diff --git a/4_rust_tauri/src-tauri/Cargo.lock b/4_rust_tauri/src-tauri/Cargo.lock
index 623ceb5..03e7428 100644
--- a/4_rust_tauri/src-tauri/Cargo.lock
+++ b/4_rust_tauri/src-tauri/Cargo.lock
@@ -485,7 +485,7 @@ dependencies = [
 
 [[package]]
 name = "codeassist-tauri"
-version = "0.1.2"
+version = "0.1.3"
 dependencies = [
  "base64 0.22.1",
  "png 0.17.16",
diff --git a/5_django_backend/apps/gateway/langfuse.py b/5_django_backend/apps/gateway/langfuse.py
index cb99011..1cb6291 100644
--- a/5_django_backend/apps/gateway/langfuse.py
+++ b/5_django_backend/apps/gateway/langfuse.py
@@ -87,6 +87,8 @@ def trace(trace_id: str, name: str, *, userId: str = "", sessionId: str = "", in
         "langfuse.session.id": sessionId,
         "langfuse.trace.input": input,
         "langfuse.trace.output": output,
+        "langfuse.observation.input": input,  # 루트 span 본문에도 — 트레이스 화면이 루트 span 의 입출력을 보여줌(실측)
+        "langfuse.observation.output": output,
         "langfuse.trace.tags": tags,
         **{f"langfuse.trace.metadata.{k}": v for k, v in (metadata or {}).items()},
     }