diff --git a/packages/ui/src/lib/storage.ts b/packages/ui/src/lib/storage.ts
index 569c4e0e..4616bc94 100644
--- a/packages/ui/src/lib/storage.ts
+++ b/packages/ui/src/lib/storage.ts
@@ -4,7 +4,6 @@ import { serverEvents } from "./server-events"
 import { getLogger } from "./logger"
 
 const log = getLogger("actions")
-const UI_CONFIG_CACHE_KEY = "codenomad:config-owner:ui"
 
 export type OwnerBucket = Record<string, any>
 
@@ -58,23 +57,6 @@ export class ServerStorage {
     })
   }
 
-  readCachedConfigOwner(owner: string): OwnerBucket | undefined {
-    if (owner !== "ui" || typeof window === "undefined" || !window.localStorage) {
-      return undefined
-    }
-
-    try {
-      const raw = window.localStorage.getItem(UI_CONFIG_CACHE_KEY)
-      if (!raw) {
-        return undefined
-      }
-      const parsed = JSON.parse(raw) as OwnerBucket
-      return parsed && typeof parsed === "object" ? parsed : undefined
-    } catch {
-      return undefined
-    }
-  }
-
   async loadConfigOwner(owner: string): Promise<OwnerBucket> {
     const cached = this.configOwnerCache.get(owner)
     if (cached) return cached
@@ -236,9 +218,6 @@ export class ServerStorage {
       return
     }
     cache.set(owner, value)
-    if (kind === "config" && owner === "ui") {
-      this.persistUiConfigCache(value)
-    }
     const bucket = listeners.get(owner)
     if (!bucket) return
     for (const listener of bucket) {
@@ -246,18 +225,6 @@ export class ServerStorage {
     }
   }
 
-  private persistUiConfigCache(value: OwnerBucket) {
-    if (typeof window === "undefined" || !window.localStorage) {
-      return
-    }
-
-    try {
-      window.localStorage.setItem(UI_CONFIG_CACHE_KEY, JSON.stringify(value))
-    } catch {
-      /* noop */
-    }
-  }
-
   private normalizeInstanceData(data?: InstanceData | null): InstanceData {
     const source = data ?? DEFAULT_INSTANCE_DATA
     const messageHistory = Array.isArray(source.messageHistory) ? [...source.messageHistory] : []
diff --git a/packages/ui/src/lib/ui-config-bootstrap-sync.tsx b/packages/ui/src/lib/ui-config-bootstrap-sync.tsx
new file mode 100644
index 00000000..2df1f97e
--- /dev/null
+++ b/packages/ui/src/lib/ui-config-bootstrap-sync.tsx
@@ -0,0 +1,28 @@
+import { createEffect } from "solid-js"
+import { useGlobalCache } from "./hooks/use-global-cache"
+import { useConfig } from "../stores/preferences"
+import type { UiBootstrapConfig } from "./ui-config-bootstrap"
+
+export function UiConfigBootstrapSync() {
+  const { isLoaded, preferences, themePreference } = useConfig()
+  const cache = useGlobalCache({
+    scope: "ui-bootstrap",
+    cacheId: "ui-config",
+    version: "1",
+  })
+
+  createEffect(() => {
+    if (!isLoaded()) {
+      return
+    }
+
+    const next: UiBootstrapConfig = {
+      theme: themePreference(),
+      locale: preferences().locale,
+    }
+
+    cache.set(next)
+  })
+
+  return null
+}
diff --git a/packages/ui/src/lib/ui-config-bootstrap.ts b/packages/ui/src/lib/ui-config-bootstrap.ts
new file mode 100644
index 00000000..e8f483a8
--- /dev/null
+++ b/packages/ui/src/lib/ui-config-bootstrap.ts
@@ -0,0 +1,20 @@
+import { getCacheEntry } from "./global-cache"
+
+export interface UiBootstrapConfig {
+  theme?: "light" | "dark" | "system"
+  locale?: string
+}
+
+const UI_BOOTSTRAP_CACHE_ENTRY = {
+  scope: "ui-bootstrap",
+  cacheId: "ui-config",
+  version: "1",
+} as const
+
+export function readUiBootstrapConfig(): UiBootstrapConfig {
+  return getCacheEntry<UiBootstrapConfig>(UI_BOOTSTRAP_CACHE_ENTRY) ?? {}
+}
+
+export function getUiBootstrapCacheEntry() {
+  return UI_BOOTSTRAP_CACHE_ENTRY
+}
diff --git a/packages/ui/src/main.tsx b/packages/ui/src/main.tsx
index 9fd7c153..72da86dc 100644
--- a/packages/ui/src/main.tsx
+++ b/packages/ui/src/main.tsx
@@ -6,6 +6,8 @@ import { InstanceConfigProvider } from "./stores/instance-config"
 import { runtimeEnv } from "./lib/runtime-env"
 import { I18nProvider, preloadLocaleMessages } from "./lib/i18n"
 import { storage } from "./lib/storage"
+import { readUiBootstrapConfig } from "./lib/ui-config-bootstrap"
+import { UiConfigBootstrapSync } from "./lib/ui-config-bootstrap-sync"
 import "./index.css"
 import "@git-diff-view/solid/styles/diff-view-pure.css"
 
@@ -29,14 +31,26 @@ async function bootstrap() {
     // (and then refine once persisted config loads).
     document.documentElement.removeAttribute("data-theme")
 
-    const cachedUiConfig = storage.readCachedConfigOwner("ui")
-    const theme =
-      cachedUiConfig?.theme === "light" || cachedUiConfig?.theme === "dark" || cachedUiConfig?.theme === "system"
-        ? cachedUiConfig.theme
-        : "system"
-    const locale = typeof cachedUiConfig?.settings?.locale === "string" ? cachedUiConfig.settings.locale : undefined
+    const cachedUiConfig = readUiBootstrapConfig()
+    let theme = cachedUiConfig.theme
+    let locale = cachedUiConfig.locale
 
-    if (theme === "system") {
+    if (theme === undefined || locale === undefined) {
+      try {
+        const uiConfig = await storage.loadConfigOwner("ui")
+        if (theme === undefined) {
+          const nextTheme = (uiConfig as any)?.theme
+          theme = nextTheme === "light" || nextTheme === "dark" || nextTheme === "system" ? nextTheme : undefined
+        }
+        if (locale === undefined) {
+          locale = typeof (uiConfig as any)?.settings?.locale === "string" ? (uiConfig as any).settings.locale : undefined
+        }
+      } catch {
+        // If config fails to load, fall back to CSS defaults.
+      }
+    }
+
+    if (!theme || theme === "system") {
       document.documentElement.removeAttribute("data-theme")
     } else {
       document.documentElement.setAttribute("data-theme", theme)
@@ -48,6 +62,7 @@ async function bootstrap() {
   render(
     () => (
       <ConfigProvider>
+        <UiConfigBootstrapSync />
         <InstanceConfigProvider>
           <I18nProvider>
             <ThemeProvider>