bin/console app:module:list
+```
+
+### Logs:
+
+```bash
+tail -f var/log/dev.log | grep -E "(Plugin|Menu|Permission)"
+```
+
+---
+
+## 8. Best Practices
+
+### ✅ DO's:
+
+- **Gruppiere verwandte Menüs** - Nutze `group` für bessere Organisation
+- **Permission-Checks** - Definiere `permission` für alle sensiblen Menüpunkte
+- **Icons verwenden** - Macht das Menü übersichtlicher
+- **Synchronisiere nach Installation** - `app:plugin:sync-permissions` nach jedem Plugin-Update
+
+### ❌ DON'Ts:
+
+- **Keine Core-Gruppen überschreiben** - "Home", "CRM", "Administration" sind reserviert
+- **Keine tiefen Verschachtelungen** - Max. 2 Ebenen (Gruppe → Items)
+- **Keine externen URLs ohne Warnung** - User erwarten interne Navigation
+
+---
+
+## 9. Troubleshooting
+
+### Problem: Menü erscheint nicht
+
+**Lösung:**
+```bash
+# Cache leeren
+php bin/console cache:clear
+
+# Plugin-Status prüfen
+php bin/console app:module:list
+
+# API testen
+curl http://localhost:8000/api/plugin-menu/grouped
+
+# Browser-Console überprüfen
+```
+
+### Problem: Permissions fehlen
+
+**Lösung:**
+```bash
+# Permissions synchronisieren
+php bin/console app:plugin:sync-permissions
+
+# DB überprüfen
+SELECT * FROM modules WHERE code = 'billing';
+
+# Rolle zuweisen
+# In der Rollenverwaltung das neue Modul auswählen
+```
+
+### Problem: Permission-Checks funktionieren nicht
+
+**Lösung:**
+- Prüfe ob User die Rolle hat
+- Prüfe ob Rolle die Permission hat
+- Prüfe `authStore.hasPermission()` Implementierung
+
+---
+
+## 10. Migration bestehender Plugins
+
+Wenn du bereits Plugins hast, füge einfach `getMenuItems()` hinzu:
+
+```php
+// Altes Plugin
+class MyPlugin implements ModulePluginInterface {
+    // ... bestehende Methoden ...
+}
+
+// Neu: Füge hinzu
+class MyPlugin implements ModulePluginInterface {
+    // ... bestehende Methoden ...
+
+    public function getMenuItems(): array
+    {
+        return [
+            // Deine Menüs hier
+        ];
+    }
+}
+```
+
+Dann:
+```bash
+composer dump-autoload
+php bin/console cache:clear
+```
+
+---
+
+## Support
+
+Bei Fragen siehe:
+- `PLUGIN_SYSTEM.md` - Allgemeine Plugin-Architektur
+- `GITEA_LICENSE_SYSTEM.md` - Lizenzierung
+- `docs/PERMISSIONS.md` - Permission-System
diff --git a/migrations/Version20251205095156.php b/migrations/Version20251205095156.php
new file mode 100644
index 0000000..1aa89d0
--- /dev/null
+++ b/migrations/Version20251205095156.php
@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Auto-generated Migration: Please modify to your needs!
