@@ -0,0 +1,10 @@
+---
+'@object-ui/app-shell': patch
+---
+
+fix(app-shell): the screen-flow dialog refuses an empty required field at the field, as the record form does
+
+Clause-②: no
+Metadata-protocol: none
+
+Submit on a flow screen with a required field left empty used to answer with one toast naming the fields and nothing in the dialog, so it read as a button that did nothing. Each missing field now shows "FIELD is required" under its control, the control is marked `aria-invalid` and names the message in `aria-describedby`, focus moves to the first missing field, and Submit stays. No toast is raised and no resume request is made, matching the record form. Editing a field clears its message. A retryable refusal from the engine keeps the screen, the typed values and Submit as before; a run the engine has already ended still offers only Close.
@@ -251,6 +251,31 @@
  *   exactly as before.
  * The `object-form` step's own button (`flowRunner.saveAndContinue`) is the
  * form's, and is not relabelled here.
+ *
+ * ## An empty required field is refused AT the field (objectstack#26882)
+ *
+ * Submit with a required field left empty used to answer with one toast
+ * naming the fields and nothing else: no message at the field, no
+ * `aria-invalid`, focus left on Submit. A toast is transient and sits apart
+ * from the dialog, so the refusal read as a button that did nothing. The
+ * dialog now answers the way the record form does, and only that way: each
+ * missing field shows `validation.required` ("Due Date is required") under its
+ * control, the control is marked `aria-invalid` and names the message in its
+ * `aria-describedby` ({@link ScreenView}), and focus moves to the first missing
+ * field in screen order. There is no toast — the record form raises none for a
+ * client-side refusal either, since every field it refuses carries its own
+ * message. Submit stays where it was, and no resume request is made. Editing a
+ * field retires its own message; the next Submit checks again.
+ *
+ * What this does NOT cover, on purpose: a refusal that comes back from the
+ * ENGINE. A retryable one (`INVALID_SCREEN_INPUT`, the declared field
+ * contract, checked before the suspension is consumed) keeps the screen, the
+ * values and Submit, with the sentence in the banner above — the envelope
+ * names no field in a structured slot, so placing it at a field would mean
+ * parsing prose. A terminal one (a `refused` end, or a node failing after the
+ * resume consumed the suspension) withdraws Submit as the sections above say:
+ * the run is over, and only a new run, or an operator's
+ * `restore-suspension`, can accept input again.
  */
 import { Suspense, useEffect, useState } from 'react';
 import {
@@ -282,6 +307,7 @@ import {
   isObjectFormScreen,
   initialScreenValues,
   screenFieldBoundViolations,
+  screenFieldControlId,
   screenFields,
   screenResumeValues,
   visibleScreenFields,
@@ -471,6 +497,9 @@ export function FlowRunner({ state, authFetch, baseUrl, onClose, onComplete, dat
   const [submitting, setSubmitting] = useState(false);
   const [resumeError, setResumeError] = useState<ResumeError | null>(null);
   const [refused, setRefused] = useState<RefusedOutcome | null>(null);
+  // The message each field the last Submit refused is drawn with, by field
+  // name (objectstack#26882 — see the header).
+  const [fieldErrors, setFieldErrors] = useState<Record<string, string>>({});
   // Every upload widget in the screen body reports into this scope, so Submit
   // can wait for a file field's id (objectstack#25801 — see the header).
   const uploads = useUploadingScope();
@@ -485,6 +514,7 @@ export function FlowRunner({ state, authFetch, baseUrl, onClose, onComplete, dat
       // A fresh run must not open under the previous run's refusal.
       setResumeError(null);
       setRefused(null);
+      setFieldErrors({});
     }
   }, [state]);
 
@@ -495,7 +525,7 @@ export function FlowRunner({ state, authFetch, baseUrl, onClose, onComplete, dat
   // it follows the live resource tree and a language switch with no identity
   // to keep stable (AGENTS.md §5 #10). `screen` stays the payload the run is
   // driven by; `shown` differs from it in copy only, so every DISPLAY read —
-  // including the names in the missing-fields toast below — goes through it.
+  // including the labels the required refusal below names — goes through it.
   const bundle = activeFlowsBundle(i18n, language, flowName);
   const shown = localizeScreen(screen, flowName, bundle, language);
   // The flow's name as the user reads it (objectui#11092), from the same bundle.
@@ -507,6 +537,14 @@ export function FlowRunner({ state, authFetch, baseUrl, onClose, onComplete, dat
     // where a retry exists. A terminal refusal must stay on screen: its whole
     // job is to explain why the (now absent) Submit is not coming back.
     setResumeError((e) => (e && e.retryable ? null : e));
+    // The field's own refusal goes with the edit that answers it; the others
+    // stay until they are answered too.
+    setFieldErrors((p) => {
+      if (!(name in p)) return p;
+      const next = { ...p };
+      delete next[name];
+      return next;
+    });
   };
 
