diff --git a/paperless-backend/src/paperless/paperless-processor.service.ts b/paperless-backend/src/paperless/paperless-processor.service.ts
index 9a54b6f..54d0913 100644
--- a/paperless-backend/src/paperless/paperless-processor.service.ts
+++ b/paperless-backend/src/paperless/paperless-processor.service.ts
@@ -1,5 +1,4 @@
 import { Injectable, Logger } from '@nestjs/common';
-import { Cron } from '@nestjs/schedule';
 import { ConfigService } from '@nestjs/config';
 import { InjectRepository } from '@nestjs/typeorm';
 import { Repository } from 'typeorm';
@@ -8,6 +7,8 @@ import { DocumentType } from '../database/entities/document-type.entity';
 import { PaperlessService } from './paperless.service';
 import { PostprocessingService } from '../postprocessing/postprocessing.service';
 
+const PAPERLESSMANAGER_TAG_ID = 16; // Tag "paperlessmanager"
+
 @Injectable()
 export class PaperlessProcessorService {
   private readonly logger = new Logger(PaperlessProcessorService.name);
@@ -22,11 +23,13 @@ export class PaperlessProcessorService {
     private readonly docFieldRepo: Repository<DocumentField>,
   ) {}
 
-  @Cron(process.env.PAPERLESS_PROCESSOR_CRON || '0 * * * * *')
+  // Manueller Batch-Lauf ("alle paperlessmanager-Dokumente neu durchlaufen").
+  // Die laufende Verarbeitung erfolgt ereignisgesteuert über den Webhook
+  // (processDocumentById), daher ist hier kein @Cron-Trigger mehr gesetzt.
   async processDocuments() {
     try {
       const response = await this.paperlessService.getDocuments({
-        tags__id__all: 16,
+        tags__id__all: PAPERLESSMANAGER_TAG_ID,
         page_size: 9999,
       });
       const documents: any[] = Array.isArray(response)
@@ -38,17 +41,12 @@ export class PaperlessProcessorService {
       const validFieldIds = new Set(customFields.map((f: any) => f.id));
 
       this.logger.log(
-        `Verarbeite ${documents.length} Dokument(e) mit Tag "paperlessmanager" (ID: 16).`,
+        `Verarbeite ${documents.length} Dokument(e) mit Tag "paperlessmanager" (ID: ${PAPERLESSMANAGER_TAG_ID}).`,
       );
 
       for (const doc of documents) {
         try {
-          const updatedDoc = await this.processSingleDocument(
-            doc,
-            validFieldIds,
-          );
-          // Postprocessing nach dem Speichern evaluieren
-          await this.postprocessingService.evaluate(updatedDoc || doc);
+          await this.processAndEvaluate(doc, validFieldIds);
         } catch (innerErr: any) {
           this.logger.error(
             `Fehler bei Dokument ID ${doc.id}: ${innerErr.message}`,
@@ -65,6 +63,45 @@ export class PaperlessProcessorService {
     }
   }
 
+  /**
+   * Verarbeitet ein einzelnes Dokument anhand seiner ID – die ereignisgesteuerte
+   * Variante des früheren Cron-Jobs (vom Paperless-Webhook aufgerufen). Es wird
+   * nur verarbeitet, wenn das Dokument den Tag "paperlessmanager" trägt.
+   */
+  async processDocumentById(
+    documentId: number,
+  ): Promise<{ processed: boolean; reason?: string }> {
+    const doc = await this.paperlessService.getDocument(documentId);
+    const tags: number[] = doc.tags || [];
+    if (!tags.includes(PAPERLESSMANAGER_TAG_ID)) {
+      this.logger.log(
+        `Dokument ${documentId} ohne Tag "paperlessmanager" (ID ${PAPERLESSMANAGER_TAG_ID}) – übersprungen.`,
+      );
+      return { processed: false, reason: 'tag-missing' };
+    }
+
+    const customFields = await this.paperlessService.getCustomFields();
+    const validFieldIds = new Set<number>(customFields.map((f: any) => f.id));
+
+    await this.processAndEvaluate(doc, validFieldIds);
+    this.logger.log(`Dokument ${documentId} per Webhook verarbeitet.`);
+    return { processed: true };
+  }
+
+  /**
+   * Reichert ein Dokument an (Tags, Pflichtfelder, Titel) und evaluiert
+   * anschließend das Postprocessing. Gemeinsame Logik von Batch-Lauf und Webhook.
+   */
+  private async processAndEvaluate(
+    doc: any,
+    validFieldIds: Set<number>,
+  ): Promise<any> {
+    const updatedDoc = await this.processSingleDocument(doc, validFieldIds);
+    // Postprocessing nach dem Speichern evaluieren
+    await this.postprocessingService.evaluate(updatedDoc || doc);
+    return updatedDoc;
+  }
+
   private async processSingleDocument(
     doc: any,
     validFieldIds: Set<number>,
diff --git a/paperless-backend/src/paperless/paperless.module.ts b/paperless-backend/src/paperless/paperless.module.ts
index eb5db29..6b6f4c6 100644
--- a/paperless-backend/src/paperless/paperless.module.ts
+++ b/paperless-backend/src/paperless/paperless.module.ts
@@ -32,6 +32,6 @@ import { AuthModule } from '../auth/auth.module';
     PaperlessProcessorService,
     PaperlessTaskProcessorService,
   ],
-  exports: [PaperlessService],
+  exports: [PaperlessService, PaperlessProcessorService],
 })
 export class PaperlessModule {}
diff --git a/paperless-backend/src/webhook/webhook.controller.ts b/paperless-backend/src/webhook/webhook.controller.ts
index 8154711..0efe857 100644
--- a/paperless-backend/src/webhook/webhook.controller.ts
+++ b/paperless-backend/src/webhook/webhook.controller.ts
@@ -5,32 +5,78 @@ import {
   Logger,
   HttpCode,
   HttpStatus,
+  UseGuards,
+  BadRequestException,
 } from '@nestjs/common';
-import { Public } from '../auth/public.decorator';
+import { ApiKeyGuard } from '../auth/api-key.guard';
+import { PaperlessProcessorService } from '../paperless/paperless-processor.service';
+
 export interface PaperlessWebhookPayload {
-  document_id: number;
-  action: string;
+  doc_url?: string;
+  document_id?: number; // optional, für manuelles Testen
+  action?: string;
   [key: string]: any;
 }
 
