🔀 feat: Save Config Edits as One Change Batch Against the Loaded Revision

src/components/configuration/review/ChangeReview.test.tsx

@@ -56,6 +56,9 @@ function reviewFor(
     saving: false,
     sessionExpired: false,
     termsUrl: null,
+    conflict: false,
+    reloadLatest: vi.fn(),
+    mergeLatest: vi.fn().mockResolvedValue(undefined),
     saveIssues: [],
     title: 'Review',
     blocked: issues.some((issue) => issue.blocking),
@@ -99,6 +102,47 @@ describe('ChangeReview', () => {
     expect(link).toHaveAttribute('target', '_blank');
   });
 
+  it('offers to reload or merge when the target was saved elsewhere meanwhile', () => {
+    const review = reviewFor([{ fieldPath: 'registration.socialLogins', value: ['openid'] }], {
+      conflict: true,
+    });
+    render(<ChangeReview review={review} />);
+    const alert = screen.getByRole('alert');
+    expect(alert).toHaveTextContent('Changed elsewhere');
+    expect(alert).toHaveTextContent(/Base configuration was saved elsewhere/);
+    fireEvent.click(within(alert).getByRole('button', { name: 'Reload' }));
+    expect(review.reloadLatest).toHaveBeenCalledTimes(1);
+    fireEvent.click(within(alert).getByRole('button', { name: 'Merge and save' }));
+    expect(review.mergeLatest).toHaveBeenCalledTimes(1);
+  });
+
+  it('keeps the footer Save disabled while the conflict waits for Reload or Merge', () => {
+    const edit = [{ fieldPath: 'registration.socialLogins', value: ['openid'] }];
+    const { unmount } = render(<ChangeReview review={reviewFor(edit, { conflict: true })} />);
+    const footer = screen.getByRole('contentinfo');
+    expect(within(footer).getByRole('button', { name: 'Save' })).toBeDisabled();
+    unmount();
+    render(<ChangeReview review={reviewFor(edit)} />);
+    expect(screen.getByRole('button', { name: 'Save' })).toBeEnabled();
+  });
+
+  it('names the profile that was saved elsewhere', () => {
+    const scope = {
+      principalType: 'role',
+      principalId: 'USER',
+      name: 'USER',
+    } as t.ConfigScope;
+    render(
+      <ChangeReview
+        review={reviewFor([{ fieldPath: 'registration.socialLogins', value: ['openid'] }], {
+          conflict: true,
+          scope,
+        })}
+      />,
+    );
+    expect(screen.getByRole('alert')).toHaveTextContent(/USER was saved elsewhere/);
+  });
+
   it('shows list changes as added and removed items', () => {
     render(
       <ChangeReview

src/components/configuration/review/ChangeReview.tsx

@@ -87,15 +87,59 @@ function SaveFailureAction({ review }: { review: t.ChangeReviewState }) {
   return null;
 }
 
+/**
+ * A save that found the target saved elsewhere meanwhile (nothing was
+ * written; the page already shows what is stored now): reload, dropping the
+ * edits, or merge them over it.
+ */
+function ConflictNotice({ review }: { review: t.ChangeReviewState }) {
+  const localize = useLocalize();
+  return (
+    <div
+      role="alert"
+      className="flex flex-col gap-2 rounded-lg bg-(--cui-color-feedback-warning-bg) px-3 py-2 text-(--cui-color-feedback-warning-fg)"
+    >
+      <p className="m-0 flex items-center gap-1.5 text-sm font-medium">
+        <Icon name="warning" size="xs" aria-hidden="true" />
+        {localize('com_config_conflict_title')}
+      </p>
+      <p className="m-0 text-xs">
+        {localize('com_config_conflict_body', {
+          target: review.scope
+            ? `${scopeTypeLabel(review.scope, localize)}: ${review.scope.name}`
+            : localize('com_scope_base_config'),
+        })}
+      </p>
+      <div className="flex flex-wrap justify-end gap-2">
+        <Button
+          htmlType="button"
+          type="secondary"
+          label={localize('com_config_conflict_reload')}
+          onClick={review.reloadLatest}
+          disabled={review.saving}
+        />
+        <Button
+          htmlType="button"
+          type="primary"
+          label={localize('com_config_conflict_merge')}
+          onClick={() => void review.mergeLatest()}
+          disabled={review.saving || review.blocked}
+        />
+      </div>
+    </div>
+  );
+}
+
 /**
  * The change review drawer (WS7): what Save writes to the open target,
  * grouped tab › section › entry, with BEFORE → AFTER, the value a reset
  * reverts to, masked secrets, warnings and problems. Save stays disabled
- * while pre-flight problems exist.
+ * while pre-flight problems exist, and after a conflict, which the notice's
+ * Reload or Merge and save resolves.
  */
 export function ChangeReview({ review }: t.ChangeReviewProps) {
   const localize = useLocalize();
-  const { model, open, saving, blocked } = review;
+  const { model, open, saving, blocked, conflict } = review;
   const blocking = model.issues.filter((issue) => issue.blocking);
   const isEmpty = model.count === 0;
   const returnFocus = useReturnFocus(open, activeConfigTab);
@@ -148,6 +192,7 @@ export function ChangeReview({ review }: t.ChangeReviewProps) {
           </header>
 
           <div className="flex min-h-0 flex-1 flex-col gap-4 overflow-y-auto px-4 py-3">
+            {conflict && <ConflictNotice review={review} />}
             {blocking.length > 0 && (
               <IssueList
                 title={localize('com_config_review_issues', { count: blocking.length })}
@@ -206,7 +251,7 @@ export function ChangeReview({ review }: t.ChangeReviewProps) {
                 saving ? localize('com_config_review_saving') : localize('com_config_review_save')
               }
               onClick={() => void review.confirm()}
-              disabled={saving || blocked}
+              disabled={saving || blocked || conflict}
             />
           </footer>
         </Dialog.Content>

src/constants/contract.ts

@@ -52,6 +52,15 @@ export const BUNDLED_CONFIG_LIMITS: t.ConfigLimits = {
   overrideCacheTtlMs: 60_000,
 };
 
+/** `expectedRevision` that makes a write apply only when the principal has no document. */
+export const ABSENT_REVISION = 'absent';
+
+/** The admin API's code for a write whose `expectedRevision` no longer matches (409). */
+export const VERSION_CONFLICT_CODE = 'CONFIG_VERSION_CONFLICT';
+
+/** A save refused before anything is written: one section holds more changes than one batch takes (`maxChangeOps`). */
+export const TOO_MANY_CHANGES_CODE = 'TOO_MANY_CHANGES';
+
 /** A stdio MCP server's process fields: only librechat.yaml sets them (D10). */
 export const PROCESS_MCP_FIELDS: readonly string[] = ['command', 'args', 'env', 'cwd', 'stderr'];
 

src/hooks/config/layers.ts

@@ -196,6 +196,7 @@ export function useConfigLayers({
     overridePaths: isEditingScope ? scopeOverridePaths : dbOverridePaths,
     listOverrideCounts,
     valueLayers,
+    targetRevision: isEditingScope ? scopeData?.revision : baseConfigData?.dbRevision,
   };
 }