diff --git a/cli/src/generate.ts b/cli/src/generate.ts
index ab566d9e..34fe594c 100644
--- a/cli/src/generate.ts
+++ b/cli/src/generate.ts
@@ -8,7 +8,11 @@ import { createPackageJson } from './packageJson.js'
 import { createRender } from './render.js'
 import { getTemplate, readFiles, readJsonFile, writeFiles } from './utils/index.js'
 
-export async function generate(mode: Mode, data: ResolvedData, cwd = process.cwd()): Promise<void> {
+export async function generate(
+  mode: Mode,
+  data: ResolvedData,
+  cwd: string = process.cwd(),
+): Promise<void> {
   let userPkg: Record<string, any> = {}
   if (mode === Mode.init) {
     const pkgPath = path.join(cwd, 'package.json')
diff --git a/cli/src/run.ts b/cli/src/run.ts
index 17b5e8e8..92d11818 100644
--- a/cli/src/run.ts
+++ b/cli/src/run.ts
@@ -11,7 +11,7 @@ import { prompt } from './prompt.js'
 import { t } from './translate.js'
 import { getPackageManager } from './utils/index.js'
 
-export async function run(mode: Mode, root?: string) {
+export async function run(mode: Mode, root?: string): Promise<void> {
   intro(colors.cyan('Welcome to VuePress and vuepress-theme-plume !'))
 
   const result = await prompt(mode, root)
diff --git a/cli/src/translate.ts b/cli/src/translate.ts
index 9fdf0aa4..dfa0fd18 100644
--- a/cli/src/translate.ts
+++ b/cli/src/translate.ts
@@ -1,15 +1,23 @@
 import type { Langs, Locale } from './types.js'
 import { locales } from './locales/index.js'
 
-function createTranslate(lang?: Langs) {
+interface Translate {
+  setLang: (lang: Langs) => void
+  t: (key: keyof Locale) => string
+}
+
+function createTranslate(lang?: Langs): Translate {
   let current: Langs = lang || 'en-US'
 
   return {
-    setLang: (lang: Langs) => {
+    setLang: (lang) => {
       current = lang
     },
-    t: (key: keyof Locale) => locales[current][key],
+    t: key => locales[current][key],
   }
 }
 
-export const { t, setLang } = createTranslate()
+const translate = createTranslate()
+
+export const t: Translate['t'] = translate.t
+export const setLang: Translate['setLang'] = translate.setLang
diff --git a/cli/src/utils/fs.ts b/cli/src/utils/fs.ts
index dd8d0dde..0be5b96a 100644
--- a/cli/src/utils/fs.ts
+++ b/cli/src/utils/fs.ts
@@ -22,7 +22,7 @@ export async function writeFiles(
   files: File[],
   target: string,
   rewrite?: (path: string) => string,
-) {
+): Promise<void> {
   for (const { filepath, content } of files) {
     let root = path.join(target, filepath).replace(/\.handlebars$/, '')
     if (rewrite)
diff --git a/cli/src/utils/index.ts b/cli/src/utils/index.ts
index badbda4a..d28afa05 100644
--- a/cli/src/utils/index.ts
+++ b/cli/src/utils/index.ts
@@ -1,11 +1,11 @@
 import path from 'node:path'
 import { fileURLToPath } from 'node:url'
 
-export const __dirname = path.dirname(fileURLToPath(import.meta.url))
+export const __dirname: string = path.dirname(fileURLToPath(import.meta.url))
 
-export const resolve = (...args: string[]) => path.resolve(__dirname, '../', ...args)
+export const resolve = (...args: string[]): string => path.resolve(__dirname, '../', ...args)
 
-export const getTemplate = (dir: string) => resolve('templates', dir)
+export const getTemplate = (dir: string): string => resolve('templates', dir)
 
 export * from './fs.js'
 export * from './getPackageManager.js'
diff --git a/docs/.vuepress/client.ts b/docs/.vuepress/client.ts
index 1aa5976f..a24581b2 100644
--- a/docs/.vuepress/client.ts
+++ b/docs/.vuepress/client.ts
@@ -1,3 +1,4 @@
+import type { ClientConfig } from 'vuepress/client'
 import { h } from 'vue'
 import { Layout } from 'vuepress-theme-plume/client'
 import { defineClientConfig } from 'vuepress/client'
@@ -13,4 +14,4 @@ export default defineClientConfig({
       'aside-outline-after': () => h(AsideNav),
     }),
   },
-})
+}) as ClientConfig
diff --git a/docs/.vuepress/config.ts b/docs/.vuepress/config.ts
index 27eb67a4..ab981aa6 100644
--- a/docs/.vuepress/config.ts
+++ b/docs/.vuepress/config.ts
@@ -1,3 +1,4 @@
+import type { UserConfig } from 'vuepress'
 import fs from 'node:fs'
 import path from 'node:path'
 import { viteBundler } from '@vuepress/bundler-vite'
@@ -48,4 +49,4 @@ export default defineUserConfig({
   shouldPrefetch: false,
 
   theme,
-})
+}) as UserConfig
diff --git a/docs/.vuepress/navbar.ts b/docs/.vuepress/navbar.ts
index 61175400..0c310390 100644
--- a/docs/.vuepress/navbar.ts
+++ b/docs/.vuepress/navbar.ts
@@ -1,7 +1,8 @@
+import type { ThemeNavItem } from 'vuepress-theme-plume'
 import { defineNavbarConfig } from 'vuepress-theme-plume'
 import { version } from '../../package.json'
 
