diff --git a/extension/src/service-worker/router/popup-only.ts b/extension/src/service-worker/router/popup-only.ts
index 16f45b3..1f1e63a 100644
--- a/extension/src/service-worker/router/popup-only.ts
+++ b/extension/src/service-worker/router/popup-only.ts
@@ -382,6 +382,12 @@ export async function handle(
       await chrome.storage.local.set({ session_timeout: msg.config });
       return { ok: true };
     }
+
+    case 'export_backup':
+      return { ok: false, error: 'export_backup not yet implemented' };
+
+    case 'restore_backup':
+      return { ok: false, error: 'restore_backup not yet implemented' };
   }
 }
 
diff --git a/extension/src/shared/messages.ts b/extension/src/shared/messages.ts
index a669523..1788701 100644
--- a/extension/src/shared/messages.ts
+++ b/extension/src/shared/messages.ts
@@ -48,7 +48,14 @@ export type PopupMessage =
   | { type: 'purge_all_trash' }
   | { type: 'get_field_history'; id: ItemId }
   | { type: 'get_session_config' }
-  | { type: 'update_session_config'; config: SessionTimeoutConfig };
+  | { type: 'update_session_config'; config: SessionTimeoutConfig }
+  | { type: 'export_backup'; passphrase: string; includeImage: boolean }
+  | {
+      type: 'restore_backup';
+      bytes: ArrayBuffer;
+      passphrase: string;
+      newRemote: { hostType: 'gitea' | 'github'; hostUrl: string; repoPath: string; apiToken: string };
+    };
 
 // --- Messages a content script may send ---
 
@@ -153,8 +160,19 @@ export const POPUP_ONLY_TYPES: ReadonlySet<PopupMessage['type']> = new Set([
   'list_trashed', 'restore_item', 'purge_item', 'purge_all_trash',
   'get_field_history',
   'get_session_config', 'update_session_config',
+  'export_backup', 'restore_backup',
 ] as PopupMessage['type'][]);
 
+export interface ExportBackupResponse extends Extract<Response, { ok: true }> {
+  data: { bytes: ArrayBuffer };
+}
+
+export interface RestoreBackupResponse extends Extract<Response, { ok: true }> {
+  data: {
+    summary: { itemCount: number; attachmentCount: number; hasImage: boolean };
+  };
+}
+
 export const CONTENT_CALLABLE_TYPES: ReadonlySet<ContentMessage['type']> = new Set([
   'get_autofill_candidates', 'get_credentials', 'check_credential', 'blacklist_site',
   'capture_save_login',