diff --git a/tools/atree/fs.h b/tools/atree/fs.h
new file mode 100644
index 0000000..4080880
--- /dev/null
+++ b/tools/atree/fs.h
@@ -0,0 +1,12 @@
+#ifndef FS_H
+#define FS_H
+
+#include <string>
+
+using namespace std;
+
+int remove_recursively(const string& path);
+int mkdir_recursively(const string& path);
+int copy_file(const string& src, const string& dst);
+
+#endif // FS_H