diff --git a/tests/test_post.py b/tests/test_post.py
index e3848cf4..af9e5832 100644
--- a/tests/test_post.py
+++ b/tests/test_post.py
@@ -18,48 +18,12 @@ def patch_mock_api_helper(mocker) -> None:
     )
 
 
-class MockFieldData:
-    def __init__(self, solver_data, field_info):
-        self._session_data = solver_data
-        self._request_to_serve = {"surf": [], "scalar": [], "vector": []}
-        self._field_info = field_info
+class MockFieldTransaction:
+    def __init__(self, session_data, field_request):
+        self.service = session_data
+        self.fields_request = field_request
 
-    def get_surface_data(
-        self,
-        surface_name: str,
-        data_type: Union[SurfaceDataType, int],
-        overset_mesh: Optional[bool] = False,
-    ) -> Dict:
-        surfaces_info = self._field_info().get_surfaces_info()
-        surface_ids = surfaces_info[surface_name]["surface_id"]
-        self._request_to_serve["surf"].append(
-            (
-                surface_ids,
-                overset_mesh,
-                data_type == SurfaceDataType.Vertices,
-                data_type == SurfaceDataType.FacesConnectivity,
-                data_type == SurfaceDataType.FacesCentroid,
-                data_type == SurfaceDataType.FacesNormal,
-            )
-        )
-        enum_to_field_name = {
-            SurfaceDataType.FacesConnectivity: "faces",
-            SurfaceDataType.Vertices: "vertices",
-            SurfaceDataType.FacesCentroid: "centroid",
-            SurfaceDataType.FacesNormal: "face-normal",
-        }
-
-        tag_id = 0
-        if overset_mesh:
-            tag_id = self._payloadTags[FieldDataProtoModule.PayloadTag.OVERSET_MESH]
-        return {
-            surface_id: self._session_data["fields"][tag_id][surface_id][
-                enum_to_field_name[data_type]
-            ]
-            for surface_id in surface_ids
-        }
-
-    def add_get_surfaces_request(
+    def add_surfaces_request(
         self,
         surface_ids: List[int],
         overset_mesh: bool = False,
@@ -68,7 +32,7 @@ def add_get_surfaces_request(
         provide_faces_centroid=False,
         provide_faces_normal=False,
     ) -> None:
-        self._request_to_serve["surf"].append(
+        self.fields_request["surf"].append(
             (
                 surface_ids,
                 overset_mesh,
@@ -79,27 +43,27 @@ def add_get_surfaces_request(
             )
         )
 
-    def add_get_scalar_fields_request(
+    def add_scalar_fields_request(
         self,
         surface_ids: List[int],
         field_name: str,
         node_value: Optional[bool] = True,
         boundary_value: Optional[bool] = False,
     ) -> None:
-        self._request_to_serve["scalar"].append(
+        self.fields_request["scalar"].append(
             (surface_ids, field_name, node_value, boundary_value)
         )
 
-    def add_get_vector_fields_request(
+    def add_vector_fields_request(
         self,
         surface_ids: List[int],
-        vector_field: Optional[str] = "velocity",
+        field_name: str,
     ) -> None:
-        self._request_to_serve["vector"].append((surface_ids, vector_field))
+        self.fields_request["vector"].append((surface_ids, field_name))
 
     def get_fields(self) -> Dict[int, Dict]:
         fields = {}
-        for request_type, requests in self._request_to_serve.items():
+        for request_type, requests in self.fields_request.items():
             for request in requests:
                 if request_type == "surf":
                     tag_id = 0
@@ -118,12 +82,55 @@ def get_fields(self) -> Dict[int, Dict]:
                     surface_requests = field_requests.get(surf_id)
                     if not surface_requests:
                         surface_requests = field_requests[surf_id] = {}
-                    surface_requests.update(
-                        self._session_data["fields"][tag_id][surf_id]
-                    )
+                    surface_requests.update(self.service["fields"][tag_id][surf_id])
         return fields
 
 
+class MockFieldData:
+    def __init__(self, solver_data, field_info):
+        self._session_data = solver_data
+        self._request_to_serve = {"surf": [], "scalar": [], "vector": []}
+        self._field_info = field_info
+
+    def new_transaction(self):
+        return MockFieldTransaction(self._session_data, self._request_to_serve)
+
+    def get_surface_data(
+        self,
+        surface_name: str,
+        data_type: Union[SurfaceDataType, int],
+        overset_mesh: Optional[bool] = False,
+    ) -> Dict:
+        surfaces_info = self._field_info().get_surfaces_info()
+        surface_ids = surfaces_info[surface_name]["surface_id"]
+        self._request_to_serve["surf"].append(
+            (
+                surface_ids,
+                overset_mesh,
+                data_type == SurfaceDataType.Vertices,
+                data_type == SurfaceDataType.FacesConnectivity,
+                data_type == SurfaceDataType.FacesCentroid,
+                data_type == SurfaceDataType.FacesNormal,
+            )
+        )
+        enum_to_field_name = {
+            SurfaceDataType.FacesConnectivity: "faces",
+            SurfaceDataType.Vertices: "vertices",
+            SurfaceDataType.FacesCentroid: "centroid",
+            SurfaceDataType.FacesNormal: "face-normal",
+        }
+
+        tag_id = 0
+        if overset_mesh:
+            tag_id = self._payloadTags[FieldDataProtoModule.PayloadTag.OVERSET_MESH]
+        return {
+            surface_id: self._session_data["fields"][tag_id][surface_id][
+                enum_to_field_name[data_type]
+            ]
+            for surface_id in surface_ids
+        }
+
+
 class MockFieldInfo:
     def __init__(self, solver_data):
         self._session_data = solver_data
@@ -186,16 +193,18 @@ def test_field_api():
     # Get vertices
     vertices_data = field_data.get_surface_data("wall", SurfaceDataType.Vertices)
 
+    transaction = field_data.new_transaction()
+
     # Get multiple fields
-    field_data.add_get_surfaces_request(
+    transaction.add_surfaces_request(
         surfaces_id[:1],
         provide_vertices=True,
         provide_faces_centroid=True,
         provide_faces=False,
     )
-    field_data.add_get_scalar_fields_request(surfaces_id[:1], "temperature", True)
-    field_data.add_get_scalar_fields_request(surfaces_id[:1], "temperature", False)
-    fields = field_data.get_fields()
+    transaction.add_scalar_fields_request(surfaces_id[:1], "temperature", True)
+    transaction.add_scalar_fields_request(surfaces_id[:1], "temperature", False)
+    fields = transaction.get_fields()
 
     surface_tag = 0
     vertices = fields[surface_tag][surfaces_id[0]]["vertices"]