+ */
+final class Version20251205095156 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return '';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // this up() migration is auto-generated, please modify it to your needs
+        $this->addSql('CREATE TABLE invoice_items (id INT AUTO_INCREMENT NOT NULL, invoice_id INT NOT NULL, description LONGTEXT NOT NULL, quantity NUMERIC(10, 2) NOT NULL, unit_price NUMERIC(10, 2) NOT NULL, tax_rate NUMERIC(5, 2) NOT NULL, subtotal NUMERIC(10, 2) NOT NULL, tax_amount NUMERIC(10, 2) NOT NULL, total NUMERIC(10, 2) NOT NULL, INDEX IDX_DCC4B9F82989F1FD (invoice_id), PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB');
+        $this->addSql('CREATE TABLE invoices (id INT AUTO_INCREMENT NOT NULL, contact_id INT NOT NULL, invoice_number VARCHAR(50) NOT NULL, status VARCHAR(20) NOT NULL, invoice_date DATE NOT NULL, due_date DATE NOT NULL, subtotal NUMERIC(10, 2) NOT NULL, tax_total NUMERIC(10, 2) NOT NULL, total NUMERIC(10, 2) NOT NULL, paid_amount NUMERIC(10, 2) NOT NULL, pdf_path VARCHAR(255) DEFAULT NULL, notes LONGTEXT DEFAULT NULL, created_at DATETIME NOT NULL, updated_at DATETIME NOT NULL, UNIQUE INDEX UNIQ_6A2F2F952DA68207 (invoice_number), INDEX IDX_6A2F2F95E7A1254A (contact_id), PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB');
+        $this->addSql('CREATE TABLE payments (id INT AUTO_INCREMENT NOT NULL, invoice_id INT NOT NULL, payment_date DATE NOT NULL, amount NUMERIC(10, 2) NOT NULL, payment_method VARCHAR(50) NOT NULL, notes LONGTEXT DEFAULT NULL, created_at DATETIME NOT NULL, INDEX IDX_65D29B322989F1FD (invoice_id), PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB');
+        $this->addSql('ALTER TABLE invoice_items ADD CONSTRAINT FK_DCC4B9F82989F1FD FOREIGN KEY (invoice_id) REFERENCES invoices (id)');
+        $this->addSql('ALTER TABLE invoices ADD CONSTRAINT FK_6A2F2F95E7A1254A FOREIGN KEY (contact_id) REFERENCES contacts (id)');
+        $this->addSql('ALTER TABLE payments ADD CONSTRAINT FK_65D29B322989F1FD FOREIGN KEY (invoice_id) REFERENCES invoices (id)');
+    }
+
+    public function down(Schema $schema): void
+    {
+        // this down() migration is auto-generated, please modify it to your needs
+        $this->addSql('ALTER TABLE invoice_items DROP FOREIGN KEY FK_DCC4B9F82989F1FD');
+        $this->addSql('ALTER TABLE invoices DROP FOREIGN KEY FK_6A2F2F95E7A1254A');
+        $this->addSql('ALTER TABLE payments DROP FOREIGN KEY FK_65D29B322989F1FD');
+        $this->addSql('DROP TABLE invoice_items');
+        $this->addSql('DROP TABLE invoices');
+        $this->addSql('DROP TABLE payments');
+    }
+}
diff --git a/src/Command/SyncPluginPermissionsCommand.php b/src/Command/SyncPluginPermissionsCommand.php
new file mode 100644
index 0000000..ce3bf60
--- /dev/null
+++ b/src/Command/SyncPluginPermissionsCommand.php
@@ -0,0 +1,135 @@
+<?php
+
+namespace App\Command;
+
+use App\Service\PermissionModuleSync;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+/**
+ * Command zur Synchronisation von Plugin-Permissions
+ */
+#[AsCommand(
+    name: 'app:plugin:sync-permissions',
+    description: 'Synchronisiert Plugin-Permission-Module mit der Datenbank',
+)]
+class SyncPluginPermissionsCommand extends Command
+{
+    public function __construct(
+        private readonly PermissionModuleSync $permissionSync
+    ) {
+        parent::__construct();
+    }
+
+    protected function configure(): void
+    {
+        $this
+            ->addArgument('plugin', InputArgument::OPTIONAL, 'Plugin-Identifier (optional - sync alle wenn leer)')
+            ->addOption('dry-run', null, InputOption::VALUE_NONE, 'Zeigt Änderungen an ohne sie durchzuführen')
+            ->addOption('force', 'f', InputOption::VALUE_NONE, 'Synchronisiert auch unlizenzierte Module (für Development)')
+            ->setHelp(<<<'HELP'
+Synchronisiert die Permission-Module von Plugins mit der Datenbank.
+
+Für jedes lizenzierte Plugin werden die von getPermissionModules() zurückgegebenen
+Module automatisch in der Module-Tabelle angelegt, falls sie noch nicht existieren.
