diff --git a/src/ifcopenshell-python/ifcopenshell/file.py b/src/ifcopenshell-python/ifcopenshell/file.py
index 134200a1e3..d7d240fa6a 100644
--- a/src/ifcopenshell-python/ifcopenshell/file.py
+++ b/src/ifcopenshell-python/ifcopenshell/file.py
@@ -32,7 +32,8 @@ from typing import TYPE_CHECKING
 from typing import Union
 from typing import overload
 from typing import Literal
-from typing import Any
+from typing import TypedDict
+from typing_extensions import assert_never
 
 from . import ifcopenshell_wrapper
 from .entity_instance import entity_instance
@@ -42,6 +43,31 @@ from ifcopenshell.util.mvd_info import MvdInfo, LARK_AVAILABLE
 if TYPE_CHECKING:
     import ifcopenshell.util.schema
 
+    InverseReference = tuple[int, Any]
+    ElementInverses = dict[int, list[InverseReference]]
+
+    class CreateOperation(TypedDict):
+        action: Literal["create"]
+        value: Any
+
+    class EditOperation(TypedDict):
+        action: Literal["edit"]
+        id: int
+        index: int
+        old: Any
+        new: Any
+
+    class DeleteOperation(TypedDict):
+        action: Literal["delete"]
+        inverses: ElementInverses
+        value: Any
+
+    class BatchDeleteOperation(TypedDict):
+        action: Literal["batch_delete"]
+        inverses: ElementInverses
+
+    TransactionOperation = Union[CreateOperation, EditOperation, DeleteOperation, BatchDeleteOperation]
+
 HEADER_FIELDS = {
     "file_description": [
         "description",
@@ -66,6 +92,10 @@ class UndoSystemError(Exception):
 
 
 class Transaction:
+    operations: list[TransactionOperation]
+    batch_inverses: list[ElementInverses]
+    batch_delete_ids: set[int]
+
     def __init__(self, ifc_file: file):
         self.file: file = ifc_file
         self.operations = []
@@ -80,14 +110,14 @@ class Transaction:
             info[key] = self.serialise_value(element, value)
         return info
 
-    def serialise_value(self, element, value):
+    def serialise_value(self, element, value) -> Any:
         return element.walk(
             lambda v: isinstance(v, entity_instance),
             lambda v: {"id": v.id()} if v.id() else {"type": v.is_a(), "value": v.wrappedValue},
             value,
         )
 
-    def unserialise_value(self, element, value):
+    def unserialise_value(self, element, value) -> Any:
         return element.walk(
             lambda v: isinstance(v, dict),
             lambda v: self.file.by_id(v["id"]) if v.get("id") else self.file.create_entity(v["type"], v["value"]),
@@ -137,10 +167,10 @@ class Transaction:
             {"action": "delete", "inverses": inverses, "value": self.serialise_entity_instance(element)}
         )
 
-    def get_element_inverses(self, element):
-        inverses = {}
+    def get_element_inverses(self, element: ifcopenshell.entity_instance) -> ElementInverses:
+        inverses: ElementInverses = {}
         for inverse in self.file.get_inverse(element):
-            inverse_references = []
+            inverse_references: list[InverseReference] = []
             for i, attribute in enumerate(inverse):
                 if self.has_element_reference(attribute, element):
                     inverse_references.append((i, self.serialise_value(inverse, attribute)))
@@ -187,6 +217,8 @@ class Transaction:
                     inverse = self.file.by_id(inverse_id)
                     for index, value in data:
                         inverse[index] = self.unserialise_value(inverse, value)
+            else:
+                assert_never(operation["action"])
 
     def commit(self) -> None:
         for operation in self.operations:
@@ -206,6 +238,8 @@ class Transaction:
                 self.file.remove(element)
             elif operation["action"] == "batch_delete":
                 pass
+            else:
+                assert_never(operation["action"])
 
 
 file_dict = {}
@@ -235,6 +269,10 @@ class file:
     wrapped_data: ifcopenshell_wrapper.file
     units: dict[str, entity_instance] = {}
     history_size: int = 64
+    history: list[Transaction]
+    """Chronological order - from oldest to newest."""
+    future: list[Transaction]
+    """Reversed chronological order - from newest to oldest."""
 
     to_delete: Union[set[ifcopenshell.entity_instance], None] = None
     """Entities for batch removal."""