diff --git a/backend/TODO.md b/backend/TODO.md
index 5036c32..97c68e0 100644
--- a/backend/TODO.md
+++ b/backend/TODO.md
@@ -7,4 +7,5 @@
 
 ## Issues
 
+[ ] Make sure that no duplicated files in `state.artifacts`
 [ ] Long thinking but with empty content (answer inside thinking process)