diff --git a/services/commtest/src/backup_utils.rs b/services/commtest/src/backup_utils.rs
--- a/services/commtest/src/backup_utils.rs
+++ b/services/commtest/src/backup_utils.rs
@@ -3,3 +3,11 @@
 }
 
 pub use proto::backup_service_client::BackupServiceClient;
+
+pub struct BackupData {
+  pub user_id: String,
+  pub device_id: String,
+  pub backup_id: String,
+  pub backup_chunk_sizes: Vec<usize>,
+  pub logs_sizes: Vec<Vec<usize>>,
+}