diff --git a/app/components/Header/AuthModal.client.vue b/app/components/Header/AuthModal.client.vue
index d12a8e528..76171a888 100644
--- a/app/components/Header/AuthModal.client.vue
+++ b/app/components/Header/AuthModal.client.vue
@@ -5,6 +5,37 @@ import { authRedirect } from '~/utils/atproto/helpers'
 const handleInput = shallowRef('')
 const route = useRoute()
 const { user, logout } = useAtproto()
+const { settings } = useSettings()
+const colorMode = useColorMode()
+const { setLocale, locales, locale } = useI18n()
+
+//TODO need to check them all and idk if this is the spot for it
+watch(
+  user,
+  async loggedInUser => {
+    if (!loggedInUser) return
+
+    const remote = await $fetch('/api/auth/settings')
+    if (!remote) return
+
+    Object.assign(settings.value, remote)
+
+    // Sync theme with colorMode
+    if (remote.theme) {
+      colorMode.preference = remote.theme
+    }
+
+    // Sync locale if it's valid and different from current
+    if (
+      remote.selectedLocale &&
+      remote.selectedLocale !== locale.value &&
+      locales.value.map(l => l.code).includes(remote.selectedLocale)
+    ) {
+      setLocale(remote.selectedLocale)
+    }
+  },
+  { immediate: true },
+)
 
 // https://atproto.com supports 4 locales as of 2026-02-07
 const { locale } = useI18n()
diff --git a/app/composables/useSettings.ts b/app/composables/useSettings.ts
index 98c313957..80d5fb500 100644
--- a/app/composables/useSettings.ts
+++ b/app/composables/useSettings.ts
@@ -1,35 +1,11 @@
 import type { RemovableRef } from '@vueuse/core'
 import { useLocalStorage } from '@vueuse/core'
 import { ACCENT_COLORS } from '#shared/utils/constants'
-import type { LocaleObject } from '@nuxtjs/i18n'
 import { BACKGROUND_THEMES } from '#shared/utils/constants'
-
-type BackgroundThemeId = keyof typeof BACKGROUND_THEMES
-
-type AccentColorId = keyof typeof ACCENT_COLORS.light
-
-/**
- * Application settings stored in localStorage
- */
-export interface AppSettings {
-  /** Display dates as relative (e.g., "3 days ago") instead of absolute */
-  relativeDates: boolean
-  /** Include @types/* package in install command for packages without built-in types */
-  includeTypesInInstall: boolean
-  /** Accent color theme */
-  accentColorId: AccentColorId | null
-  /** Preferred background shade */
-  preferredBackgroundTheme: BackgroundThemeId | null
-  /** Hide platform-specific packages (e.g., @scope/pkg-linux-x64) from search results */
-  hidePlatformPackages: boolean
-  /** User-selected locale */
-  selectedLocale: LocaleObject['code'] | null
-  sidebar: {
-    collapsed: string[]
-  }
-}
+import type { AccentColorId, BackgroundThemeId, AppSettings } from '#shared/schemas/app-settings'
 
 const DEFAULT_SETTINGS: AppSettings = {
+  theme: 'system',
   relativeDates: false,
   includeTypesInInstall: true,
   accentColorId: null,
@@ -41,6 +17,14 @@ const DEFAULT_SETTINGS: AppSettings = {
   },
 }
 
+export const syncSettings = async (settings: AppSettings) => {
+  // DO some error handling
+  await $fetch('/api/auth/settings', {
+    method: 'POST',
+    body: settings,
+  })
+}
+
 const STORAGE_KEY = 'npmx-settings'
 
 // Shared settings instance (singleton per app)
diff --git a/app/pages/settings.vue b/app/pages/settings.vue
index 33e76be99..5ad5f1c9e 100644
--- a/app/pages/settings.vue
+++ b/app/pages/settings.vue
@@ -1,9 +1,11 @@
 <script setup lang="ts">
 const router = useRouter()
+
 const { settings } = useSettings()
 const { locale, locales, setLocale: setNuxti18nLocale } = useI18n()
 const colorMode = useColorMode()
 const { currentLocaleStatus, isSourceLocale } = useI18nStatus()
+const { user } = useAtproto()
 
 // Escape to go back (but not when focused on form elements or modal is open)
 onKeyStroke(
@@ -33,6 +35,12 @@ defineOgImageComponent('Default', {
   primaryColor: '#60a5fa',
 })
 
