fix(ui): preserve requested provider model aliases

- keep requested=upstream semantics stable in the AI Providers editors

- preview the client-visible ANTHROPIC_MODEL instead of the upstream target

- add UI coverage for alias parsing and formatting helpers

Refs #941

ui/src/components/cliproxy/ai-providers/provider-entry-dialog.tsx

@@ -1,6 +1,10 @@
 import { useMemo, useState } from 'react';
 import { ProviderLogo } from '@/components/cliproxy/provider-logo';
-import { getAiProviderFamilyVisual } from '@/lib/provider-config';
+import {
+  formatRequestedUpstreamModelRules,
+  getAiProviderFamilyVisual,
+  parseRequestedUpstreamModelRules,
+} from '@/lib/provider-config';
 import { Badge } from '@/components/ui/badge';
 import { Button } from '@/components/ui/button';
 import { Collapsible, CollapsibleContent, CollapsibleTrigger } from '@/components/ui/collapsible';
@@ -192,22 +196,7 @@ function parseKeyValueLines(value: string): Array<{ key: string; value: string }
 }
 
 function parseModelAliasLines(value: string) {
-  return value
-    .split('\n')
-    .map((line) => line.trim())
-    .filter((line) => line.length > 0)
-    .map((line) => {
-      const separatorIndex = line.indexOf('=');
-      if (separatorIndex === -1) {
-        return { name: line.trim(), alias: '' };
-      }
-
-      return {
-        name: line.slice(0, separatorIndex).trim(),
-        alias: line.slice(separatorIndex + 1).trim(),
-      };
-    })
-    .filter((item) => item.name.length > 0 || item.alias.length > 0);
+  return parseRequestedUpstreamModelRules(value);
 }
 
 function TextArea({
@@ -241,9 +230,7 @@ function formatExcludedModels(entry?: AiProviderEntryView | null): string {
 }
 
 function formatModelAliases(entry?: AiProviderEntryView | null): string {
-  return (entry?.models || [])
-    .map((item) => (item.alias.trim() ? `${item.name}=${item.alias}` : item.name))
-    .join('\n');
+  return formatRequestedUpstreamModelRules(entry?.models);
 }
 
 function ChecklistCard({

ui/src/lib/provider-config.ts

@@ -9,7 +9,7 @@ import {
   PROVIDER_CAPABILITIES,
   getProvidersByOAuthFlow,
 } from '../../../src/cliproxy/provider-capabilities';
-import type { AiProviderFamilyId } from '../../../src/cliproxy/ai-providers';
+import type { AiProviderFamilyId, AiProviderModelAlias } from '../../../src/cliproxy/ai-providers';
 
 // Monorepo contract: UI consumes provider capability constants directly from backend
 // to enforce one source of truth and prevent provider drift across surfaces.
@@ -115,6 +115,58 @@ export function getAiProviderFamilyVisual(familyId: AiProviderFamilyId): Provide
   }
 }
 
+/**
+ * Parse UI model rules that use the requested=upstream convention into the
+ * provider config shape where `name` is upstream and `alias` is client-visible.
+ */
+export function parseRequestedUpstreamModelRules(value: string): AiProviderModelAlias[] {
+  return value
+    .split('\n')
+    .map((line) => line.trim())
+    .filter((line) => line.length > 0)
+    .map((line) => {
+      const separatorIndex = line.indexOf('=');
+      if (separatorIndex === -1) {
+        return { name: line.trim(), alias: '' };
+      }
+
+      const requested = line.slice(0, separatorIndex).trim();
+      const upstream = line.slice(separatorIndex + 1).trim();
+      if (!upstream) {
+        return { name: requested, alias: '' };
+      }
+
+      return {
+        name: upstream,
+        alias: requested,
+      };
+    })
+    .filter((item) => item.name.length > 0 || item.alias.length > 0);
+}
+
+/**
+ * Format stored provider config back into the UI-facing requested=upstream form.
+ */
+export function formatRequestedUpstreamModelRules(
+  models: AiProviderModelAlias[] | null | undefined
+): string {
+  return (models || [])
+    .map((item) => {
+      const requested = item.alias.trim();
+      const upstream = item.name.trim();
+      return requested ? `${requested}=${upstream}` : upstream;
+    })
+    .join('\n');
+}
+
+/**
+ * Return the client-visible model ID for previews and generated settings.
+ */
+export function getRequestedModelId(model: AiProviderModelAlias): string {
+  const requested = model.alias.trim();
+  return requested || model.name.trim();
+}
+
 export function getProviderLogoAsset(provider: unknown): string | undefined {
   const normalized = normalizeProviderInput(provider);
   if (!isProviderVisualId(normalized)) {