   // Resume the paused run with `inputs` (applied as bare flow variables) and
@@ -561,6 +599,7 @@ export function FlowRunner({ state, authFetch, baseUrl, onClose, onComplete, dat
       setRunId(outcome.runId || runId);
       setFlowLabel(outcome.flowLabel);
       setValues(initialScreenValues(outcome.screen));
+      setFieldErrors({});
       // Only a step that saved a record says so; a flat step's answer is the
       // next screen itself (objectstack#26578 — see the header).
       if (savedRecord) toast.success(t('flowRunner.nextStep', { defaultValue: 'Saved — next step' }));
@@ -601,15 +640,26 @@ export function FlowRunner({ state, authFetch, baseUrl, onClose, onComplete, dat
     const missing = visibleScreenFields(shown, values).filter(
       (f) => f.required && (values[f.name] === undefined || values[f.name] === '' || values[f.name] === null),
     );
+    // Refused at each field, as the record form refuses it, with no toast and
+    // no request (objectstack#26882 — see the header). The names come from
+    // `shown`, so the message reads the field's label in the user's language.
     if (missing.length) {
-      toast.error(
-        t('wizard.missingRequired', {
-          fields: missing.map((f) => f.label || f.name).join(', '),
-          defaultValue: 'Please complete the required fields: {{fields}}',
-        }),
+      setFieldErrors(
+        Object.fromEntries(
+          missing.map((f) => [
+            f.name,
+            t('validation.required', { field: f.label || f.name, defaultValue: '{{field}} is required' }),
+          ]),
+        ),
       );
+      // The first missing field in screen order takes focus, so the refusal is
+      // where the user is looking, on a long screen too.
+      const first = document.getElementById(screenFieldControlId(missing[0].name));
+      first?.focus({ preventScroll: true });
+      first?.scrollIntoView?.({ block: 'center' });
       return;
     }
+    setFieldErrors({});
     // The declared `min` / `max` (objectstack#17306), refused here naming the
     // field, beside `required` and over the same on-screen list. A courtesy,
     // not the enforcement: the engine re-checks the bounds on resume, and
@@ -748,6 +798,7 @@ export function FlowRunner({ state, authFetch, baseUrl, onClose, onComplete, dat
                   screen={shown}
                   values={values}
                   onValueChange={setVal}
+                  errors={fieldErrors}
                   dataSource={dataSource}
                   objects={objects}
                   // Two columns from `sm` up; `space-y-0` replaces the body's own
 
@@ -84,6 +84,18 @@
  * form's `BooleanField` in its checkbox face, with the label BESIDE the control
  * and the help text under the row. The generic layout put the label on one line
  * and a lone checkbox on the next, which read as an empty radio button.
+ *
+ * ## A refused field says so under its control (objectstack#26882)
+ *
+ * `errors` maps a field name to the message the caller refused it with (the
+ * runtime's `required` check). The message is drawn under the control as the
+ * record form's `FormMessage` draws it, and the control is marked the way the
+ * record form marks it: `aria-invalid`, and the message's id in its
+ * `aria-describedby` beside any help text. A platform widget (picker, upload,
+ * lookup, checkbox) receives the message as its published `error` slot, which
+ * it reads only to set `aria-invalid` on its own control; the text stays here,
+ * so it is drawn once. A field absent from `errors` renders as before, and the
+ * Studio preview passes none.
  */
 import { Suspense } from 'react';
 import { Link, useInRouterContext, useParams } from 'react-router-dom';
@@ -343,6 +355,19 @@ function screenFieldHelpId(name: string): string {
   return `ff-${name}-help`;
 }
 
+/** The id of a screen field's refusal message, which its control names in `aria-describedby`. */
+function screenFieldErrorId(name: string): string {
+  return `ff-${name}-error`;
+}
+
+/**
+ * The id of the control a screen field draws, the one its label points at.
+ * Exported so the runtime can move focus to a refused field (objectstack#26882).
+ */
+export function screenFieldControlId(name: string): string {
+  return `ff-${name}`;
+}
+
 /** Submit/cancel wiring for the object-form body — runtime persists & resumes;
  *  the design preview hides the bar (`showSubmit`/`showCancel` false). */
 export interface ScreenObjectFormActions {
@@ -372,10 +397,15 @@ export interface ScreenViewProps {
    */
   objects?: any[];
   objectForm?: ScreenObjectFormActions;
+  /**
+   * The message each refused field is drawn with, by field name (see the
+   * header, objectstack#26882). Absent, or a field not in it, draws no message.
+   */
+  errors?: Readonly<Record<string, string>>;
   className?: string;
 }
 