+watch(settings.value, async () => {
+  if (!user.value) return
+
+  await syncSettings(settings.value)
+})
+
 const setLocale: typeof setNuxti18nLocale = locale => {
   settings.value.selectedLocale = locale
   return setNuxti18nLocale(locale)
@@ -78,7 +86,6 @@ const setLocale: typeof setNuxti18nLocale = locale => {
               </label>
               <select
                 id="theme-select"
-                :value="colorMode.preference"
                 class="w-full sm:w-auto min-w-48 bg-bg border border-border rounded-md px-3 py-2 text-sm text-fg cursor-pointer duration-200 transition-colors hover:border-fg-subtle"
                 @change="
                   colorMode.preference = ($event.target as HTMLSelectElement).value as
@@ -86,6 +93,7 @@ const setLocale: typeof setNuxti18nLocale = locale => {
                     | 'dark'
                     | 'system'
                 "
+                v-model="settings.theme"
               >
                 <option value="system">
                   {{ $t('settings.theme_system') }}
diff --git a/server/api/auth/settings.get.ts b/server/api/auth/settings.get.ts
new file mode 100644
index 000000000..a1f3fa310
--- /dev/null
+++ b/server/api/auth/settings.get.ts
@@ -0,0 +1,10 @@
+import type { AppSettings } from '#shared/schemas/app-settings'
+
+export default defineEventHandler(async event => {
+  // Current thinking is reads can just be a normal event handler and writes use the oauth
+  const serverSession = await useServerSession(event)
+
+  const storage = useStorage('atproto:generic')
+  const storageKey = `settings:${serverSession.data.public.did}`
+  return storage.getItem<AppSettings>(storageKey)
+})
diff --git a/server/api/auth/settings.post.ts b/server/api/auth/settings.post.ts
new file mode 100644
index 000000000..86ce90954
--- /dev/null
+++ b/server/api/auth/settings.post.ts
@@ -0,0 +1,18 @@
+import * as v from 'valibot'
+import { AppSettingsSchema } from '#shared/schemas/app-settings'
+import type { AppSettings } from '#shared/schemas/app-settings'
+
+export default eventHandlerWithOAuthSession(async (event, oauthSession) => {
+  // TODO: prob find a better spot. Can't be event handler cause i need oauth on session.delete
+  if (oauthSession == undefined) {
+    return createError({
+      statusCode: 401,
+      statusMessage: 'Unauthorized',
+    })
+  }
+  const body = v.parse(AppSettingsSchema, await readBody(event))
+
+  const storage = useStorage('atproto:generic')
+  const storageKey = `settings:${oauthSession.did}`
+  storage.setItem<AppSettings>(storageKey, body)
+})
diff --git a/server/utils/atproto/oauth.ts b/server/utils/atproto/oauth.ts
index c8fc6cd41..83f7b8971 100644
--- a/server/utils/atproto/oauth.ts
+++ b/server/utils/atproto/oauth.ts
@@ -43,12 +43,6 @@ export function getOauthClientMetadata() {
   }) as OAuthClientMetadataInput
 }
 
-type EventHandlerWithOAuthSession<T extends EventHandlerRequest, D> = (
-  event: H3Event<T>,
-  session: OAuthSession | undefined,
-  serverSession: SessionManager,
-) => Promise<D>
-
 async function getOAuthSession(
   event: H3Event,
 ): Promise<{ oauthSession: OAuthSession | undefined; serverSession: SessionManager }> {
@@ -100,11 +94,23 @@ export async function throwOnMissingOAuthScope(oAuthSession: OAuthSession, requi
   }
 }
 
+type EventHandlerWithOAuthSession<T extends EventHandlerRequest, D> = (
+  event: H3Event<T>,
+  session: OAuthSession | undefined,
+  serverSession: SessionManager,
+) => Promise<D>
+
+/**
+ * Handler with a valid OAuth session that is ready to be used
+ * @param handler
+ * @returns
+ */
 export function eventHandlerWithOAuthSession<T extends EventHandlerRequest, D>(
   handler: EventHandlerWithOAuthSession<T, D>,
 ) {
   return defineEventHandler(async event => {
     const { oauthSession, serverSession } = await getOAuthSession(event)
+
     return await handler(event, oauthSession, serverSession)
   })
 }
diff --git a/shared/schemas/app-settings.ts b/shared/schemas/app-settings.ts
new file mode 100644
index 000000000..ba31a0876
--- /dev/null
+++ b/shared/schemas/app-settings.ts
@@ -0,0 +1,28 @@
+import * as v from 'valibot'
+import { ACCENT_COLORS, BACKGROUND_THEMES } from '#shared/utils/constants'
+
+type AccentColorKey = keyof typeof ACCENT_COLORS.light
+type BackgroundThemeKey = keyof typeof BACKGROUND_THEMES
+
+const accentColorIds = Object.keys(ACCENT_COLORS.light) as [AccentColorKey, ...AccentColorKey[]]
+const backgroundThemeIds = Object.keys(BACKGROUND_THEMES) as [
+  BackgroundThemeKey,
+  ...BackgroundThemeKey[],
+]
+
+export const AppSettingsSchema = v.object({
+  theme: v.picklist(['light', 'dark', 'system']),
+  relativeDates: v.boolean(),
+  includeTypesInInstall: v.boolean(),
+  accentColorId: v.nullable(v.picklist(accentColorIds)),
+  preferredBackgroundTheme: v.nullable(v.picklist(backgroundThemeIds)),
+  hidePlatformPackages: v.boolean(),
+  selectedLocale: v.nullable(v.string()),
+  sidebar: v.object({
+    collapsed: v.array(v.string()),
+  }),
+})
+
+export type AppSettings = v.InferOutput<typeof AppSettingsSchema>
+export type AccentColorId = AppSettings['accentColorId']
+export type BackgroundThemeId = AppSettings['preferredBackgroundTheme']