diff --git a/www/src/models/index.ts b/www/src/models/index.ts
index 2e5a5b7..52f16aa 100644
--- a/www/src/models/index.ts
+++ b/www/src/models/index.ts
@@ -68,7 +68,11 @@ export function useStores(): IStore {
 export type { Property, DataType } from "./ontology/Property";
 export type { SMEdge, SMNode } from "./sm/SMGraph";
 export type { Table, TableRow } from "./table";
-export type { TransformationResult, Transformation } from "./transformation";
+export type {
+  TransformationResult,
+  Transformation,
+  DraftCreateTransformation,
+} from "./transformation";
 export {
   ProjectStore,
   TableStore,
diff --git a/www/src/models/transformation/TransformationStore.ts b/www/src/models/transformation/TransformationStore.ts
index adc1d41..ab5e639 100644
--- a/www/src/models/transformation/TransformationStore.ts
+++ b/www/src/models/transformation/TransformationStore.ts
@@ -9,21 +9,30 @@ export interface Transformation extends Record<number> {
   tableId: number;
   datapath: string[];
   code: string | undefined;
+  onError: string;
   outputpath: string[] | undefined;
+}
+
+export interface DraftCreateTransformation extends Transformation {
   tolerance: number;
   rows: number;
 }
 
-export class TransformationStore extends SimpleCRUDStore<
+export class TransformationStore extends CRUDStore<
   number,
-  Transformation
+  Omit<DraftCreateTransformation, "id"> & { draftID: string },
+  DraftCreateTransformation & {
+    markSaved(): void;
+    toModel(): DraftCreateTransformation | undefined;
+  },
+  DraftCreateTransformation
 > {
   constructor() {
     super(`${SERVER}/api/transformation`, undefined, false);
   }
 
   async testTransformation(
-    payload: Transformation
+    payload: DraftCreateTransformation
   ): Promise<TransformationResult[] | undefined> {
     let resp: any = await axios
       .post(`${SERVER}/api/transformation/test`, {
diff --git a/www/src/pages/table/forms/TransformationForm.tsx b/www/src/pages/table/forms/TransformationForm.tsx
index 773d607..2464e94 100644
--- a/www/src/pages/table/forms/TransformationForm.tsx
+++ b/www/src/pages/table/forms/TransformationForm.tsx
@@ -18,7 +18,7 @@ import Editor from "@monaco-editor/react";
 import {
   TransformationResult,
   useStores,
-  Transformation,
+  DraftCreateTransformation,
   Table as TableModel,
 } from "../../../models";
 
@@ -83,12 +83,13 @@ export const TransformationForm = observer(
     ];
 
     const onExecute = async () => {
-      const transformationPayload: Transformation = {
+      const transformationPayload: DraftCreateTransformation = {
         id: -1,
         tableId: table.id,
         type: form.getFieldValue("type"),
         code: form.getFieldValue("code"),
         mode: "restrictedpython",
+        onError: form.getFieldValue("onerror"),
         datapath: form.getFieldValue("datapath"),
         outputpath: form.getFieldValue("outputpath"),
         tolerance: form.getFieldValue("tolerance"),