diff --git a/libs/api/room/reaction.rs b/libs/api/room/reaction.rs
index 8673a6e..caa3aab 100644
--- a/libs/api/room/reaction.rs
+++ b/libs/api/room/reaction.rs
@@ -20,7 +20,8 @@ pub struct MessageSearchQuery {
 
 #[derive(Debug, serde::Deserialize, IntoParams)]
 pub struct ReactionBatchQuery {
-    pub message_ids: Vec<Uuid>,
+    /// Comma-separated list of message IDs
+    pub message_ids: String,
 }
 
 #[utoipa::path(
@@ -148,9 +149,14 @@ pub async fn reaction_batch(
         .user()
         .ok_or_else(|| ApiError::from(service::error::AppError::Unauthorized))?;
     let ctx = WsUserContext::new(user_id);
+    let message_ids: Vec<Uuid> = query
+        .message_ids
+        .split(',')
+        .filter_map(|s| Uuid::parse_str(s.trim()).ok())
+        .collect();
     let resp = service
         .room
-        .message_reactions_batch(room_id, query.into_inner().message_ids, &ctx)
+        .message_reactions_batch(room_id, message_ids, &ctx)
         .await
         .map_err(ApiError::from)?;
     Ok(ApiResponse::ok(resp).to_response())