-export function ScreenView({ screen, values, onValueChange, dataSource, objects, objectForm, className }: ScreenViewProps) {
+export function ScreenView({ screen, values, onValueChange, dataSource, objects, objectForm, errors, className }: ScreenViewProps) {
   if (isObjectFormScreen(screen)) {
     const objectDef = Array.isArray(objects) ? objects.find((o: any) => o?.name === screen.objectName) : undefined;
     const subforms = objectDef
@@ -422,16 +452,25 @@ export function ScreenView({ screen, values, onValueChange, dataSource, objects,
         // placeholder (which the browser clears on the first keystroke), and
         // the control names it in `aria-describedby` so it is announced too.
         const helpId = f.inlineHelpText ? screenFieldHelpId(f.name) : undefined;
+        // A refused field names its message too, after the help text, as the
+        // record form's control does (objectstack#26882).
+        const error = errors?.[f.name] || undefined;
+        const errorId = error ? screenFieldErrorId(f.name) : undefined;
+        const describedBy = [helpId, errorId].filter(Boolean).join(' ') || undefined;
         const input = (
           <ScreenFieldInput
             field={f}
             value={values[f.name]}
             onChange={(v) => onValueChange(f.name, v)}
-            describedBy={helpId}
+            describedBy={describedBy}
+            error={error}
             dataSource={dataSource}
             objects={objects}
           />
         );
+        const message = errorId && (
+          <p id={errorId} className="text-sm font-medium text-destructive" data-screen-field-error={f.name}>{error}</p>
+        );
         // The boolean control sits BESIDE its label, `ActionParamDialog`'s
         // inline row; the help text lines up under the label.
         if (isBooleanScreenField(f)) {
@@ -449,6 +488,7 @@ export function ScreenView({ screen, values, onValueChange, dataSource, objects,
               {helpId && (
                 <p id={helpId} className="text-xs text-muted-foreground ml-6">{f.inlineHelpText}</p>
               )}
+              {message && <div className="ml-6">{message}</div>}
             </div>
           );
         }
@@ -467,6 +507,7 @@ export function ScreenView({ screen, values, onValueChange, dataSource, objects,
             {helpId && (
               <p id={helpId} className="text-xs text-muted-foreground">{f.inlineHelpText}</p>
             )}
+            {message}
           </div>
         );
       })}
@@ -489,21 +530,29 @@ export function ScreenFieldInput({
   value,
   onChange,
   describedBy,
+  error,
   dataSource,
   objects,
 }: {
   field: ScreenFieldSpec;
   value: unknown;
   onChange: (v: unknown) => void;
-  /** Id of the element describing this control (its help text), for `aria-describedby`. */
+  /** Ids of the elements describing this control (its help text, its refusal), for `aria-describedby`. */
   describedBy?: string;
+  /**
+   * The message this field was refused with (objectstack#26882). A platform
+   * widget takes it as its `error` slot, which sets `aria-invalid` on its own
+   * control; a plain control gets `aria-invalid` here. The text itself is
+   * drawn by {@link ScreenView}.
+   */
+  error?: string;
   /** Data source a `type: 'lookup'` picker queries its `reference` object through. */
   dataSource?: unknown;
   /** The console's object definitions: the objects a `record_link` field may link to a page of. */
   objects?: ReadonlyArray<unknown>;
 }) {
   const { t } = useObjectTranslation();
-  const id = `ff-${field.name}`;
+  const id = screenFieldControlId(field.name);
   const kind = (field.type || 'text').toLowerCase();
   // The required STATE, announced on the control itself — the label's `*` is
   // visual-only (objectui#10367). `aria-required`, not native `required`: the
@@ -512,6 +561,8 @@ export function ScreenFieldInput({
   // browser's own verdict beside it — on a checkbox it means "must be checked".
   // `undefined` when optional, so the attribute is omitted rather than "false".
   const ariaRequired = field.required ? true : undefined;
+  // The refused STATE, for the plain controls below; omitted when not refused.
+  const ariaInvalid = error ? true : undefined;
 
