diff --git a/backend/scripts/hmip_control.py b/backend/scripts/hmip_control.py
new file mode 100644
index 0000000..494fa7b
--- /dev/null
+++ b/backend/scripts/hmip_control.py
@@ -0,0 +1,72 @@
+#!/usr/bin/env python3
+"""
+Steuerungs-Skript für das Homematic-IP-Türschloss.
+Nutzt AUTH_TOKEN/ACCESS_POINT aus Umgebungsvariablen (nicht als CLI-Argument,
+damit sie nicht in Prozesslisten/Logs auftauchen).
+
+Usage:
+  python3 hmip_control.py list-devices
+  python3 hmip_control.py lock <deviceId>
+  python3 hmip_control.py unlock <deviceId>
+
+Gibt bei list-devices JSON-Liste aller DoorLockDrive-Geräte aus
+({"id": ..., "label": ..., "lockState": ...}), sonst {"ok": true}.
+"""
+import asyncio
+import json
+import os
+import sys
+
+import homematicip
+from homematicip.base.enums import LockState
+from homematicip.connection.connection_context import ConnectionContextBuilder
+from homematicip.home import Home
+
+
+async def get_home():
+    access_point = os.environ["HMIP_ACCESS_POINT"]
+    auth_token = os.environ["HMIP_AUTH_TOKEN"]
+    context = await ConnectionContextBuilder.build_context_async(access_point, auth_token=auth_token)
+    home = Home()
+    await home.init_async(access_point, auth_token=auth_token)
+    await home.get_current_state_async()
+    return home
+
+
+async def main():
+    if len(sys.argv) < 2:
+        print(json.dumps({"error": "Kommando fehlt (list-devices|lock|unlock)"}))
+        sys.exit(1)
+
+    command = sys.argv[1]
+    home = await get_home()
+
+    door_locks = [d for d in home.devices if type(d).__name__.startswith("DoorLockDrive")]
+
+    if command == "list-devices":
+        print(json.dumps([
+            {"id": d.id, "label": d.label, "lockState": str(d.lockState)}
+            for d in door_locks
+        ]))
+        return
+
+    if command in ("lock", "unlock"):
+        if len(sys.argv) != 3:
+            print(json.dumps({"error": "deviceId fehlt"}))
+            sys.exit(1)
+        device_id = sys.argv[2]
+        target = next((d for d in door_locks if d.id == device_id), None)
+        if not target:
+            print(json.dumps({"error": f"Türschloss {device_id} nicht gefunden"}))
+            sys.exit(1)
+        state = LockState.LOCKED if command == "lock" else LockState.UNLOCKED
+        await target.set_lock_state_async(state)
+        print(json.dumps({"ok": True}))
+        return
+
+    print(json.dumps({"error": f"Unbekanntes Kommando: {command}"}))
+    sys.exit(1)
+
+
+if __name__ == "__main__":
+    asyncio.run(main())
diff --git a/backend/scripts/hmip_register.py b/backend/scripts/hmip_register.py
new file mode 100644
index 0000000..57e9680
--- /dev/null
+++ b/backend/scripts/hmip_register.py
@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+"""
+Nicht-interaktive Registrierung eines neuen Homematic-IP-Clients (analog zu
+homematicip.cli.hmip_generate_auth_token, aber ohne input()-Prompts, damit
+die Node-API sie als Hintergrundprozess starten und den Fortschritt pollen
+kann).
