diff --git a/tests/test_integration.py b/tests/test_integration.py
new file mode 100644
index 0000000..46676a1
--- /dev/null
+++ b/tests/test_integration.py
@@ -0,0 +1,137 @@
+"""Integration-Tests für WhatsApp/Telegram-Webhook-Flows."""
+
+import hashlib
+import hmac
+from unittest.mock import MagicMock, patch
+
+from flask import Flask
+import pytest
+
+from src.app import create_app
+from src.routes.whatsapp import whatsapp_bp
+from src.routes.telegram import telegram_bp
+from src.routes.admin import admin_bp
+from src.queue.worker import verarbeite_submission, worker_loop
+
+
+@pytest.fixture()
+def flask_app() -> Flask:
+    """Erstellt Flask-App mit allen Blueprints."""
+    app = create_app()
+    app.queue_handler = MagicMock()
+    app.queue_handler.queue_size.return_value = 0
+    app.register_blueprint(whatsapp_bp, url_prefix="/")
+    app.register_blueprint(telegram_bp, url_prefix="/")
+    app.register_blueprint(admin_bp, url_prefix="/")
+    return app
+
+
+class TestWebhookIntegration:
+    """Tests für Webhook-Integration."""
+
+    def test_whatsapp_post_mit_gueltiger_signatur(self, flask_app: Flask) -> None:
+        """WhatsApp POST mit gültiger Signatur → 200, Submission in Queue."""
+        with patch("src.routes.whatsapp.verify_whatsapp_signature", return_value=True):
+            response = flask_app.test_client().post(
+                "/webhook/whatsapp",
+                data=b'{"object":"whatsapp","entry":[]}',
+                headers={"X-Hub-Signature-256": "sha256=test"},
+                content_type="application/json",
+            )
+            assert response.status_code == 200
+            data = response.get_json()
+            assert data["status"] == "accepted"
+            flask_app.queue_handler.enqueue.assert_called_once()
+
+    def test_whatsapp_post_mit_ungueltiger_signatur(self, flask_app: Flask) -> None:
+        """WhatsApp POST mit ungültiger Signatur → 401."""
+        with patch("src.routes.whatsapp.verify_whatsapp_signature", return_value=False):
+            response = flask_app.test_client().post(
+                "/webhook/whatsapp",
+                data=b'{"object":"whatsapp","entry":[]}',
+                headers={"X-Hub-Signature-256": "sha256=fake"},
+                content_type="application/json",
+            )
+            assert response.status_code == 401
+            data = response.get_json()
+            assert "error" in data
+
+
+class TestTelegramIntegration:
+    """Tests für Telegram-Integration."""
+
+    def test_telegram_post_mit_gueltigem_payload(self, flask_app: Flask) -> None:
+        """Telegram POST mit gültigem Payload → 200."""
+        response = flask_app.test_client().post(
+            "/webhook/telegram",
+            data={"message": {"message_id": "123", "chat": {"id": "456"}, "text": "Hallo"}},
+            content_type="application/json",
+        )
+        assert response.status_code == 200
+        data = response.get_json()
+        assert data["status"] == "accepted"
+        flask_app.queue_handler.enqueue.assert_called_once()
+
+
+class TestWorkerIntegration:
+    """Tests für Worker-Integration."""
+
+    def test_vollstaendiger_flow_whatsapp(self, flask_app: Flask) -> None:
+        """Vollständiger Flow: WhatsApp POST → Worker verarbeitet → Status 'erledigt'."""
+        mock_qh = flask_app.queue_handler
+        mock_submission = MagicMock()
+        mock_submission.message_id = "msg001"
+        mock_submission.zeitstempel = "2024-01-01T00:00:00"
+        mock_submission.absender = "+491****7890"
+        mock_submission.text = "suche Catan"
+        mock_submission.status = "neu"
+        mock_submission.enqueue.return_value = "stream_id"
+
+        # Simuliere: Submit wurde enqueued, dann vom Worker geholt
+        call_count = [0]
+
+        def dequeue_side_effect(count: int = 5):
+            call_count[0] += 1
+            if call_count[0] <= 1:
+                return [mock_submission]
+            return []
+
+        mock_qh.dequeue.side_effect = dequeue_side_effect
+
+        with (
+            patch("src.queue.worker.verarbeite_submission", return_value=True) as mock_verarb,
+            patch("src.queue.worker.time.sleep", return_value=None),
+        ):
+            worker_loop(mock_qh, poll_interval=0, batch_size=5)
+
+        assert mock_verarb.call_count == 1
+        assert mock_qh.mark_done.call_count == 1
+
+    def test_vollstaendiger_flow_telegram(self, flask_app: Flask) -> None:
+        """Vollständiger Flow: Telegram POST → Worker verarbeitet → Status 'erledigt'."""
+        mock_qh = flask_app.queue_handler
+        mock_submission = MagicMock()
+        mock_submission.message_id = "msg002"
+        mock_submission.zeitstempel = "2024-01-01T00:00:00"
+        mock_submission.absender = "@user123"
+        mock_submission.text = "hilfe"
+        mock_submission.status = "neu"
+
+        call_count = [0]
+
+        def dequeue_side_effect(count: int = 5):
+            call_count[0] += 1
+            if call_count[0] <= 1:
+                return [mock_submission]
+            return []
+
+        mock_qh.dequeue.side_effect = dequeue_side_effect
+
+        with (
+            patch("src.queue.worker.verarbeite_submission", return_value=True) as mock_verarb,
+            patch("src.queue.worker.time.sleep", return_value=None),
+        ):
+            worker_loop(mock_qh, poll_interval=0, batch_size=5)
+
+        assert mock_verarb.call_count == 1
+        assert mock_qh.mark_done.call_count == 1