   // The read-only record link (objectstack#25872): the record's display name,
   // drawn by the lookup widget's `readonly` branch, inside a link to its page.
@@ -538,6 +589,7 @@ export function ScreenFieldInput({
           onChange={onChange}
           field={{ name: field.name, label: field.label, type: 'lookup', reference: field.reference, placeholder: field.placeholder }}
           dataSource={dataSource}
+          error={error}
           aria-required={ariaRequired}
           aria-describedby={describedBy}
         />
@@ -558,6 +610,7 @@ export function ScreenFieldInput({
           value={value ?? null}
           onChange={onChange}
           field={{ name: field.name, label: field.label, type: 'file', placeholder: field.placeholder }}
+          error={error}
           aria-required={ariaRequired}
           aria-describedby={describedBy}
         />
@@ -583,7 +636,7 @@ export function ScreenFieldInput({
     };
     return (
       <Select value={value != null ? flowScreenFieldOptionKey(value) : undefined} onValueChange={pickOption}>
-        <SelectTrigger id={id} aria-required={ariaRequired} aria-describedby={describedBy}><SelectValue placeholder={placeholder} /></SelectTrigger>
+        <SelectTrigger id={id} aria-required={ariaRequired} aria-invalid={ariaInvalid} aria-describedby={describedBy}><SelectValue placeholder={placeholder} /></SelectTrigger>
         <SelectContent>
           {options.map((o, i) => (
             <SelectItem key={i} value={flowScreenFieldOptionKey(o.value)}>{o.label}</SelectItem>
@@ -606,6 +659,7 @@ export function ScreenFieldInput({
           onChange={(checked: unknown) => onChange(checked === true)}
           field={{ name: field.name, label: field.label, type: 'boolean', widget: 'checkbox' }}
           className="mt-0.5"
+          error={error}
           aria-required={ariaRequired}
           aria-describedby={describedBy}
         />
@@ -624,14 +678,15 @@ export function ScreenFieldInput({
           value={value ?? null}
           onChange={onChange}
           field={{ name: field.name, label: field.label, type: kind }}
+          error={error}
           aria-required={ariaRequired}
           aria-describedby={describedBy}
         />
       </Suspense>
     );
   }
   if (kind === 'textarea' || kind === 'markdown') {
-    return <Textarea id={id} aria-required={ariaRequired} aria-describedby={describedBy} value={(value as string) ?? ''} placeholder={field.placeholder} onChange={(e) => onChange(e.target.value)} />;
+    return <Textarea id={id} aria-required={ariaRequired} aria-invalid={ariaInvalid} aria-describedby={describedBy} value={(value as string) ?? ''} placeholder={field.placeholder} onChange={(e) => onChange(e.target.value)} />;
   }
   const htmlType = kind === 'number' || kind === 'currency' ? 'number' : kind === 'email' ? 'email' : 'text';
   // The declared bound pair goes on a NUMERIC input only, as the native
@@ -642,6 +697,7 @@ export function ScreenFieldInput({
     <Input
       id={id}
       aria-required={ariaRequired}
+      aria-invalid={ariaInvalid}
       aria-describedby={describedBy}
       type={htmlType}
       min={numeric ? field.min : undefined}
 
@@ -136,8 +136,10 @@ describe('objectstack#25801 — a `type: \'file\'` screen field is the platform
 
     fireEvent.click(screen.getByRole('button', { name: 'Submit' }));
 
-    await waitFor(() => expect(toasts.error).toHaveBeenCalledTimes(1));
-    expect(String(toasts.error.mock.calls[0][0])).toContain('Contract');
+    // Refused at the field (objectstack#26882), naming it, with no toast.
+    await waitFor(() => expect(document.querySelector('[data-screen-field-error]')).not.toBeNull());
+    expect(document.querySelector('[data-screen-field-error]')?.textContent).toContain('Contract');
+    expect(toasts.error).not.toHaveBeenCalled();
     expect(authFetch).not.toHaveBeenCalled();
   });
 
 
@@ -136,7 +136,7 @@ describe('FlowRunner — the `flows` translation overlay (objectui#5920)', () =>
     expect(dialog.queryByPlaceholderText('e.g. Annual renewal')).not.toBeInTheDocument();
   });
 
-  it('names the translated label in the missing-required toast, not the authored one', async () => {
+  it('names the translated label in the missing-required refusal, not the authored one', async () => {
     const user = userEvent.setup();
     const instance = i18nWith('zh-CN', 'zh-CN', ZH_CN);
     renderRunner(CONVERSION, instance);
@@ -146,8 +146,10 @@ describe('FlowRunner — the `flows` translation overlay (objectui#5920)', () =>
     // than spelled here.
     await user.click(screen.getByRole('button', { name: instance.t('common.submit') }));
 
-    await waitFor(() => expect(toasts.error).toHaveBeenCalledTimes(1));
-    const message = String(toasts.error.mock.calls[0][0]);
+    // The refusal is drawn at the field (objectstack#26882), not toasted.
+    await waitFor(() => expect(document.querySelector('[data-screen-field-error]')).not.toBeNull());
+    expect(toasts.error).not.toHaveBeenCalled();
+    const message = String(document.querySelector('[data-screen-field-error]')?.textContent);
     expect(message).toContain('商机名称');
     expect(message).not.toContain('Opportunity Name');
   });