-export const zhNavbar = defineNavbarConfig([
+export const zhNavbar: ThemeNavItem[] = defineNavbarConfig([
   {
     text: '指南',
     icon: 'icon-park-outline:guide-board',
@@ -54,7 +55,7 @@ export const zhNavbar = defineNavbarConfig([
   },
 ])
 
-export const enNavbar = defineNavbarConfig([
+export const enNavbar: ThemeNavItem[] = defineNavbarConfig([
   {
     text: 'Guide',
     icon: 'icon-park-outline:guide-board',
diff --git a/docs/.vuepress/notes/en/index.ts b/docs/.vuepress/notes/en/index.ts
index 579c6a81..af7fd886 100644
--- a/docs/.vuepress/notes/en/index.ts
+++ b/docs/.vuepress/notes/en/index.ts
@@ -1,8 +1,9 @@
+import type { ThemeNoteListOptions } from 'vuepress-theme-plume'
 import { defineNotesConfig } from 'vuepress-theme-plume'
 import { themeConfig } from './theme-config'
 import { themeGuide } from './theme-guide'
 
-export const enNotes = defineNotesConfig({
+export const enNotes: ThemeNoteListOptions = defineNotesConfig({
   dir: 'en/notes',
   link: '/',
   notes: [
diff --git a/docs/.vuepress/notes/en/theme-config.ts b/docs/.vuepress/notes/en/theme-config.ts
index a28c4599..0f34ec4f 100644
--- a/docs/.vuepress/notes/en/theme-config.ts
+++ b/docs/.vuepress/notes/en/theme-config.ts
@@ -1,6 +1,7 @@
+import type { ThemeNote } from 'vuepress-theme-plume'
 import { defineNoteConfig } from 'vuepress-theme-plume'
 
-export const themeConfig = defineNoteConfig({
+export const themeConfig: ThemeNote = defineNoteConfig({
   dir: 'theme/config',
   link: '/config/',
   sidebar: [
diff --git a/docs/.vuepress/notes/en/theme-guide.ts b/docs/.vuepress/notes/en/theme-guide.ts
index f439b565..91637f65 100644
--- a/docs/.vuepress/notes/en/theme-guide.ts
+++ b/docs/.vuepress/notes/en/theme-guide.ts
@@ -1,6 +1,7 @@
+import type { ThemeNote } from 'vuepress-theme-plume'
 import { defineNoteConfig } from 'vuepress-theme-plume'
 
-export const themeGuide = defineNoteConfig({
+export const themeGuide: ThemeNote = defineNoteConfig({
   dir: 'theme/guide',
   link: '/guide/',
   sidebar: [
diff --git a/docs/.vuepress/notes/zh/index.ts b/docs/.vuepress/notes/zh/index.ts
index 62247b24..4061e77d 100644
--- a/docs/.vuepress/notes/zh/index.ts
+++ b/docs/.vuepress/notes/zh/index.ts
@@ -1,10 +1,11 @@
+import type { ThemeNoteListOptions } from 'vuepress-theme-plume'
 import { defineNotesConfig } from 'vuepress-theme-plume'
 // import { plugins } from './plugins'
 import { themeConfig } from './theme-config'
 import { themeGuide } from './theme-guide'
 import { tools } from './tools'
 
-export const zhNotes = defineNotesConfig({
+export const zhNotes: ThemeNoteListOptions = defineNotesConfig({
   dir: 'notes',
   link: '/',
   notes: [
diff --git a/docs/.vuepress/notes/zh/plugins.ts b/docs/.vuepress/notes/zh/plugins.ts
index 87379775..24d7828c 100644
--- a/docs/.vuepress/notes/zh/plugins.ts
+++ b/docs/.vuepress/notes/zh/plugins.ts
@@ -1,6 +1,7 @@
+import type { ThemeNote } from 'vuepress-theme-plume'
 import { defineNoteConfig } from 'vuepress-theme-plume'
 
-export const plugins = defineNoteConfig({
+export const plugins: ThemeNote = defineNoteConfig({
   dir: 'plugins',
   link: '/plugins/',
   sidebar: [
diff --git a/docs/.vuepress/notes/zh/theme-config.ts b/docs/.vuepress/notes/zh/theme-config.ts
index 514f4ed1..f85b554b 100644
--- a/docs/.vuepress/notes/zh/theme-config.ts
+++ b/docs/.vuepress/notes/zh/theme-config.ts
@@ -1,6 +1,7 @@
+import type { ThemeNote } from 'vuepress-theme-plume'
 import { defineNoteConfig } from 'vuepress-theme-plume'
 
-export const themeConfig = defineNoteConfig({
+export const themeConfig: ThemeNote = defineNoteConfig({
   dir: 'theme/config',
   link: '/config/',
   sidebar: [
diff --git a/docs/.vuepress/notes/zh/theme-guide.ts b/docs/.vuepress/notes/zh/theme-guide.ts
index 70859eea..72363a24 100644
--- a/docs/.vuepress/notes/zh/theme-guide.ts
+++ b/docs/.vuepress/notes/zh/theme-guide.ts
@@ -1,6 +1,7 @@
+import type { ThemeNote } from 'vuepress-theme-plume'
 import { defineNoteConfig } from 'vuepress-theme-plume'
 
