diff --git a/main.js b/main.js
index 670c402..bf4b651 100644
--- a/main.js
+++ b/main.js
@@ -18,7 +18,9 @@ const { createAccountPicker } = require('./lib/account-rotation');
 const ClouddropUploader = require('./lib/clouddrop-upload');
 const { checkForUpdate, prepareUpdate, launchPreparedUpdate, abortUpdate, createUpdateAnnouncementState } = require('./lib/updater');
 const backupCrypto = require('./lib/backup-crypto');
-const { createOnlineBackup, downloadOnlineBackup, uploadOnlineBackup } = require('./lib/online-backup');
+const { downloadOnlineBackup } = require('./lib/online-backup');
+const { createOnlineBackupKeyring } = require('./lib/online-backup-keyring');
+const { createOnlineBackupManager } = require('./lib/online-backup-manager');
 const { createPortableSettingsSnapshot, prepareImportedSettings } = require('./lib/settings-backup');
 const { createSettingsImportGate } = require('./lib/settings-import-gate');
 const FolderMonitor = require('./lib/folder-monitor');
@@ -119,6 +121,18 @@ let dropTargetWindow = null;
 let tray = null;
 const configStore = new ConfigStore(app);
 configStore.setPerfLog((m) => { try { logInfo(m); } catch {} });
+const onlineBackupKeyring = createOnlineBackupKeyring({
+  filePath: path.join(app.getPath('userData'), 'online-backup-keys.json')
+});
+const onlineBackupManager = createOnlineBackupManager({
+  keyring: onlineBackupKeyring,
+  loadSettings: async () => {
+    await waitForConfigStoreWrites();
+    return createPortableSettingsSnapshot(configStore.load());
+  },
+  appVersion: () => app.getVersion(),
+  copyText: value => clipboard.writeText(value)
+});
 let uploadManager = null;
 let lastSessionSummary = null;
 let sourceDeleteJournal = null;
@@ -154,6 +168,17 @@ async function waitForConfigStoreWrites() {
   await configStore.drainWrites();
 }
 
+function requireCanonicalOnlineBackupId(id) {
+  if (typeof id !== 'string' || !/^[A-Za-z0-9_-]{22}$/.test(id)) {
+    throw new Error('Online-Sicherungs-ID ist ungültig');
+  }
+  const decoded = Buffer.from(id, 'base64url');
+  if (decoded.length !== 16 || decoded.toString('base64url') !== id) {
+    throw new Error('Online-Sicherungs-ID ist ungültig');
+  }
+  return id;
+}
+
 function clearCloseFlushTimer() {
   if (closeFlushTimer) clearTimeout(closeFlushTimer);
   closeFlushTimer = null;
@@ -2781,13 +2806,21 @@ ipcMain.handle('import-backup', async (_event, legacyPassword) => {
   }
 });
 
-ipcMain.handle('online-backup:create', async () => {
+ipcMain.handle('online-backup:list-managed', () => onlineBackupManager.listManaged());
+
+ipcMain.handle('online-backup:create-managed', () => onlineBackupManager.createManaged());
+
+ipcMain.handle('online-backup:copy-managed', (_event, id) => {
   try {
-    await waitForConfigStoreWrites();
-    const snapshot = createPortableSettingsSnapshot(configStore.load());
-    const created = createOnlineBackup(snapshot, app.getVersion());
-    await uploadOnlineBackup(created.record);
-    return { ok: true, key: created.key };
+    return onlineBackupManager.copyManaged(requireCanonicalOnlineBackupId(id));
+  } catch (error) {
+    return { ok: false, error: error.message || String(error) };
+  }
+});
+
+ipcMain.handle('online-backup:delete-managed', (_event, id) => {
+  try {
+    return onlineBackupManager.deleteManaged(requireCanonicalOnlineBackupId(id));
   } catch (error) {
     return { ok: false, error: error.message || String(error) };
   }
diff --git a/preload.js b/preload.js
index e2eaf64..8dff4f5 100644
--- a/preload.js
+++ b/preload.js
@@ -79,7 +79,11 @@ contextBridge.exposeInMainWorld('api', {
   // Backup
   exportBackup: (options) => ipcRenderer.invoke('export-backup', options),
   importBackup: (legacyPassword) => ipcRenderer.invoke('import-backup', legacyPassword),
-  createOnlineBackup: () => ipcRenderer.invoke('online-backup:create'),
+  listManagedOnlineBackups: () => ipcRenderer.invoke('online-backup:list-managed'),
+  createManagedOnlineBackup: () => ipcRenderer.invoke('online-backup:create-managed'),
+  copyManagedOnlineBackup: (id) => ipcRenderer.invoke('online-backup:copy-managed', id),
+  deleteManagedOnlineBackup: (id) => ipcRenderer.invoke('online-backup:delete-managed', id),
+  createOnlineBackup: () => ipcRenderer.invoke('online-backup:create-managed'),
   restoreOnlineBackup: (key) => ipcRenderer.invoke('online-backup:restore', key),
 
   // Folder Monitor
diff --git a/tests/package-build-files.test.js b/tests/package-build-files.test.js
index 1bd6c17..6a4be5a 100644
--- a/tests/package-build-files.test.js
+++ b/tests/package-build-files.test.js
@@ -1,15 +1,39 @@
 const test = require('node:test');
 const assert = require('node:assert/strict');
+const fs = require('node:fs');
 const Module = require('node:module');
 const path = require('node:path');
 const packageJson = require('../package.json');
 
