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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

backend/packages/harness/deerflow/agents/middlewares/memory_middleware.py

@@ -57,10 +57,10 @@ class MemoryMiddleware(AgentMiddleware[MemoryMiddlewareState]):
         if not config.enabled:
             return None
 
-        # Get thread ID from runtime context
+        # Resolve thread ID from the runtime or configured fallback sources
         thread_id = get_thread_id(runtime)
         if not thread_id:
-            logger.debug("No thread_id in context, skipping memory update")
+            logger.debug("No thread_id could be resolved from runtime/config, skipping memory update")
             return None
 
         # Get messages from state

backend/packages/harness/deerflow/sandbox/tools.py

@@ -854,7 +854,9 @@ def ensure_sandbox_initialized(runtime: ToolRuntime[ContextT, ThreadState] | Non
     # Lazy acquisition: get thread_id and acquire sandbox
     thread_id = get_thread_id(runtime)
     if thread_id is None:
-        raise SandboxRuntimeError("Thread ID not available in runtime context")
+        raise SandboxRuntimeError(
+            "Thread ID not available in runtime context, runtime config, or LangGraph config"
+        )
 
     provider = get_sandbox_provider()
     sandbox_id = provider.acquire(thread_id)

backend/packages/harness/deerflow/tools/builtins/present_file_tool.py

@@ -36,7 +36,9 @@ def _normalize_presented_filepath(
 
     thread_id = get_thread_id(runtime)
     if not thread_id:
-        raise ValueError("Thread ID is not available in runtime context or runtime config")
+        raise ValueError(
+            "Thread ID is not available in runtime context, runtime config, or LangGraph thread-local config"
+        )
 
     thread_data = runtime.state.get("thread_data") or {}
     outputs_path = thread_data.get("outputs_path")

backend/packages/harness/deerflow/utils/runtime.py

@@ -83,6 +83,8 @@ def get_thread_id(runtime: Any | None) -> str | None:
         if thread_id:
             return thread_id
     except RuntimeError:
+        # Expected when not running inside a LangGraph runnable context (e.g., unit tests).
+        # In that case, thread_id cannot be resolved from thread-local config, so fall through.
         pass
 
     return None

backend/tests/test_runtime_utils.py

@@ -45,7 +45,8 @@ class TestGetThreadId:
 
     def test_returns_none_when_get_config_raises_runtime_error(self):
         runtime = SimpleNamespace(context=None, config={})
-        assert get_thread_id(runtime) is None
+        with patch("langgraph.config.get_config", side_effect=RuntimeError):
+            assert get_thread_id(runtime) is None
 
     def test_handles_object_without_context_or_config(self):
         runtime = SimpleNamespace()