fix(desktop): expose Local / custom endpoint in Providers API-keys tab (#62818)

The onboarding overlay already contains a 'Local / custom endpoint' card
that writes model.provider:custom + base_url + api_key, but no reachable
Desktop GUI path opens it for a fresh add. The composer model pill falls
back to the gateway menu panel (Edit Models…), and Settings → Providers →
API keys is env-var-driven and never lists a custom endpoint — so users
following their instincts cannot add an OpenAI-compatible endpoint (Zyphra,
vLLM, Ollama, …) from the GUI.

Add a 'Local / custom endpoint' row to the API-keys tab that calls
startManualLocalEndpoint(), landing the overlay directly on the existing
custom-endpoint form. Reuses the tested onboarding flow; no new UI surface.

Regression test in providers-settings.test.tsx asserts the row renders and
opens the custom-endpoint flow.

Fixes #62817

Co-authored-by: David Metcalfe <80915+DavidMetcalfe@users.noreply.github.com>

apps/desktop/src/app/settings/providers-settings.test.tsx

@@ -8,6 +8,7 @@ const listOAuthProviders = vi.fn()
 const disconnectOAuthProvider = vi.fn()
 const getEnvVars = vi.fn()
 const startManualProviderOAuth = vi.fn()
+const startManualLocalEndpoint = vi.fn()
 const onboarding = atom({ manual: false })
 
 vi.mock('@/hermes', () => ({
@@ -18,7 +19,8 @@ vi.mock('@/hermes', () => ({
 
 vi.mock('@/store/onboarding', () => ({
   $desktopOnboarding: onboarding,
-  startManualProviderOAuth: (providerId: string) => startManualProviderOAuth(providerId)
+  startManualProviderOAuth: (providerId: string) => startManualProviderOAuth(providerId),
+  startManualLocalEndpoint: (reason: null | string) => startManualLocalEndpoint(reason)
 }))
 
 function provider(id: string, loggedIn: boolean, patch: Partial<OAuthProvider> = {}): OAuthProvider {
@@ -182,4 +184,23 @@ describe('ProvidersSettings', () => {
     })
     expect(await screen.findByText('No providers match your search.')).toBeTruthy()
   })
+
+  it('offers a Local / custom endpoint entry in the API-keys tab that opens the custom-endpoint flow', async () => {
+    // Regression: the composer pill and the providers "have an API key"
+    // affordance both dead-end on the env-var-driven key catalog, which never
+    // lists a custom endpoint — so without this row there is no reachable
+    // Desktop GUI path to add one. See issue #62817.
+    getEnvVars.mockResolvedValue({})
+    listOAuthProviders.mockResolvedValue({ providers: [] })
+
+    const { ProvidersSettings } = await import('./providers-settings')
+    render(<ProvidersSettings onClose={vi.fn()} onViewChange={vi.fn()} view="keys" />)
+
+    const row = await screen.findByText('Local / custom endpoint')
+    expect(screen.getByText(/OpenAI-compatible endpoint/)).toBeTruthy()
+
+    fireEvent.click(row)
+
+    await waitFor(() => expect(startManualLocalEndpoint).toHaveBeenCalledWith(null))
+  })
 })

apps/desktop/src/app/settings/providers-settings.tsx

@@ -21,7 +21,7 @@ import { Check, ChevronDown, ChevronRight, KeyRound, Loader2, Terminal, Trash2 }
 import { normalize } from '@/lib/text'
 import { cn } from '@/lib/utils'
 import { notify, notifyError } from '@/store/notifications'
-import { $desktopOnboarding, startManualProviderOAuth } from '@/store/onboarding'
+import { $desktopOnboarding, startManualLocalEndpoint, startManualProviderOAuth } from '@/store/onboarding'
 import type { EnvVarInfo, OAuthProvider } from '@/types/hermes'
 
 import { isKeyVar, ProviderKeyRows } from './credential-key-ui'
@@ -300,6 +300,36 @@ function NoProviderKeys() {
   )
 }
 
