diff --git a/backend/src/db.js b/backend/src/db.js
index c68656c..849c87c 100644
--- a/backend/src/db.js
+++ b/backend/src/db.js
@@ -177,4 +177,44 @@ if (!oiCols.includes('qty_in_arbeit'))   db.exec("ALTER TABLE order_items ADD CO
 if (!oiCols.includes('qty_fertig'))      db.exec("ALTER TABLE order_items ADD COLUMN qty_fertig INTEGER NOT NULL DEFAULT 0");
 // Bestehende Einträge: alle Stücke auf Warteliste setzen falls noch keine Qtys gesetzt
 db.exec("UPDATE order_items SET qty_warteliste=stueckzahl WHERE qty_warteliste=0 AND qty_in_arbeit=0 AND qty_fertig=0");
+
+// ── Nachrichten-Migrationen ───────────────────────────────────────────────────
+if (!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='messages'").get()) {
+  db.exec(`
+    CREATE TABLE messages (
+      id                  INTEGER PRIMARY KEY AUTOINCREMENT,
+      sender_id           INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+      recipient_id        INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+      encrypted_content   TEXT NOT NULL,
+      iv                  TEXT NOT NULL,
+      created_at          DATETIME DEFAULT CURRENT_TIMESTAMP,
+      deleted_by_sender   INTEGER NOT NULL DEFAULT 0,
+      deleted_by_recipient INTEGER NOT NULL DEFAULT 0,
+      read_by_recipient   INTEGER NOT NULL DEFAULT 0
+    )
+  `);
+}
+if (!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='user_keys'").get()) {
+  db.exec(`
+    CREATE TABLE user_keys (
+      user_id    INTEGER PRIMARY KEY REFERENCES users(id) ON DELETE CASCADE,
+      public_key TEXT NOT NULL,
+      updated_at DATETIME DEFAULT NULL
+    )
+  `);
+}
+if (!db.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='pushover_settings'").get()) {
+  db.exec(`
+    CREATE TABLE pushover_settings (
+      user_id   INTEGER PRIMARY KEY REFERENCES users(id) ON DELETE CASCADE,
+      user_key  TEXT NOT NULL,
+      app_token TEXT NOT NULL
+    )
+  `);
+}
+// Falls messages-Tabelle alt ist und read_by_recipient fehlt
+const msgCols = db.prepare("PRAGMA table_info(messages)").all().map(r => r.name);
+if (msgCols.length && !msgCols.includes('read_by_recipient'))
+  db.exec("ALTER TABLE messages ADD COLUMN read_by_recipient INTEGER NOT NULL DEFAULT 0");
+
 module.exports = db;