-export const themeGuide = defineNoteConfig({
+export const themeGuide: ThemeNote = defineNoteConfig({
   dir: 'theme/guide',
   link: '/guide/',
   sidebar: [
diff --git a/docs/.vuepress/notes/zh/tools.ts b/docs/.vuepress/notes/zh/tools.ts
index 769c3d61..8e1924d3 100644
--- a/docs/.vuepress/notes/zh/tools.ts
+++ b/docs/.vuepress/notes/zh/tools.ts
@@ -1,6 +1,7 @@
+import type { ThemeNote } from 'vuepress-theme-plume'
 import { defineNoteConfig } from 'vuepress-theme-plume'
 
-export const tools = defineNoteConfig({
+export const tools: ThemeNote = defineNoteConfig({
   dir: 'tools',
   link: '/tools/',
   sidebar: [
diff --git a/docs/.vuepress/plume.config.ts b/docs/.vuepress/plume.config.ts
index 8544c7b3..61a1d0ad 100644
--- a/docs/.vuepress/plume.config.ts
+++ b/docs/.vuepress/plume.config.ts
@@ -1,3 +1,4 @@
+import type { ThemeConfig } from 'vuepress-theme-plume'
 import path from 'node:path'
 import { defineThemeConfig } from 'vuepress-theme-plume'
 import { enNavbar, zhNavbar } from './navbar.js'
@@ -49,4 +50,4 @@ export default defineThemeConfig({
     contentFile: path.join(__dirname, 'bulletin.md'),
     enablePage: page => page.path === '/guide/features/bulletin/',
   },
-})
+}) as ThemeConfig
diff --git a/docs/.vuepress/themes/composables/caniuse.ts b/docs/.vuepress/themes/composables/caniuse.ts
index 87481786..8bafff15 100644
--- a/docs/.vuepress/themes/composables/caniuse.ts
+++ b/docs/.vuepress/themes/composables/caniuse.ts
@@ -1,4 +1,4 @@
-import type { Ref } from 'vue'
+import type { ComputedRef, Ref } from 'vue'
 import { onClickOutside, useDebounceFn, useEventListener, useLocalStorage } from '@vueuse/core'
 import { computed, onMounted, readonly, ref, watch } from 'vue'
 
@@ -35,7 +35,14 @@ const embedTypes: SelectItem[] = [
   { label: 'image', value: 'image' },
 ]
 
-export function useCaniuseVersionSelect() {
+export function useCaniuseVersionSelect(): {
+  past: Ref<string>
+  future: Ref<string>
+  embedType: Ref<string>
+  pastList: Readonly<SelectItem[]>
+  futureList: Readonly<SelectItem[]>
+  embedTypeList: Readonly<SelectItem[]>
+} {
   const past = ref('2')
   const future = ref('1')
   const embedType = ref('')
@@ -57,7 +64,12 @@ export function useCaniuseVersionSelect() {
 export function useCaniuseFeaturesSearch(
   inputEl: Ref<HTMLInputElement | null>,
   listEl: Ref<HTMLUListElement | null>,
-) {
+): {
+    featureList: Ref<Feature[] | undefined>
+    isFocus: Ref<boolean>
+    feature: ComputedRef<string>
+    onSelect: (item: Feature) => void
+  } {
   const features = useLocalStorage('plume:caniuse-feature-list', [] as Feature[])
   const featuresUpdated = useLocalStorage('plume:caniuse-feature-list-updated', Date.now())
   const maxAge = 1000 * 60 * 60 * 24 * 3 // 3 days
@@ -104,7 +116,7 @@ export function useCaniuseFeaturesSearch(
     isFocus.value = true
   })
 
-  function onSelect(item: Feature) {
+  function onSelect(item: Feature): void {
     selected.value = item
     isFocus.value = false
     if (inputEl.value)
@@ -124,7 +136,10 @@ export function useCaniuse({ feature, embedType, past, future }: {
   embedType: Ref<string>
   past: Ref<string>
   future: Ref<string>
-}) {
+}): {
+    output: ComputedRef<string>
+    rendered: ComputedRef<string>
+  } {
   const output = computed(() => {
     let content = '@[caniuse'
     if (embedType.value)
diff --git a/docs/.vuepress/themes/composables/theme-colors.ts b/docs/.vuepress/themes/composables/theme-colors.ts
index 95ab7ed4..9201dc60 100644
--- a/docs/.vuepress/themes/composables/theme-colors.ts
+++ b/docs/.vuepress/themes/composables/theme-colors.ts
@@ -2,6 +2,8 @@ import type { InjectionKey, Ref } from 'vue'
 import { useSessionStorage, useStyleTag } from '@vueuse/core'
 import { inject, provide, watch } from 'vue'
 
+declare const __VUEPRESS_DEV__: boolean
+
 export interface ThemeColor {
   name: string
   key: string
@@ -82,14 +84,16 @@ const preset: ThemeColorsGroup[] = [
   },
 ]
 