+// Surfaces the "Local / custom endpoint" entry point directly in the API-keys
+// tab so users can add any OpenAI-compatible endpoint (Zyphra, vLLM, Ollama…)
+// from the GUI. The composer pill and the providers "have an API key" affordance
+// both dead-end on the env-var-driven key catalog, which never lists a custom
+// endpoint — so without this row there is no reachable Desktop path to it.
+// The whole row is the button so the click target and a11y focus match the
+// visible area (the chevron + gutter are inside the button, not beside it).
+// Pass reason: null — the onboarding overlay renders an unmapped reason string
+// verbatim as a banner (see ReasonNotice in onboarding/index.tsx), and we don't
+// want a raw identifier like "providers-keys-tab" showing as literal text.
+function LocalEndpointRow({ onOpen }: { onOpen: (reason: null | string) => void }) {
+  const { t } = useI18n()
+  const copy = t.settings.providers.localEndpoint
+
+  return (
+    <RowButton
+      className="group grid grid-cols-[minmax(0,1fr)_auto] items-center gap-1 rounded-[6px] px-3 py-2.5 text-left transition-colors hover:bg-(--ui-control-hover-background)"
+      onClick={() => onOpen(null)}
+    >
+      <div className="flex min-w-0 flex-col gap-0.5">
+        <span className="truncate text-[length:var(--conversation-text-font-size)] font-semibold">{copy.title}</span>
+        <span className="truncate text-[length:var(--conversation-caption-font-size)] leading-5 text-muted-foreground">
+          {copy.description}
+        </span>
+      </div>
+      <ChevronRight className="size-4 text-muted-foreground transition group-hover:text-foreground" />
+    </RowButton>
+  )
+}
+
 export function ProvidersSettings({ onClose, onViewChange, view }: ProvidersSettingsProps) {
   const { t } = useI18n()
   const { rowProps, vars } = useEnvCredentials()
@@ -417,6 +447,7 @@ export function ProvidersSettings({ onClose, onViewChange, view }: ProvidersSett
 
     return (
       <SettingsContent>
+        <LocalEndpointRow onOpen={startManualLocalEndpoint} />
         {keyGroups.length > 0 ? (
           <div className="grid gap-3">
             <SearchField

apps/desktop/src/i18n/en.ts

@@ -766,6 +766,10 @@ export const en: Translations = {
       noProviderKeys: 'No provider API keys available.',
       searchKeys: 'Search providers…',
       noKeysMatch: 'No providers match your search.',
+      localEndpoint: {
+        title: 'Local / custom endpoint',
+        description: 'Point Hermes at any OpenAI-compatible endpoint (Zyphra, vLLM, llama.cpp, Ollama, etc).'
+      },
       loading: 'Loading providers...'
     },
     sessions: {

apps/desktop/src/i18n/ja.ts

@@ -799,6 +799,10 @@ export const ja = defineLocale({
       noProviderKeys: '利用可能なプロバイダー API キーがありません。',
       searchKeys: 'プロバイダーを検索…',
       noKeysMatch: '一致するプロバイダーがありません。',
+      localEndpoint: {
+        title: 'ローカル / カスタムエンドポイント',
+        description: 'OpenAI 互換のエンドポイント（Zyphra、vLLM、llama.cpp、Ollama など）を指定します。'
+      },
       loading: 'プロバイダーを読み込み中...'
     },
     sessions: {

apps/desktop/src/i18n/types.ts

@@ -657,6 +657,10 @@ export interface Translations {
       noProviderKeys: string
       searchKeys: string
       noKeysMatch: string
+      localEndpoint: {
+        title: string
+        description: string
+      }
       loading: string
     }
     sessions: {

apps/desktop/src/i18n/zh-hant.ts

@@ -775,6 +775,10 @@ export const zhHant = defineLocale({
       noProviderKeys: '沒有可用的提供方 API 金鑰。',
       searchKeys: '搜尋提供方…',
       noKeysMatch: '沒有符合的提供方。',
+      localEndpoint: {
+        title: '本地 / 自訂端點',
+        description: '將 Hermes 指向任意 OpenAI 相容端點（Zyphra、vLLM、llama.cpp、Ollama 等）。'
+      },
       loading: '正在載入提供方...'
     },
     sessions: {

apps/desktop/src/i18n/zh.ts

@@ -953,6 +953,10 @@ export const zh: Translations = {
       noProviderKeys: '没有可用的提供方 API 密钥。',
       searchKeys: '搜索提供方…',
       noKeysMatch: '没有匹配的提供方。',
+      localEndpoint: {
+        title: '本地 / 自定义端点',
+        description: '将 Hermes 指向任意 OpenAI 兼容端点（Zyphra、vLLM、llama.cpp、Ollama 等）。'
+      },
       loading: '正在加载提供方...'
     },
     sessions: {