+
+Beispiele:
+  # Alle Plugins synchronisieren
+  php bin/console app:plugin:sync-permissions
+
+  # Nur ein bestimmtes Plugin
+  php bin/console app:plugin:sync-permissions test
+
+  # Dry-Run (zeigt nur was passieren würde)
+  php bin/console app:plugin:sync-permissions --dry-run
+
+Nach der Synchronisation:
+  - Neue Module sind verfügbar im Permission-System
+  - Admins können Permissions für diese Module zuweisen
+  - Module erscheinen in der Rollenverwaltung
+HELP
+            );
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $io = new SymfonyStyle($input, $output);
+        $pluginId = $input->getArgument('plugin');
+        $dryRun = $input->getOption('dry-run');
+        $force = $input->getOption('force');
+
+        if ($dryRun) {
+            $io->warning('DRY-RUN Modus - Keine Änderungen werden gespeichert!');
+        }
+
+        if ($force) {
+            $io->note('FORCE Modus - Auch unlizenzierte Module werden synchronisiert!');
+        }
+
+        $io->title('Plugin Permission-Module Synchronisation');
+
+        if ($pluginId) {
+            $io->section(sprintf('Synchronisiere Plugin: %s', $pluginId));
+
+            try {
+                $stats = $this->permissionSync->syncPlugin($pluginId, $force);
+                $this->displayStats($io, $stats);
+
+                $io->success(sprintf('Plugin "%s" erfolgreich synchronisiert!', $pluginId));
+                return Command::SUCCESS;
+
+            } catch (\Throwable $e) {
+                $io->error(sprintf('Fehler: %s', $e->getMessage()));
+                return Command::FAILURE;
+            }
+        }
+
+        // Alle Plugins synchronisieren
+        $io->section('Synchronisiere alle Plugins...');
+
+        $stats = $this->permissionSync->syncAll($force);
+
+        $this->displayStats($io, $stats);
+
+        if (!empty($stats['errors'])) {
+            $io->warning('Es gab Fehler bei folgenden Plugins:');
+            $io->listing($stats['errors']);
+        }
+
+        if ($stats['created'] === 0 && $stats['updated'] === 0) {
+            $io->info('Keine Änderungen notwendig - alle Module sind bereits synchron.');
+            return Command::SUCCESS;
+        }
+
+        $io->success('Synchronisation abgeschlossen!');
+
+        $io->section('Nächste Schritte');
+        $io->listing([
+            'Rollenverwaltung: Neue Module erscheinen in den Permissions',
+            'Benutzerverwaltung: Admins können jetzt Permissions zuweisen',
+            'Cache leeren (falls nötig): php bin/console cache:clear',
+        ]);
+
+        return Command::SUCCESS;
+    }
+
+    private function displayStats(SymfonyStyle $io, array $stats): void
+    {
+        $rows = [
+            ['Neu erstellt', $stats['created']],
+            ['Aktualisiert', $stats['updated']],
+            ['Übersprungen', $stats['skipped']],
+        ];
+
+        if (isset($stats['errors']) && !empty($stats['errors'])) {
+            $rows[] = ['Fehler', count($stats['errors'])];
+        }
+
+        $io->table(['Aktion', 'Anzahl'], $rows);
+    }
+}
diff --git a/src/Controller/Api/PluginMenuController.php b/src/Controller/Api/PluginMenuController.php
new file mode 100644
index 0000000..4591688
--- /dev/null
+++ b/src/Controller/Api/PluginMenuController.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace App\Controller\Api;
+
+use App\Service\MenuItemRegistry;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\JsonResponse;
+use Symfony\Component\Routing\Annotation\Route;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+/**
+ * API-Endpoint für Plugin-Menü-Items
+ */
+#[Route('/api/plugin-menu', name: 'api_plugin_menu_')]
+#[IsGranted('ROLE_USER')]
+class PluginMenuController extends AbstractController
+{
+    public function __construct(
+        private readonly MenuItemRegistry $menuRegistry
+    ) {
+    }
+
+    /**
+     * Gibt alle Plugin-Menü-Items zurück
+     *
+     * GET /api/plugin-menu
+     */
+    #[Route('', name: 'get_all', methods: ['GET'])]
+    public function getAll(): JsonResponse
+    {
+        $menuItems = $this->menuRegistry->getFlatMenuItems();
+
+        return $this->json([
