@@ -0,0 +1,10 @@
+---
+'@object-ui/app-shell': patch
+---
+
+fix(app-shell): the flow inspector's list field shows a stored string as one entry instead of an empty list
+
+Clause-②: no
+Metadata-protocol: none
+
+A notify node's `channels` may be a single string (`channels: 'email'`) or a list; the spec accepts both and the runtime reads the string as a one-item list. Studio's flow inspector read any non-list value as empty, so the field showed no channels and adding one saved a list without `email`. A stored non-blank string now reads as a one-entry list (trimmed, as the runtime does). An edit saves the list form (`['email', 'sms']`); a field left untouched keeps the stored string.
@@ -0,0 +1,85 @@
+// Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * #25999 — a stored bare string reads as a one-entry list.
+ *
+ * A notify node's `channels` is `string | string[]` in the spec, and the
+ * runtime reads `channels: 'email'` as `['email']`. The field used to read any
+ * non-array value as an empty list: it showed "no entries", and adding a
+ * channel committed a list without `email`, silently dropping it.
+ *
+ * The cases read the rendered rows and the committed value, never the internal
+ * list, so an implementation that parses the string but fails to show or keep
+ * it still fails here.
+ */
+
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { render, screen, cleanup, fireEvent } from '@testing-library/react';
+import { FlowStringListField } from './FlowStringListField';
+
+afterEach(cleanup);
+
+const LABELS = {
+  label: 'Channels',
+  addLabel: 'Add',
+  itemLabel: 'Item',
+  removeLabel: 'Remove',
+  emptyLabel: 'No entries',
+};
+
+function rowValues(): string[] {
+  return screen.queryAllByPlaceholderText('Item').map((el) => (el as HTMLInputElement).value);
+}
+
+describe('FlowStringListField — stored string value (#25999)', () => {
+  it('shows a stored string as one row', () => {
+    render(<FlowStringListField {...LABELS} value="email" onCommit={vi.fn()} />);
+    expect(rowValues()).toEqual(['email']);
+    expect(screen.queryByText('No entries')).toBeNull();
+  });
+
+  it('keeps the stored entry when another one is added, committing the list form', () => {
+    const onCommit = vi.fn();
+    render(<FlowStringListField {...LABELS} value="email" onCommit={onCommit} />);
+
+    fireEvent.click(screen.getByText('Add'));
+    const inputs = screen.getAllByPlaceholderText('Item');
+    expect(inputs).toHaveLength(2);
+    fireEvent.change(inputs[1], { target: { value: 'sms' } });
+    fireEvent.blur(inputs[1]);
+
+    expect(onCommit).toHaveBeenLastCalledWith(['email', 'sms']);
+  });
+
+  it('removing the only entry of a stored string commits undefined', () => {
+    const onCommit = vi.fn();
+    render(<FlowStringListField {...LABELS} value="email" onCommit={onCommit} />);
+
+    fireEvent.click(screen.getByLabelText('Remove'));
+
+    expect(onCommit).toHaveBeenLastCalledWith(undefined);
+    expect(rowValues()).toEqual([]);
+  });
+
+  it('trims the stored string, as the runtime does', () => {
+    render(<FlowStringListField {...LABELS} value="  email " onCommit={vi.fn()} />);
+    expect(rowValues()).toEqual(['email']);
+  });
+
+  it('reads a blank string as empty', () => {
+    render(<FlowStringListField {...LABELS} value="   " onCommit={vi.fn()} />);
+    expect(rowValues()).toEqual([]);
+    expect(screen.getByText('No entries')).toBeTruthy();
+  });
+
+  it('still reads a stored list as its rows', () => {
+    render(<FlowStringListField {...LABELS} value={['inbox', 'email']} onCommit={vi.fn()} />);
+    expect(rowValues()).toEqual(['inbox', 'email']);
+  });
+
+  it('does not commit on render, so an untouched string stays as stored', () => {
+    const onCommit = vi.fn();
+    render(<FlowStringListField {...LABELS} value="email" onCommit={onCommit} />);
+    expect(onCommit).not.toHaveBeenCalled();
+  });
+});
@@ -33,6 +33,20 @@ function rowsToList(rows: Row[]): string[] {
   return rows.map((r) => r.value.trim()).filter((v) => v !== '');
 }
 
+/**
+ * The stored value as a list. Some keys accept a bare string as well as a
+ * list — a notify node's `channels` is `string | string[]` in the spec, and the
+ * runtime reads `'email'` as `['email']` — so a non-blank string reads as a
+ * one-entry list (#25999). Reading it as empty showed the field blank, and the
+ * next edit committed a list without the stored entry. A commit writes the
+ * list form, which every such key accepts.
+ */
+function toList(value: unknown): string[] {
+  if (Array.isArray(value)) return value.map((v) => String(v));
+  if (typeof value === 'string' && value.trim() !== '') return [value.trim()];
+  return [];
+}
+
 export interface FlowStringListFieldProps {
   label: string;
   value: unknown;
@@ -57,10 +71,7 @@ export function FlowStringListField({
   emptyLabel,
   required,
 }: FlowStringListFieldProps) {
-  const external = React.useMemo(
-    () => (Array.isArray(value) ? value.map((v) => String(v)) : []),
-    [value],
-  );
+  const external = React.useMemo(() => toList(value), [value]);
   const [rows, setRows] = React.useState<Row[]>(() => toRows(external, []));
   const lastCommitted = React.useRef(JSON.stringify(external));