-const themeColorSymbol: InjectionKey<{
+interface ThemeColorResult {
   lightColors: Ref<ThemeColorsGroup[]>
   darkColors: Ref<ThemeColorsGroup[]>
   css: Ref<string>
   reset: () => void
-}> = Symbol(__VUEPRESS_DEV__ ? 'theme-color' : '')
+}
 
-export function setupThemeColors() {
+const themeColorSymbol: InjectionKey<ThemeColorResult> = Symbol(__VUEPRESS_DEV__ ? 'theme-color' : '')
+
+export function setupThemeColors(): void {
   const lightColors = useSessionStorage<ThemeColorsGroup[]>('custom-theme-colors-light', resolveDefaultColors('light'))
   const darkColors = useSessionStorage<ThemeColorsGroup[]>('custom-theme-colors-dark', resolveDefaultColors('dark'))
 
@@ -138,7 +142,7 @@ function resolveDefaultColors(type: 'light' | 'dark') {
   }))
 }
 
-export function useThemeColors() {
+export function useThemeColors(): ThemeColorResult {
   const result = inject(themeColorSymbol)
 
   if (!result) {
diff --git a/plugins/plugin-fonts/tsup.config.ts b/plugins/plugin-fonts/tsup.config.ts
index 1368098a..e4343cc4 100644
--- a/plugins/plugin-fonts/tsup.config.ts
+++ b/plugins/plugin-fonts/tsup.config.ts
@@ -38,4 +38,4 @@ export default defineConfig(() => {
     ])
   }
   return options
-})
+}) as Options[]
diff --git a/plugins/plugin-md-power/src/client/composables/audio.ts b/plugins/plugin-md-power/src/client/composables/audio.ts
index c2ed9bcd..1fd19b44 100644
--- a/plugins/plugin-md-power/src/client/composables/audio.ts
+++ b/plugins/plugin-md-power/src/client/composables/audio.ts
@@ -1,4 +1,4 @@
-import type { MaybeRef } from 'vue'
+import type { MaybeRef, Ref } from 'vue'
 import { onMounted, onUnmounted, ref, toValue, watch } from 'vue'
 
 const mimeTypes = {
@@ -36,9 +36,23 @@ export interface AudioPlayerOptions {
   onwaiting?: HTMLAudioElement['onwaiting']
 }
 
+interface UseAudioPlayerResult {
+  player: HTMLAudioElement | null
+  isSupported: Ref<boolean>
+  loaded: Ref<boolean>
+  paused: Ref<boolean>
+  currentTime: Ref<number>
+  duration: Ref<number>
+  play: () => void
+  pause: () => void
+  seek: (time: number) => void
+  setVolume: (volume: number) => void
+  destroy: () => void
+}
+
 const playerList: HTMLAudioElement[] = []
 
-export function useAudioPlayer(source: MaybeRef<string>, options: AudioPlayerOptions = {}) {
+export function useAudioPlayer(source: MaybeRef<string>, options: AudioPlayerOptions = {}): UseAudioPlayerResult {
   let player: HTMLAudioElement | null = null
 
   let unknownSupport = false
@@ -194,7 +208,7 @@ export function useAudioPlayer(source: MaybeRef<string>, options: AudioPlayerOpt
     return false
   }
 
-  function destroy() {
+  function destroy(): void {
     player?.pause()
     player?.remove()
     playerList.splice(playerList.indexOf(player!), 1)
diff --git a/plugins/plugin-md-power/src/client/composables/codeRepl.ts b/plugins/plugin-md-power/src/client/composables/codeRepl.ts
index 5cab6db2..6342aec3 100644
--- a/plugins/plugin-md-power/src/client/composables/codeRepl.ts
+++ b/plugins/plugin-md-power/src/client/composables/codeRepl.ts
@@ -38,7 +38,10 @@ export function resolveCode(el: HTMLElement): string {
   return clone.textContent || ''
 }
 
-export function resolveCodeInfo(el: HTMLDivElement) {
+export function resolveCodeInfo(el: HTMLDivElement): {
+  lang: Lang
+  code: string
+} {
   const wrapper = el.querySelector('div[class*=language-]')
   const lang = wrapper?.className.match(RE_LANGUAGE)?.[1]
   const codeEl = wrapper?.querySelector('pre') as HTMLElement
@@ -50,7 +53,20 @@ export function resolveCodeInfo(el: HTMLDivElement) {
   return { lang: resolveLang(lang) as Lang, code }
 }
 
-export function useCodeRepl(el: Ref<HTMLDivElement | null>) {
+interface UseCodeReplResult {
+  lang: Ref<Lang | undefined>
+  loaded: Ref<boolean>
+  firstRun: Ref<boolean>
+  finished: Ref<boolean>
+  stdout: Ref<string[]>
+  stderr: Ref<string[]>
+  error: Ref<string>
+  backendVersion: Ref<string>
+  onCleanRun: () => void
+  onRunCode: () => Promise<void>
+}
+
+export function useCodeRepl(el: Ref<HTMLDivElement | null>): UseCodeReplResult {
   const lang = ref<Lang>()
   const loaded = ref(true)
   const firstRun = ref(true)
@@ -74,7 +90,7 @@ export function useCodeRepl(el: Ref<HTMLDivElement | null>) {
     rust: executeRust,
   }
 