+
+Usage: python3 hmip_register.py <SGTIN> <STATUS_FILE>
+
+Schreibt fortlaufend JSON-Status nach STATUS_FILE:
+  {"state": "waiting_for_button"}
+  {"state": "success", "authToken": "...", "accessPoint": "...", "clientId": "..."}
+  {"state": "error", "message": "..."}
+"""
+import asyncio
+import json
+import sys
+
+import homematicip.auth
+from homematicip.connection.connection_context import ConnectionContextBuilder
+from homematicip.connection.rest_connection import RestConnection
+
+
+def write_status(path, data):
+    with open(path, "w") as f:
+        json.dump(data, f)
+
+
+async def main():
+    if len(sys.argv) != 3:
+        print("Usage: hmip_register.py <SGTIN> <STATUS_FILE>", file=sys.stderr)
+        sys.exit(1)
+
+    access_point = sys.argv[1].replace("-", "").upper()
+    status_file = sys.argv[2]
+
+    if len(access_point) != 24:
+        write_status(status_file, {"state": "error", "message": "Ungültige SGTIN (erwartet 24 Zeichen ohne Bindestriche)"})
+        sys.exit(1)
+
+    try:
+        context = await ConnectionContextBuilder.build_context_async(access_point)
+        connection = RestConnection(context, log_status_exceptions=False)
+        auth = homematicip.auth.Auth(connection, context.client_auth_token, access_point)
+
+        response = await auth.connection_request(access_point, "wg-verwaltung")
+        if response.status != 200:
+            body = json.loads(response.text)
+            write_status(status_file, {"state": "error", "message": body.get("errorCode", "Unbekannter Fehler")})
+            sys.exit(1)
+
+        write_status(status_file, {"state": "waiting_for_button"})
+
+        attempts = 0
+        while not await auth.is_request_acknowledged():
+            attempts += 1
+            if attempts > 180:  # 180 * 2s = 6 Minuten Timeout
+                write_status(status_file, {"state": "error", "message": "Zeitüberschreitung: Knopf am Access Point wurde nicht rechtzeitig gedrückt"})
+                sys.exit(1)
+            await asyncio.sleep(2)
+
+        auth_token = await auth.request_auth_token()
+        client_id = await auth.confirm_auth_token(auth_token)
+
+        write_status(status_file, {
+            "state": "success",
+            "authToken": auth_token,
+            "accessPoint": access_point,
+            "clientId": client_id,
+        })
+    except Exception as e:
+        write_status(status_file, {"state": "error", "message": str(e)})
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    asyncio.run(main())
diff --git a/backend/src/app.ts b/backend/src/app.ts
index 0c882c3..7c37e23 100644
--- a/backend/src/app.ts
+++ b/backend/src/app.ts
@@ -17,6 +17,7 @@ import { contractsRouter } from './routes/contracts';
 import { utilityStatementsRouter } from './routes/utilityStatements';
 import { craftsmenRouter } from './routes/craftsmen';
 import { ratingsRouter } from './routes/ratings';
+import { smartLockRouter } from './routes/smartLock';
 
 export function createApp() {
   const app = express();
@@ -52,6 +53,7 @@ export function createApp() {
   app.use('/v1', utilityStatementsRouter);
   app.use('/v1', craftsmenRouter);
   app.use('/v1', ratingsRouter);
+  app.use('/v1', smartLockRouter);
 
   app.get('/health', (_req, res) => res.status(200).json({ ok: true }));
 
diff --git a/backend/src/routes/smartLock.ts b/backend/src/routes/smartLock.ts
new file mode 100644
index 0000000..0ac57cd
--- /dev/null
+++ b/backend/src/routes/smartLock.ts
@@ -0,0 +1,117 @@
+import { Router, Response } from 'express';
+import { spawn } from 'child_process';
+import fs from 'fs';
+import path from 'path';
+import { AuthedRequest, requireAuth, requireRole } from '../middleware/auth';
+
+/**
+ * Steuerung des Homematic-IP-Türschlosses (Access Point + App, kein
+ * lokaler CCU-Zugriff). Da Homematic IP für dieses Setup keine offizielle
+ * Partner-API anbietet, wird die aktiv gepflegte, quelloffene Community-
+ * Bibliothek `homematicip` (Python) über zwei Skripte angesprochen
+ * (backend/scripts/hmip_register.py, hmip_control.py) statt das
+ * Cloud-Protokoll selbst nachzubauen.
+ *
+ * Echte Steuerung ist erst nutzbar, wenn HMIP_ACCESS_POINT/HMIP_AUTH_TOKEN
+ * gesetzt sind (per einmaliger Kopplung über /smartlock/pairing/*, dabei
+ * muss der blaue Knopf am Access Point physisch gedrückt werden).
