diff --git a/include/tdata/ctrie.h b/include/tdata/ctrie.h
new file mode 100644
index 0000000..ae23c69
--- /dev/null
+++ b/include/tdata/ctrie.h
@@ -0,0 +1,42 @@
+/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 2; tab-width: 2 -*- */
+/*
+ * cas.c
+ * Copyright (C) 2015 Alexander Vdolainen <avdolainen@gmail.com>
+ *
+ * libtdata is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libtdata is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.";
+ */
+
+#ifndef __TDATA_CTRIE_H__
+#define __TDATA_CTRIE_H__
+
+#include "../config.h"
+
+/* flags */
+#define CTRIE_FLAG_RO  (1 << 1)
+
+/* structure Ctrie (flags is also underlying node type) */
+typedef struct __ctrie_type {
+  int flags;
+  void **root;
+}__attribute__((packed)) ctrie_t;
+
+/* structure SNode (key-value node) */
+typedef struct __ctrie_snode {
+	ct_key_t key;
+	void *value;
+}__attribute__((packed)) ct_snode_t;
+
+
+
+#endif /* __TDATA_CTRIE_H__ */