-  function onCleanRun() {
+  function onCleanRun(): void {
     loaded.value = false
     finished.value = false
     stdout.value = []
@@ -84,7 +100,7 @@ export function useCodeRepl(el: Ref<HTMLDivElement | null>) {
     backendVersion.value = ''
   }
 
-  async function onRunCode() {
+  async function onRunCode(): Promise<void> {
     if (!el.value || !loaded.value)
       return
     const info = resolveCodeInfo(el.value)
diff --git a/plugins/plugin-md-power/src/client/composables/demo.ts b/plugins/plugin-md-power/src/client/composables/demo.ts
index 1a887c5d..ea376082 100644
--- a/plugins/plugin-md-power/src/client/composables/demo.ts
+++ b/plugins/plugin-md-power/src/client/composables/demo.ts
@@ -1,4 +1,4 @@
-import type { MaybeRefOrGetter, ShallowRef } from 'vue'
+import type { ComputedRef, MaybeRefOrGetter, Ref, ShallowRef } from 'vue'
 import { onClickOutside, useEventListener } from '@vueuse/core'
 import { computed, getCurrentInstance, onMounted, ref, toValue, useId, watch } from 'vue'
 import { isPlainObject } from 'vuepress/shared'
@@ -11,7 +11,7 @@ export interface DemoConfig {
   cssLib: string[]
 }
 
-export function useExpand(defaultExpand = true) {
+export function useExpand(defaultExpand = true): readonly [Ref<boolean>, () => void] {
   const expanded = ref(defaultExpand)
   function toggle() {
     expanded.value = !expanded.value
@@ -19,11 +19,24 @@ export function useExpand(defaultExpand = true) {
   return [expanded, toggle] as const
 }
 
-export function useResources(el: ShallowRef<HTMLDivElement | null>, config: MaybeRefOrGetter<DemoConfig | undefined>) {
-  const resources = computed<{
-    name: string
-    items: { name: string, url: string }[]
-  }[]>(() => {
+interface ResourceItem {
+  name: string
+  items: SubResourceItem[]
+}
+
+interface SubResourceItem {
+  name: string
+  url: string
+}
+
+interface UseResourcesResult {
+  resources: ComputedRef<ResourceItem[]>
+  showResources: Ref<boolean>
+  toggleResources: () => void
+}
+
+export function useResources(el: ShallowRef<HTMLDivElement | null>, config: MaybeRefOrGetter<DemoConfig | undefined>): UseResourcesResult {
+  const resources = computed<ResourceItem[]>(() => {
     const conf = toValue(config)
     if (!conf)
       return []
@@ -39,7 +52,7 @@ export function useResources(el: ShallowRef<HTMLDivElement | null>, config: Mayb
 
   const showResources = ref(false)
 
-  function toggleResources() {
+  function toggleResources(): void {
     showResources.value = !showResources.value
   }
 
@@ -54,14 +67,16 @@ export function useResources(el: ShallowRef<HTMLDivElement | null>, config: Mayb
   }
 }
 
-export function useFence(fence: ShallowRef<HTMLDivElement | null>, config: MaybeRefOrGetter<DemoConfig | undefined>) {
-  const data = ref<{
-    js: string
-    css: string
-    html: string
-    jsType: string
-    cssType: string
-  }>({ js: '', css: '', html: '', jsType: '', cssType: '' })
+interface FenceData {
+  js: string
+  css: string
+  html: string
+  jsType: string
+  cssType: string
+}
+
+export function useFence(fence: ShallowRef<HTMLDivElement | null>, config: MaybeRefOrGetter<DemoConfig | undefined>): Ref<FenceData> {
+  const data = ref<FenceData>({ js: '', css: '', html: '', jsType: '', cssType: '' })
 
   onMounted(() => {
     if (!fence.value)
@@ -93,7 +108,7 @@ export function useNormalDemo(
   draw: ShallowRef<HTMLIFrameElement | null>,
   title: MaybeRefOrGetter<string | undefined>,
   config: MaybeRefOrGetter<DemoConfig | undefined>,
-) {
+): { id: string, height: Ref<string> } {
   const current = getCurrentInstance()
   const id = useId()
   const isDark = computed(() => current?.appContext.config.globalProperties.$isDark.value)
@@ -157,7 +172,7 @@ function createHTMLTemplate(title: string, id: string, config?: DemoConfig): str
 </html>`
 }
 
-export function parseData(data: any) {
+export function parseData(data: any): any {
   try {
     if (typeof data === 'string') {
       return JSON.parse(data)
diff --git a/plugins/plugin-md-power/src/client/composables/rustRepl.ts b/plugins/plugin-md-power/src/client/composables/rustRepl.ts
index 11228dea..2366fe3e 100644
--- a/plugins/plugin-md-power/src/client/composables/rustRepl.ts
+++ b/plugins/plugin-md-power/src/client/composables/rustRepl.ts
@@ -66,7 +66,7 @@ function send(type: string, payload: Record<string, any>, meta: Record<string, a
 export async function rustExecute(
   code: string,
   { onEnd, onError, onStderr, onStdout, onBegin }: RustExecuteOptions,
-) {
+): Promise<void> {
   await connect()
   const meta = { sequenceNumber: uuid++ }
   const payload = {
diff --git a/plugins/plugin-md-power/src/client/options.ts b/plugins/plugin-md-power/src/client/options.ts
index 7b135abd..dd8bcb3e 100644
--- a/plugins/plugin-md-power/src/client/options.ts
+++ b/plugins/plugin-md-power/src/client/options.ts
@@ -5,15 +5,19 @@ declare const __MD_POWER_DASHJS_INSTALLED__: boolean
 declare const __MD_POWER_HLSJS_INSTALLED__: boolean
 declare const __MD_POWER_MPEGTSJS_INSTALLED__: boolean
 