+const projectRoot = path.join(__dirname, '..');
+
 test('packages every Electron preload referenced by the main process', () => {
   assert.ok(packageJson.build.files.includes('preload.js'));
   assert.ok(packageJson.build.files.includes('preload-drop-target.js'));
+  assert.ok(packageJson.build.files.includes('lib/**/*'));
   assert.equal(packageJson.build.win.signAndEditExecutable, false);
 });
 
+test('exposes managed online backup operations through narrow IPC boundaries', () => {
+  const preloadSource = fs.readFileSync(path.join(projectRoot, 'preload.js'), 'utf8');
+  const mainSource = fs.readFileSync(path.join(projectRoot, 'main.js'), 'utf8');
+
+  assert.match(preloadSource, /listManagedOnlineBackups:\s*\(\)\s*=>\s*ipcRenderer\.invoke\('online-backup:list-managed'\)/u);
+  assert.match(preloadSource, /createManagedOnlineBackup:\s*\(\)\s*=>\s*ipcRenderer\.invoke\('online-backup:create-managed'\)/u);
+  assert.match(preloadSource, /copyManagedOnlineBackup:\s*\(id\)\s*=>\s*ipcRenderer\.invoke\('online-backup:copy-managed',\s*id\)/u);
+  assert.match(preloadSource, /deleteManagedOnlineBackup:\s*\(id\)\s*=>\s*ipcRenderer\.invoke\('online-backup:delete-managed',\s*id\)/u);
+  assert.match(preloadSource, /createOnlineBackup:\s*\(\)\s*=>\s*ipcRenderer\.invoke\('online-backup:create-managed'\)/u);
+  assert.doesNotMatch(preloadSource, /ipcRenderer\.invoke\('online-backup:create'\)/u);
+  assert.match(mainSource, /path\.join\(app\.getPath\('userData'\),\s*'online-backup-keys\.json'\)/u);
+  assert.match(mainSource, /Buffer\.from\(id,\s*'base64url'\)/u);
+  assert.match(mainSource, /decoded\.toString\('base64url'\)\s*!==\s*id/u);
+  assert.doesNotMatch(mainSource, /ipcMain\.handle\('online-backup:create'/u);
+  assert.match(mainSource, /ipcMain\.handle\('online-backup:list-managed',[\s\S]*?onlineBackupManager\.listManaged\(\)/u);
+  assert.match(mainSource, /ipcMain\.handle\('online-backup:create-managed',[\s\S]*?onlineBackupManager\.createManaged\(\)/u);
+  assert.match(mainSource, /ipcMain\.handle\('online-backup:copy-managed',[\s\S]*?onlineBackupManager\.copyManaged\(/u);
+  assert.match(mainSource, /ipcMain\.handle\('online-backup:delete-managed',[\s\S]*?onlineBackupManager\.deleteManaged\(/u);
+});
+
 test('afterPack brands the executable metadata shown by Windows', async () => {
   let editCall = null;
   const originalLoad = Module._load;
diff --git a/tests/ui-smoke.js b/tests/ui-smoke.js
index ce17ec5..923d73b 100644
--- a/tests/ui-smoke.js
+++ b/tests/ui-smoke.js
@@ -1377,8 +1377,11 @@ setTimeout(async () => {
     const onlineBackupKeyContract = await wc.executeJavaScript('document.getElementById("onlineBackupKeyInput")?.maxLength + "|" + document.getElementById("onlineBackupKeyInput")?.getAttribute("pattern")');
     check('Online backup input enforces the 75-character MHU key format', onlineBackupKeyContract === '75|MHU2-[A-Za-z0-9_-]{70}');
 
-    const onlineBackupBridge = await wc.executeJavaScript('typeof window.api.createOnlineBackup + "|" + typeof window.api.restoreOnlineBackup');
-    check('Online backup uses a narrow preload bridge', onlineBackupBridge === 'function|function');
+    const onlineBackupBridge = await wc.executeJavaScript('["listManagedOnlineBackups", "createManagedOnlineBackup", "copyManagedOnlineBackup", "deleteManagedOnlineBackup"].map(name => typeof window.api[name]).join("|")');
+    check('Online backup uses a narrow managed preload bridge', onlineBackupBridge === 'function|function|function|function');
+
+    const managedOnlineBackupCopyResult = await wc.executeJavaScript('window.api.copyManagedOnlineBackup("AAAAAAAAAAAAAAAAAAAAAA").then(result => JSON.stringify(result))');
+    check('Managed online backup copy never returns a complete key', !managedOnlineBackupCopyResult.includes('MHU2-'));
 
     const invalidOnlineBackup = await wc.executeJavaScript('document.getElementById("onlineBackupKeyInput").value = "MHU2-short"; document.getElementById("onlineBackupKeyInput").dispatchEvent(new Event("input", { bubbles: true })); document.getElementById("restoreOnlineBackupBtn").disabled + "|" + document.getElementById("onlineBackupStatus").textContent');
     check('Invalid online backup keys stay blocked with visible guidance', invalidOnlineBackup === 'true|Der Schlüssel muss exakt 75 Zeichen lang sein.');