diff --git a/backend/packages/harness/deerflow/agents/middlewares/uploads_middleware.py b/backend/packages/harness/deerflow/agents/middlewares/uploads_middleware.py
index d9cb5f8b0..58468765a 100644
--- a/backend/packages/harness/deerflow/agents/middlewares/uploads_middleware.py
+++ b/backend/packages/harness/deerflow/agents/middlewares/uploads_middleware.py
@@ -147,6 +147,13 @@ class UploadsMiddleware(AgentMiddleware[UploadsMiddlewareState]):
 
         # Resolve uploads directory for existence checks
         thread_id = (runtime.context or {}).get("thread_id")
+        if thread_id is None:
+            try:
+                from langgraph.config import get_config
+
+                thread_id = get_config().get("configurable", {}).get("thread_id")
+            except RuntimeError:
+                pass  # get_config() raises outside a runnable context (e.g. unit tests)
         uploads_dir = self._paths.sandbox_uploads_dir(thread_id) if thread_id else None
 
         # Get newly uploaded files from the current message's additional_kwargs.files