-export const pluginOptions = __MD_POWER_INJECT_OPTIONS__
+export const pluginOptions: MarkdownPowerPluginOptions = __MD_POWER_INJECT_OPTIONS__
 
-export const installed = {
+export const installed: {
+  dashjs: boolean
+  hlsjs: boolean
+  mpegtsjs: boolean
+} = {
   dashjs: __MD_POWER_DASHJS_INSTALLED__,
   hlsjs: __MD_POWER_HLSJS_INSTALLED__,
   mpegtsjs: __MD_POWER_MPEGTSJS_INSTALLED__,
 }
 
-export const ART_PLAYER_SUPPORTED_VIDEO_TYPES = ['mp4', 'mp3', 'webm', 'ogg']
+export const ART_PLAYER_SUPPORTED_VIDEO_TYPES: string[] = ['mp4', 'mp3', 'webm', 'ogg']
 
 if (installed.dashjs) {
   ART_PLAYER_SUPPORTED_VIDEO_TYPES.push('mpd', 'dash')
@@ -27,10 +31,10 @@ if (installed.mpegtsjs) {
   ART_PLAYER_SUPPORTED_VIDEO_TYPES.push('ts', 'flv')
 }
 
-export const INJECT_TIMELINE_KEY = Symbol(
+export const INJECT_TIMELINE_KEY: symbol = Symbol(
   __VUEPRESS_DEV__ ? 'timeline' : '',
 )
 
-export const INJECT_COLLAPSE_KEY = Symbol(
+export const INJECT_COLLAPSE_KEY: symbol = Symbol(
   __VUEPRESS_DEV__ ? 'collapse' : '',
 )
diff --git a/plugins/plugin-md-power/src/node/container/card.ts b/plugins/plugin-md-power/src/node/container/card.ts
index c41b4af0..d3455b50 100644
--- a/plugins/plugin-md-power/src/node/container/card.ts
+++ b/plugins/plugin-md-power/src/node/container/card.ts
@@ -13,7 +13,7 @@ interface CardMasonryAttrs {
   gap?: number
 }
 
-export function cardPlugin(md: Markdown) {
+export function cardPlugin(md: Markdown): void {
   /**
    * ::: card title="xxx" icon="xxx"
    * xxx
diff --git a/plugins/plugin-md-power/src/node/container/codeTree.ts b/plugins/plugin-md-power/src/node/container/codeTree.ts
index 28233cad..9d1a86dd 100644
--- a/plugins/plugin-md-power/src/node/container/codeTree.ts
+++ b/plugins/plugin-md-power/src/node/container/codeTree.ts
@@ -111,7 +111,7 @@ function parseFileNodes(files: string[]): FileTreeNode[] {
   return nodes
 }
 
-export function codeTreePlugin(md: Markdown, app: App, options: CodeTreeOptions = {}) {
+export function codeTreePlugin(md: Markdown, app: App, options: CodeTreeOptions = {}): void {
   const getIcon = (filename: string, type: 'folder' | 'file', mode?: FileTreeIconMode): string => {
     mode ||= options.icon || 'colored'
     if (mode === 'simple')
diff --git a/plugins/plugin-md-power/src/node/container/createContainer.ts b/plugins/plugin-md-power/src/node/container/createContainer.ts
index 6fa2304a..04dc578f 100644
--- a/plugins/plugin-md-power/src/node/container/createContainer.ts
+++ b/plugins/plugin-md-power/src/node/container/createContainer.ts
@@ -15,7 +15,7 @@ export function createContainerPlugin(
   md: Markdown,
   type: string,
   { before, after }: ContainerOptions = {},
-) {
+): void {
   const render: RenderRule = (tokens, index, options, env): string => {
     const token = tokens[index]
     const info = token.info.trim().slice(type.length).trim() || ''
@@ -51,7 +51,7 @@ export function createContainerSyntaxPlugin(
   md: Markdown,
   type: string,
   render?: RenderRule,
-) {
+): void {
   const maker = ':'
   const markerMinLen = 3
 
diff --git a/plugins/plugin-md-power/src/node/container/field.ts b/plugins/plugin-md-power/src/node/container/field.ts
index ada9dd79..05e83163 100644
--- a/plugins/plugin-md-power/src/node/container/field.ts
+++ b/plugins/plugin-md-power/src/node/container/field.ts
@@ -12,7 +12,7 @@ interface FieldAttrs {
   default?: string
 }
 