+            'success' => true,
+            'data' => $menuItems,
+            'count' => count($menuItems),
+        ]);
+    }
+
+    /**
+     * Gibt gruppierte Plugin-Menü-Items zurück
+     *
+     * GET /api/plugin-menu/grouped
+     */
+    #[Route('/grouped', name: 'get_grouped', methods: ['GET'])]
+    public function getGrouped(): JsonResponse
+    {
+        $grouped = $this->menuRegistry->getGroupedMenuItems();
+
+        return $this->json([
+            'success' => true,
+            'data' => $grouped,
+            'groups' => array_keys($grouped),
+        ]);
+    }
+}
diff --git a/src/Plugin/ModulePluginInterface.php b/src/Plugin/ModulePluginInterface.php
index 18781b3..72f927e 100644
--- a/src/Plugin/ModulePluginInterface.php
+++ b/src/Plugin/ModulePluginInterface.php
@@ -74,4 +74,29 @@ interface ModulePluginInterface
      * @return array{success: bool, errors: array<string>}
      */
     public function canInstall(): array;
+
+    /**
+     * Gibt Menü-Items zurück, die in der Haupt-Navigation angezeigt werden sollen
+     *
+     * @return array<array{
+     *   label: string,
+     *   icon?: string,
+     *   to?: string,
+     *   url?: string,
+     *   items?: array,
+     *   permission?: string,
+     *   separator?: bool
+     * }>
+     *
+     * Beispiel:
+     * [
+     *   'label' => 'Rechnungen',
+     *   'icon' => 'pi pi-fw pi-file',
+     *   'items' => [
+     *     ['label' => 'Alle Rechnungen', 'to' => '/billing/invoices', 'permission' => 'billing.view'],
+     *     ['label' => 'Neue Rechnung', 'to' => '/billing/invoices/create', 'permission' => 'billing.create'],
+     *   ]
+     * ]
+     */
+    public function getMenuItems(): array;
 }
diff --git a/src/Service/MenuItemRegistry.php b/src/Service/MenuItemRegistry.php
new file mode 100644
index 0000000..e2000a3
--- /dev/null
+++ b/src/Service/MenuItemRegistry.php
@@ -0,0 +1,119 @@
+<?php
+
+namespace App\Service;
+
+use App\Plugin\ModuleRegistry;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Registry für Plugin-Menü-Items
+ *
+ * Sammelt alle Menü-Items von installierten und lizenzierten Plugins
+ */
+class MenuItemRegistry
+{
+    public function __construct(
+        private readonly ModuleRegistry $moduleRegistry,
+        private readonly LoggerInterface $logger
+    ) {
+    }
+
+    /**
+     * Gibt alle Menü-Items von lizenzierten Plugins zurück
+     *
+     * @return array<array{
+     *   label: string,
+     *   icon?: string,
+     *   to?: string,
+     *   items?: array,
+     *   permission?: string,
+     *   separator?: bool,
+     *   source: string
+     * }>
+     */
+    public function getPluginMenuItems(): array
+    {
+        $menuItems = [];
+
+        foreach ($this->moduleRegistry->getAllModules() as $plugin) {
+            // Nur lizenzierte Module berücksichtigen
+            if (!$plugin->isLicensed()) {
+                $this->logger->debug(sprintf(
+                    'Plugin "%s" übersprungen: Nicht lizenziert',
+                    $plugin->getIdentifier()
+                ));
+                continue;
+            }
+
+            try {
+                $pluginMenuItems = $plugin->getMenuItems();
+
+                foreach ($pluginMenuItems as $item) {
+                    // Source hinzufügen für Debugging
+                    $item['source'] = $plugin->getIdentifier();
+                    $menuItems[] = $item;
+                }
+
+                $this->logger->debug(sprintf(
+                    'Plugin "%s": %d Menü-Items geladen',
+                    $plugin->getIdentifier(),
+                    count($pluginMenuItems)
+                ));
+
+            } catch (\Throwable $e) {
+                $this->logger->error(sprintf(
+                    'Fehler beim Laden der Menü-Items von Plugin "%s": %s',
+                    $plugin->getIdentifier(),
+                    $e->getMessage()
+                ));
+            }
+        }
+
+        return $menuItems;
+    }
+
+    /**
+     * Gibt alle Menü-Items gruppiert nach Kategorien zurück
+     *
+     * @return array<string, array> z.B. ['CRM' => [...], 'Finanzen' => [...]]
