diff --git a/.env.example b/.env.example
index 335cb25..102a657 100644
--- a/.env.example
+++ b/.env.example
@@ -189,6 +189,21 @@ VIKUNJA_URL=https://tasks.feuerwehr-rems.at
 # WARNING: Keep this secret!
 VIKUNJA_API_TOKEN=your_vikunja_api_token
 
+# ============================================================================
+# FDISK SYNC CONFIGURATION
+# ============================================================================
+
+# FDISK login credentials
+# Used by the fdisk-sync service to scrape member data from app.fdisk.at
+# REQUIRED for the sync service to work
+FDISK_USERNAME=your_fdisk_username
+FDISK_PASSWORD=your_fdisk_password
+
+# Internal URL of the fdisk-sync control server
+# Used by the backend to proxy manual trigger and log requests
+# In Docker Compose this is fixed — only change if you remap the port
+FDISK_SYNC_URL=http://fdisk-sync:3001
+
 # ============================================================================
 # LOGGING CONFIGURATION (Optional)
 # ============================================================================
diff --git a/sync/.env.example b/sync/.env.example
index 85d7147..0f88db3 100644
--- a/sync/.env.example
+++ b/sync/.env.example
@@ -9,3 +9,7 @@ DB_PORT=5432
 DB_NAME=feuerwehr_prod
 DB_USER=prod_user
 DB_PASSWORD=
+
+# HTTP control server port (used by admin UI for manual trigger + logs)
+# Default: 3001
+SYNC_HTTP_PORT=3001