-export function fieldPlugin(md: Markdown) {
+export function fieldPlugin(md: Markdown): void {
   createContainerPlugin(md, 'field', {
     before: (info) => {
       const { attrs } = resolveAttrs<FieldAttrs>(info)
diff --git a/plugins/plugin-md-power/src/node/container/fileTree.ts b/plugins/plugin-md-power/src/node/container/fileTree.ts
index 8180853c..b3ad34ee 100644
--- a/plugins/plugin-md-power/src/node/container/fileTree.ts
+++ b/plugins/plugin-md-power/src/node/container/fileTree.ts
@@ -94,7 +94,7 @@ export function parseFileTreeNodeInfo(info: string): FileTreeNodeProps {
   return { filename, comment, focus, expanded, type, diff }
 }
 
-export function fileTreePlugin(md: Markdown, options: FileTreeOptions = {}) {
+export function fileTreePlugin(md: Markdown, options: FileTreeOptions = {}): void {
   const getIcon = (filename: string, type: 'folder' | 'file', mode?: FileTreeIconMode): string => {
     mode ||= options.icon || 'colored'
     if (mode === 'simple')
diff --git a/plugins/plugin-md-power/src/node/container/index.ts b/plugins/plugin-md-power/src/node/container/index.ts
index eb7facde..6e70c5c0 100644
--- a/plugins/plugin-md-power/src/node/container/index.ts
+++ b/plugins/plugin-md-power/src/node/container/index.ts
@@ -21,7 +21,7 @@ export async function containerPlugin(
   app: App,
   md: Markdown,
   options: MarkdownPowerPluginOptions,
-) {
+): Promise<void> {
   // ::: left / right / center / justify
   alignPlugin(md)
   // ::: tabs
diff --git a/plugins/plugin-md-power/src/node/container/langRepl.ts b/plugins/plugin-md-power/src/node/container/langRepl.ts
index 8514e115..c77b83e5 100644
--- a/plugins/plugin-md-power/src/node/container/langRepl.ts
+++ b/plugins/plugin-md-power/src/node/container/langRepl.ts
@@ -18,7 +18,7 @@ export async function langReplPlugin(app: App, md: markdownIt, {
   go = false,
   kotlin = false,
   rust = false,
-}: ReplOptions) {
+}: ReplOptions): Promise<void> {
   const container = (lang: string): void => createContainerPlugin(md, `${lang}-repl`, {
     before(info) {
       const { attrs } = resolveAttrs<CodeReplMeta>(info)
diff --git a/plugins/plugin-md-power/src/node/container/steps.ts b/plugins/plugin-md-power/src/node/container/steps.ts
index ef3b8759..112b4383 100644
--- a/plugins/plugin-md-power/src/node/container/steps.ts
+++ b/plugins/plugin-md-power/src/node/container/steps.ts
@@ -10,7 +10,7 @@ import { createContainerPlugin } from './createContainer.js'
  * 3. ...
  * :::
  */
-export function stepsPlugin(md: Markdown) {
+export function stepsPlugin(md: Markdown): void {
   createContainerPlugin(md, 'steps', {
     before: () => '<div class="vp-steps">',
   })
diff --git a/plugins/plugin-md-power/src/node/container/timeline.ts b/plugins/plugin-md-power/src/node/container/timeline.ts
index c0d6d7d2..cc2c8c85 100644
--- a/plugins/plugin-md-power/src/node/container/timeline.ts
+++ b/plugins/plugin-md-power/src/node/container/timeline.ts
@@ -40,7 +40,7 @@ const RE_KEY = /(\w+)=\s*/
 const RE_SEARCH_KEY = /\s+\w+=\s*|$/
 const RE_CLEAN_VALUE = /(?<quote>["'])(.*?)(\k<quote>)/
 
-export function timelinePlugin(md: Markdown) {
+export function timelinePlugin(md: Markdown): void {
   createContainerPlugin(md, 'timeline', {
     before(info, tokens, index) {
       parseTimeline(tokens, index)
diff --git a/plugins/plugin-md-power/src/node/demo/demo.ts b/plugins/plugin-md-power/src/node/demo/demo.ts
index e53e7e41..0d868e19 100644
--- a/plugins/plugin-md-power/src/node/demo/demo.ts
+++ b/plugins/plugin-md-power/src/node/demo/demo.ts
@@ -11,7 +11,7 @@ import { normalContainerRender, normalEmbed } from './normal.js'
 import { normalizeAlias } from './supports/alias.js'
 import { vueContainerRender, vueEmbed } from './vue.js'
 
-export function demoEmbed(app: App, md: Markdown) {
+export function demoEmbed(app: App, md: Markdown): void {
   createEmbedRuleBlock<DemoMeta>(md, {
     type: 'demo',
     syntaxPattern: /^@\[demo(?:\s(vue|normal|markdown))?\s?(.*)\]\((.*)\)/,
@@ -50,7 +50,7 @@ const renderMap: Record<string, DemoContainerRender> = {
   markdown: markdownContainerRender,
 }
 
-export function demoContainer(app: App, md: Markdown) {
+export function demoContainer(app: App, md: Markdown): void {
   let currentRender: DemoContainerRender | undefined
   const render: RenderRule = (
     tokens: Token[],
diff --git a/plugins/plugin-md-power/src/node/demo/index.ts b/plugins/plugin-md-power/src/node/demo/index.ts
index 2acf2c8c..eba10b44 100644
--- a/plugins/plugin-md-power/src/node/demo/index.ts
+++ b/plugins/plugin-md-power/src/node/demo/index.ts
@@ -3,7 +3,7 @@ import type { Markdown } from 'vuepress/markdown'
 import { demoContainer, demoEmbed } from './demo.js'
 import { createDemoRender } from './watcher.js'
 