+ */
+export const smartLockRouter = Router();
+
+const SCRIPTS_DIR = path.join(__dirname, '..', '..', 'scripts');
+const PAIRING_STATUS_FILE = path.join('/tmp', 'hmip_pairing_status.json');
+
+function runPythonScript(script: string, args: string[], env: NodeJS.ProcessEnv = process.env): Promise<{ stdout: string; stderr: string; code: number }> {
+  return new Promise((resolve) => {
+    const proc = spawn('python3', [path.join(SCRIPTS_DIR, script), ...args], { env });
+    let stdout = '';
+    let stderr = '';
+    proc.stdout.on('data', (d) => (stdout += d.toString()));
+    proc.stderr.on('data', (d) => (stderr += d.toString()));
+    proc.on('close', (code) => resolve({ stdout, stderr, code: code ?? 1 }));
+  });
+}
+
+function hmipConfigured(): boolean {
+  return Boolean(process.env.HMIP_ACCESS_POINT && process.env.HMIP_AUTH_TOKEN);
+}
+
+// Startet die einmalige Kopplung (Landlord/Admin). Läuft im Hintergrund,
+// da bis zu ~6 Minuten auf den Knopfdruck am Access Point gewartet wird.
+smartLockRouter.post(
+  '/smartlock/pairing/start',
+  requireAuth,
+  requireRole('LANDLORD', 'ADMIN'),
+  async (req: AuthedRequest, res: Response) => {
+    const { sgtin } = req.body || {};
+    if (!sgtin || typeof sgtin !== 'string') {
+      return res.status(400).json({ error: 'sgtin ist erforderlich' });
+    }
+
+    try {
+      fs.writeFileSync(PAIRING_STATUS_FILE, JSON.stringify({ state: 'starting' }));
+    } catch {
+      return res.status(500).json({ error: 'Konnte Status-Datei nicht anlegen' });
+    }
+
+    const proc = spawn('python3', [path.join(SCRIPTS_DIR, 'hmip_register.py'), sgtin, PAIRING_STATUS_FILE], {
+      detached: true,
+      stdio: 'ignore',
+    });
+    proc.unref();
+
+    res.status(202).json({ message: 'Kopplung gestartet. Bitte jetzt den blauen Knopf am Access Point drücken (bis zu 6 Minuten Zeit). Status via GET /smartlock/pairing/status abfragen.' });
+  },
+);
+
+smartLockRouter.get(
+  '/smartlock/pairing/status',
+  requireAuth,
+  requireRole('LANDLORD', 'ADMIN'),
+  async (_req: AuthedRequest, res: Response) => {
+    if (!fs.existsSync(PAIRING_STATUS_FILE)) {
+      return res.status(200).json({ state: 'idle' });
+    }
+    try {
+      const data = JSON.parse(fs.readFileSync(PAIRING_STATUS_FILE, 'utf-8'));
+      res.status(200).json(data);
+    } catch {
+      res.status(200).json({ state: 'idle' });
+    }
+  },
+);
+
+smartLockRouter.get('/smartlock/status', requireAuth, async (_req: AuthedRequest, res: Response) => {
+  res.status(200).json({ configured: hmipConfigured() });
+});
+
+smartLockRouter.get('/smartlock/devices', requireAuth, requireRole('LANDLORD', 'ADMIN'), async (_req: AuthedRequest, res: Response) => {
+  if (!hmipConfigured()) {
+    return res.status(409).json({ error: 'Homematic IP ist noch nicht gekoppelt (siehe /smartlock/pairing/start)' });
+  }
+  const { stdout, stderr, code } = await runPythonScript('hmip_control.py', ['list-devices']);
+  if (code !== 0) {
+    return res.status(502).json({ error: 'Abfrage fehlgeschlagen', detail: stderr || stdout });
+  }
+  try {
+    res.status(200).json({ devices: JSON.parse(stdout) });
+  } catch {
+    res.status(502).json({ error: 'Unerwartete Antwort von Homematic IP', detail: stdout });
+  }
+});
+
+smartLockRouter.post(
+  '/smartlock/devices/:deviceId/:action(lock|unlock)',
+  requireAuth,
+  async (req: AuthedRequest, res: Response) => {
+    if (!hmipConfigured()) {
+      return res.status(409).json({ error: 'Homematic IP ist noch nicht gekoppelt (siehe /smartlock/pairing/start)' });
+    }
+    const { deviceId, action } = req.params;
+    const { stdout, stderr, code } = await runPythonScript('hmip_control.py', [action, deviceId]);
+    if (code !== 0) {
+      return res.status(502).json({ error: 'Türsteuerung fehlgeschlagen', detail: stderr || stdout });
+    }
+    res.status(200).json({ ok: true });
+  },
+);