diff --git a/api/__init__.py b/api/__init__.py
index 4ea2a94..408e40e 100644
--- a/api/__init__.py
+++ b/api/__init__.py
@@ -2,6 +2,8 @@ from .project import have_project, create_project, delete_project
 from .project import is_project_open, open_project, close_project
 from .project import copy_project
 
+from .change_set import ChangeSet
+
 from .operation import execute_undo as undo
 from .operation import execute_redo as redo
 from .operation import have_snapshot, take_snapshot, pick_snapshot
diff --git a/api/change_set.py b/api/change_set.py
new file mode 100644
index 0000000..efedeff
--- /dev/null
+++ b/api/change_set.py
@@ -0,0 +1,14 @@
+class ChangeSet:
+    def __init__(self) -> None:
+        self.added : list[dict[str, str]] = {}
+        self.deleted : list[dict[str, str]] = {}
+        self.updated : list[dict[str, str]] = {}
+
+    def add(self, type: str, id: str) -> None:
+        self.added.append({ 'type': type, 'id': id })
+
+    def delete(self, type: str, id: str) -> None:
+        self.deleted.append({ 'type': type, 'id': id })
+
+    def update(self, type: str, id: str, property: str) -> None:
+        self.updated.append({ 'type': type, 'id': id, 'property': property })
\ No newline at end of file
diff --git a/tjnetwork_new.py b/tjnetwork_new.py
index f7a3845..e3661a8 100644
--- a/tjnetwork_new.py
+++ b/tjnetwork_new.py
@@ -1,6 +1,13 @@
 import api
 
 
+############################################################
+# ChangeSet
+############################################################
+
+ChangeSet = api.ChangeSet
+
+
 ############################################################
 # enum
 ############################################################