ui/src/pages/cliproxy-ai-providers.tsx

@@ -17,7 +17,12 @@ import { Input } from '@/components/ui/input';
 import { ScrollArea } from '@/components/ui/scroll-area';
 import { Skeleton } from '@/components/ui/skeleton';
 import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs';
-import { getAiProviderFamilyVisual } from '@/lib/provider-config';
+import {
+  formatRequestedUpstreamModelRules,
+  getAiProviderFamilyVisual,
+  getRequestedModelId,
+  parseRequestedUpstreamModelRules,
+} from '@/lib/provider-config';
 import { cn } from '@/lib/utils';
 import { FamilyRail, ProviderEntryDialog } from '@/components/cliproxy/ai-providers';
 import {
@@ -339,22 +344,7 @@ function parseKeyValueLines(value: string): Array<{ key: string; value: string }
 }
 
 function parseModelAliasLines(value: string) {
-  return value
-    .split('\n')
-    .map((line) => line.trim())
-    .filter((line) => line.length > 0)
-    .map((line) => {
-      const separatorIndex = line.indexOf('=');
-      if (separatorIndex === -1) {
-        return { name: line.trim(), alias: '' };
-      }
-
-      return {
-        name: line.slice(0, separatorIndex).trim(),
-        alias: line.slice(separatorIndex + 1).trim(),
-      };
-    })
-    .filter((item) => item.name.length > 0 || item.alias.length > 0);
+  return parseRequestedUpstreamModelRules(value);
 }
 
 function formatHeaders(entry?: AiProviderEntryView | null): string {
@@ -366,9 +356,7 @@ function formatExcludedModels(entry?: AiProviderEntryView | null): string {
 }
 
 function formatModelAliases(entry?: AiProviderEntryView | null): string {
-  return (entry?.models || [])
-    .map((item) => (item.alias.trim() ? `${item.name}=${item.alias}` : item.name))
-    .join('\n');
+  return formatRequestedUpstreamModelRules(entry?.models);
 }
 
 function buildEntryEditorDraft(entry: AiProviderEntryView): EntryEditorDraft {
@@ -579,7 +567,7 @@ function buildSettingsPreview(
     item.name.trim()
   );
   if (primaryModel?.name) {
-    env.ANTHROPIC_MODEL = primaryModel.name;
+    env.ANTHROPIC_MODEL = getRequestedModelId(primaryModel);
   }
 
   return { env };

ui/tests/unit/ui/lib/provider-config.test.ts

@@ -0,0 +1,36 @@
+import { describe, expect, it } from 'vitest';
+
+import {
+  formatRequestedUpstreamModelRules,
+  getRequestedModelId,
+  parseRequestedUpstreamModelRules,
+} from '@/lib/provider-config';
+
+describe('provider model mapping helpers', () => {
+  it('parses requested=upstream rules into stored upstream+alias pairs', () => {
+    expect(
+      parseRequestedUpstreamModelRules('claude-sonnet-4-5=gpt-4.1\nminimax/minimax-m2.7')
+    ).toEqual([
+      { name: 'gpt-4.1', alias: 'claude-sonnet-4-5' },
+      { name: 'minimax/minimax-m2.7', alias: '' },
+    ]);
+  });
+
+  it('formats stored model rules back into requested=upstream text', () => {
+    expect(
+      formatRequestedUpstreamModelRules([
+        { name: 'gpt-4.1', alias: 'claude-sonnet-4-5' },
+        { name: 'minimax/minimax-m2.7', alias: '' },
+      ])
+    ).toBe('claude-sonnet-4-5=gpt-4.1\nminimax/minimax-m2.7');
+  });
+
+  it('prefers the requested alias for generated settings previews', () => {
+    expect(getRequestedModelId({ name: 'gpt-4.1', alias: 'claude-sonnet-4-5' })).toBe(
+      'claude-sonnet-4-5'
+    );
+    expect(getRequestedModelId({ name: 'minimax/minimax-m2.7', alias: '' })).toBe(
+      'minimax/minimax-m2.7'
+    );
+  });
+});