diff --git a/frontend/src/config.example.js b/frontend/src/config.example.js
index ec32ef4..54152ab 100644
--- a/frontend/src/config.example.js
+++ b/frontend/src/config.example.js
@@ -1,6 +1,21 @@
-// Frontend-Konfiguration — VOR dem Build anpassen, dann als config.js speichern
+// Frontend-Konfiguration — als config.js speichern vor dem Build
 // config.js ist in .gitignore und wird NICHT eingecheckt
+//
+// Priorität: 1. window.__RMM_CONFIG__ (Docker Runtime-Injection)
+//            2. Vite ENV-Variablen (.env / --env beim Build)
+//            3. Fallback-Werte hier
+//
+// Docker-Beispiel (nginx config.js-Injection):
+//   window.__RMM_CONFIG__ = { backendHost: "192.168.1.10", backendPort: "8443", apiKey: "abc123" }
+//
+// .env-Beispiel:
+//   VITE_BACKEND_HOST=192.168.1.10
+//   VITE_BACKEND_PORT=8443
+//   VITE_API_KEY=abc123
 
-export const BACKEND_HOST = 'BACKEND_IP_ODER_HOSTNAME'
-export const BACKEND_URL = `https://${BACKEND_HOST}:8443`
-export const API_KEY = 'DEIN_API_KEY'
+const rt = window.__RMM_CONFIG__ || {}
+
+export const BACKEND_HOST = rt.backendHost || import.meta.env.VITE_BACKEND_HOST || 'localhost'
+export const BACKEND_PORT = rt.backendPort || import.meta.env.VITE_BACKEND_PORT || '8443'
+export const BACKEND_URL = `https://${BACKEND_HOST}:${BACKEND_PORT}`
+export const API_KEY = rt.apiKey || import.meta.env.VITE_API_KEY || ''