diff --git a/apps/ai-game-creator-shell/src-tauri/src/agent/design_runtime.rs b/apps/ai-game-creator-shell/src-tauri/src/agent/design_runtime.rs
index a8bb580e9..959081636 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/agent/design_runtime.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/agent/design_runtime.rs
@@ -473,7 +473,7 @@ fn design_debug(root: &Path, kind: &str, data: Value) {
     type Entry = (PathBuf, Value);
     static QUEUE: OnceLock<std::sync::mpsc::SyncSender<Entry>> = OnceLock::new();
     let sender = QUEUE.get_or_init(|| {
-        let (sender, receiver) = std::sync::mpsc::sync_channel::<Entry>(16);
+        let (sender, receiver) = std::sync::mpsc::sync_channel::<Entry>(256);
         let _ = std::thread::Builder::new()
             .name("design-debug".into())
             .spawn(move || {
@@ -546,8 +546,26 @@ async fn request_design_provider(
             None,
         ));
         let result = if llm.stream {
+            let mut stream_sequence = 0_u64;
             client
                 .stream_run(request.clone(), |delta| {
+                    stream_sequence = stream_sequence.saturating_add(1);
+                    design_debug(
+                        root,
+                        "stream",
+                        json!({
+                            "turnId": turn_id,
+                            "requestIndex": session.turn.as_ref().map(|turn| turn.request_index),
+                            "attempt": attempt,
+                            "sequence": stream_sequence,
+                            "occurredAtUnixNanos": unix_timestamp_nanos().to_string(),
+                            "model": llm.model,
+                            "deltaChars": delta.delta_text.chars().count(),
+                            "accumulatedChars": delta.accumulated_text.chars().count(),
+                            "deltaText": delta.delta_text,
+                            "finishReason": delta.finish_reason,
+                        }),
+                    );
                     emit(design_event(
                         root,
                         &turn_id,