diff --git a/server-rs/crates/api-server/src/tripo3d/errors.rs b/server-rs/crates/api-server/src/tripo3d/errors.rs
index bb669088e..9970365e1 100644
--- a/server-rs/crates/api-server/src/tripo3d/errors.rs
+++ b/server-rs/crates/api-server/src/tripo3d/errors.rs
@@ -73,6 +73,7 @@ pub(crate) fn map_provider_error(error: TripoError) -> AppError {
 pub(crate) fn oss_unavailable(message: &str) -> AppError {
     AppError::from_status(StatusCode::SERVICE_UNAVAILABLE).with_details(json!({
         "provider": "aliyun-oss",
+        "reason": "oss-unavailable",
         "message": message,
     }))
 }