+     */
+    public function getGroupedMenuItems(): array
+    {
+        $items = $this->getPluginMenuItems();
+        $grouped = [];
+
+        foreach ($items as $item) {
+            // Wenn Item eine Gruppe hat
+            if (isset($item['group'])) {
+                $group = $item['group'];
+                unset($item['group']);
+
+                if (!isset($grouped[$group])) {
+                    $grouped[$group] = [];
+                }
+
+                $grouped[$group][] = $item;
+            } else {
+                // Fallback: Nach Plugin-Namen gruppieren
+                $pluginId = $item['source'] ?? 'unknown';
+                if (!isset($grouped[$pluginId])) {
+                    $grouped[$pluginId] = [];
+                }
+                $grouped[$pluginId][] = $item;
+            }
+        }
+
+        return $grouped;
+    }
+
+    /**
+     * Gibt Menü-Items als flache Liste zurück
+     * (Nützlich für Frontend ohne Gruppierung)
+     *
+     * @return array
+     */
+    public function getFlatMenuItems(): array
+    {
+        return $this->getPluginMenuItems();
+    }
+}
diff --git a/src/Service/PermissionModuleSync.php b/src/Service/PermissionModuleSync.php
new file mode 100644
index 0000000..9722230
--- /dev/null
+++ b/src/Service/PermissionModuleSync.php
@@ -0,0 +1,187 @@
+<?php
+
+namespace App\Service;
+
+use App\Entity\Module;
+use App\Plugin\ModuleRegistry;
+use App\Repository\ModuleRepository;
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Service zur Synchronisation von Plugin-Permissions mit der Datenbank
+ *
+ * Liest alle Permission-Module von Plugins und legt sie in der DB an,
+ * falls sie noch nicht existieren.
+ */
+class PermissionModuleSync
+{
+    public function __construct(
+        private readonly ModuleRegistry $moduleRegistry,
+        private readonly ModuleRepository $moduleRepository,
+        private readonly EntityManagerInterface $em,
+        private readonly LoggerInterface $logger
+    ) {
+    }
+
+    /**
+     * Synchronisiert alle Plugin-Module mit der Datenbank
+     *
+     * @param bool $force Synchronisiert auch unlizenzierte Module (für Development)
+     * @return array{created: int, updated: int, skipped: int, errors: array<string>}
+     */
+    public function syncAll(bool $force = false): array
+    {
+        $stats = [
+            'created' => 0,
+            'updated' => 0,
+            'skipped' => 0,
+            'errors' => [],
+        ];
+
+        foreach ($this->moduleRegistry->getAllModules() as $plugin) {
+            try {
+                $result = $this->syncPlugin($plugin->getIdentifier(), $force);
+                $stats['created'] += $result['created'];
+                $stats['updated'] += $result['updated'];
+                $stats['skipped'] += $result['skipped'];
+            } catch (\Throwable $e) {
+                $error = sprintf(
+                    'Plugin "%s": %s',
+                    $plugin->getIdentifier(),
+                    $e->getMessage()
+                );
+                $stats['errors'][] = $error;
+                $this->logger->error($error);
+            }
+        }
+
+        return $stats;
+    }
+
+    /**
+     * Synchronisiert die Module eines bestimmten Plugins
+     *
+     * @param string $pluginIdentifier
+     * @param bool $force Synchronisiert auch unlizenzierte Module (für Development)
+     * @return array{created: int, updated: int, skipped: int}
+     */
+    public function syncPlugin(string $pluginIdentifier, bool $force = false): array
+    {
+        $stats = ['created' => 0, 'updated' => 0, 'skipped' => 0];
+
+        $plugin = $this->moduleRegistry->getModule($pluginIdentifier);
+        if (!$plugin) {