-@Controller('webhook')
+@Controller('api/webhook')
 export class WebhookController {
   private readonly logger = new Logger(WebhookController.name);
 
-  @Public()
+  constructor(private readonly paperlessProcessor: PaperlessProcessorService) {}
+
+  @UseGuards(ApiKeyGuard)
   @Post('paperless')
   @HttpCode(HttpStatus.OK)
-  async handlePaperlessWebhook(
-    @Body() payload: PaperlessWebhookPayload,
-  ): Promise<{ status: string }> {
+  async handlePaperlessWebhook(@Body() payload: PaperlessWebhookPayload) {
+    const documentId = this.extractDocumentId(payload);
+    if (!documentId) {
+      this.logger.warn(
+        `Webhook ohne ermittelbare Dokument-ID: ${JSON.stringify(payload)}`,
+      );
+      throw new BadRequestException(
+        'Keine Dokument-ID aus doc_url/document_id ermittelbar',
+      );
+    }
+
     this.logger.log(
-      `Webhook empfangen: action=${payload.action}, document=${payload.document_id}`,
+      `Webhook: action=${payload.action}, document=${documentId}`,
     );
 
-    // TODO: Business-Logik für verschiedene Webhook-Events
-    // - document_updated → Felder prüfen, Postprocessing auslösen
-    // - document_consumed → GoBD-Archivierung prüfen
+    try {
+      const result =
+        await this.paperlessProcessor.processDocumentById(documentId);
+      return {
+        status: result.processed ? 'processed' : 'skipped',
+        reason: result.reason,
+      };
+    } catch (err) {
+      // Fehler tolerieren (wie der bisherige Cron) und 200 zurückgeben,
+      // damit Paperless keine Retry-Schleife startet.
+      const message = err instanceof Error ? err.message : String(err);
+      this.logger.error(
+        `Fehler bei Webhook-Verarbeitung von Dokument ${documentId}: ${message}`,
+      );
+      return { status: 'error', message };
+    }
+  }
 
-    return { status: 'received' };
+  /**
+   * Ermittelt die Dokument-ID aus dem Webhook-Payload. Bevorzugt wird das
+   * optionale Feld `document_id` (für manuelles Testen), andernfalls wird die
+   * ID aus dem Paperless-Platzhalter `{{doc_url}}` extrahiert
+   * (z.B. ".../documents/123/").
+   */
+  private extractDocumentId(payload: PaperlessWebhookPayload): number | null {
+    if (
+      payload?.document_id != null &&
+      !Number.isNaN(Number(payload.document_id))
+    ) {
+      return Number(payload.document_id);
+    }
+    if (typeof payload?.doc_url === 'string') {
+      const m = payload.doc_url.match(/\/documents\/(\d+)/);
+      if (m) return Number(m[1]);
+    }
+    return null;
   }
 }
diff --git a/paperless-backend/src/webhook/webhook.module.ts b/paperless-backend/src/webhook/webhook.module.ts
index b004812..466eb2e 100644
--- a/paperless-backend/src/webhook/webhook.module.ts
+++ b/paperless-backend/src/webhook/webhook.module.ts
@@ -1,7 +1,10 @@
 import { Module } from '@nestjs/common';
 import { WebhookController } from './webhook.controller';
+import { PaperlessModule } from '../paperless/paperless.module';
+import { AuthModule } from '../auth/auth.module';
 
 @Module({
+  imports: [PaperlessModule, AuthModule],
   controllers: [WebhookController],
 })
 export class WebhookModule {}