+            throw new \RuntimeException(sprintf('Plugin "%s" nicht gefunden', $pluginIdentifier));
+        }
+
+        // Nur lizenzierte Module synchronisieren (außer force)
+        if (!$force && !$plugin->isLicensed()) {
+            $this->logger->info(sprintf(
+                'Plugin "%s" übersprungen: Nicht lizenziert',
+                $pluginIdentifier
+            ));
+            return $stats;
+        }
+
+        $permissionModules = $plugin->getPermissionModules();
+
+        foreach ($permissionModules as $moduleCode) {
+            $result = $this->syncModule(
+                $moduleCode,
+                $plugin->getDisplayName(),
+                $plugin->getDescription()
+            );
+
+            $stats[$result]++;
+        }
+
+        $this->em->flush();
+
+        return $stats;
+    }
+
+    /**
+     * Synchronisiert ein einzelnes Modul
+     *
+     * @param string $code Modul-Code (z.B. 'billing', 'invoicing')
+     * @param string $displayName Display-Name des Plugins
+     * @param string $description Plugin-Beschreibung
+     * @return string 'created', 'updated' oder 'skipped'
+     */
+    private function syncModule(string $code, string $displayName, string $description): string
+    {
+        $existingModule = $this->moduleRepository->findOneBy(['code' => $code]);
+
+        if ($existingModule) {
+            // Modul existiert bereits - Update nur wenn nötig
+            $updated = false;
+
+            if ($existingModule->getDescription() !== $description) {
+                $existingModule->setDescription($description);
+                $updated = true;
+            }
+
+            if ($updated) {
+                $this->logger->info(sprintf('Modul "%s" aktualisiert', $code));
+                return 'updated';
+            }
+
+            return 'skipped';
+        }
+
+        // Neues Modul anlegen
+        $module = new Module();
+        $module->setCode($code);
+        // Name: Plugin-Name + Code (falls unterschiedlich)
+        $moduleName = $displayName;
+        if (strcasecmp($code, $displayName) !== 0) {
+            $moduleName = sprintf('%s (%s)', $displayName, ucfirst($code));
+        }
+        $module->setName($moduleName);
+        $module->setDescription($description);
+        $module->setIsActive(true);
+        $module->setSortOrder($this->getNextSortOrder());
+
+        // Icon aus Code ableiten (optional)
+        $icon = $this->guessIcon($code);
+        if ($icon) {
+            $module->setIcon($icon);
+        }
+
+        $this->em->persist($module);
+
+        $this->logger->info(sprintf('Modul "%s" erstellt', $code));
+
+        return 'created';
+    }
+
+    /**
+     * Ermittelt die nächste Sort-Order
+     */
+    private function getNextSortOrder(): int
+    {
+        $maxSortOrder = $this->em->createQuery(
+            'SELECT MAX(m.sortOrder) FROM App\Entity\Module m'
+        )->getSingleScalarResult();
+
+        return ($maxSortOrder ?? 0) + 10;
+    }
+
+    /**
+     * Versucht, ein passendes Icon zu raten
+     */
+    private function guessIcon(string $code): ?string
+    {
+        $iconMap = [
+            'billing' => 'pi-file-pdf',
+            'invoicing' => 'pi-receipt',
+            'inventory' => 'pi-box',
+            'reporting' => 'pi-chart-bar',
+            'crm' => 'pi-users',
+            'test' => 'pi-code',
+        ];
+
+        return $iconMap[$code] ?? 'pi-circle';
+    }
+}
diff --git a/symfony.lock b/symfony.lock
index aee5f57..d7637f0 100644
--- a/symfony.lock
+++ b/symfony.lock
@@ -73,6 +73,9 @@
             "config/packages/knpu_oauth2_client.yaml"
         ]
     },
+    "mycrm/billing-module": {
+        "version": "dev-main"
+    },
     "mycrm/test-module": {
         "version": "dev-main"
     },