-export function demoPlugin(app: App, md: Markdown) {
+export function demoPlugin(app: App, md: Markdown): void {
   createDemoRender()
   demoEmbed(app, md)
   demoContainer(app, md)
diff --git a/plugins/plugin-md-power/src/node/demo/normal.ts b/plugins/plugin-md-power/src/node/demo/normal.ts
index 2cc5cc44..70d1d1d3 100644
--- a/plugins/plugin-md-power/src/node/demo/normal.ts
+++ b/plugins/plugin-md-power/src/node/demo/normal.ts
@@ -67,7 +67,7 @@ function codeToHtml(md: Markdown, source: NormalCode, info: string): string {
   return md.render(content, {})
 }
 
-export async function compileCode(code: NormalCode, output: string) {
+export async function compileCode(code: NormalCode, output: string): Promise<void> {
   markDemoRender()
   const res = { jsLib: [], cssLib: [], script: '', css: '', html: '' }
   if (!fs.existsSync(output))
diff --git a/plugins/plugin-md-power/src/node/demo/supports/insertScript.ts b/plugins/plugin-md-power/src/node/demo/supports/insertScript.ts
index 19ad5c0b..4b8efccb 100644
--- a/plugins/plugin-md-power/src/node/demo/supports/insertScript.ts
+++ b/plugins/plugin-md-power/src/node/demo/supports/insertScript.ts
@@ -2,7 +2,7 @@ import type { DemoFile, MarkdownDemoEnv } from '../../../shared/demo.js'
 
 const SCRIPT_RE = /<script.*?>/
 
-export function insertSetupScript({ export: name, path }: DemoFile, env: MarkdownDemoEnv) {
+export function insertSetupScript({ export: name, path }: DemoFile, env: MarkdownDemoEnv): void {
   const imports = `import ${name ? `${name} from ` : ''}'${path}';`
   const scriptSetup = env.sfcBlocks!.scriptSetup ??= {
     type: 'script',
diff --git a/plugins/plugin-md-power/src/node/demo/watcher.ts b/plugins/plugin-md-power/src/node/demo/watcher.ts
index 332c66a4..fb66e943 100644
--- a/plugins/plugin-md-power/src/node/demo/watcher.ts
+++ b/plugins/plugin-md-power/src/node/demo/watcher.ts
@@ -14,13 +14,13 @@ let renderDone: null | ((...args: any[]) => void) = null
 let renderCount = 0
 let renderPromise!: Promise<void>
 
-export function createDemoRender() {
+export function createDemoRender(): void {
   renderPromise = new Promise((resolve) => {
     renderDone = resolve
   })
 }
 
-export async function waitDemoRender() {
+export async function waitDemoRender(): Promise<void> {
   if (renderCount === 0) {
     renderDone?.()
     renderDone = null
@@ -28,11 +28,11 @@ export async function waitDemoRender() {
   await renderPromise
 }
 
-export function markDemoRender() {
+export function markDemoRender(): void {
   renderCount++
 }
 
-export function checkDemoRender() {
+export function checkDemoRender(): void {
   if (renderCount > 0) {
     renderCount--
   }
@@ -47,7 +47,7 @@ let watcher: FSWatcher | null = null
 const tasks: Record<string, string> = {}
 const target = 'md-power/demo/watcher.txt'
 
-export function demoWatcher(app: App, watchers: any[]) {
+export function demoWatcher(app: App, watchers: any[]): void {
   if (!watcher) {
     watcher = watch([], { ignoreInitial: true })
   }
@@ -89,7 +89,7 @@ export function demoWatcher(app: App, watchers: any[]) {
   })
 }
 
-export function addTask(app: App, path: string, output: string) {
+export function addTask(app: App, path: string, output: string): void {
   if (tasks[path])
     return
   tasks[path] = output
diff --git a/plugins/plugin-md-power/src/node/embed/index.ts b/plugins/plugin-md-power/src/node/embed/index.ts
index 59b269ce..a9f3f93d 100644
--- a/plugins/plugin-md-power/src/node/embed/index.ts
+++ b/plugins/plugin-md-power/src/node/embed/index.ts
@@ -11,7 +11,7 @@ import { artPlayerPlugin } from './video/artPlayer.js'
 import { bilibiliPlugin } from './video/bilibili.js'
 import { youtubePlugin } from './video/youtube.js'
 
-export function embedSyntaxPlugin(md: Markdown, options: MarkdownPowerPluginOptions) {
+export function embedSyntaxPlugin(md: Markdown, options: MarkdownPowerPluginOptions): void {
   if (options.caniuse) {
     const caniuse = options.caniuse === true ? {} : options.caniuse
     // @[caniuse](feature_name)
diff --git a/plugins/plugin-md-power/src/node/enhance/imageSize.ts b/plugins/plugin-md-power/src/node/enhance/imageSize.ts
index ab715ae6..41d2f9aa 100644
--- a/plugins/plugin-md-power/src/node/enhance/imageSize.ts
+++ b/plugins/plugin-md-power/src/node/enhance/imageSize.ts
@@ -32,7 +32,7 @@ export async function imageSizePlugin(
   app: App,
   md: Markdown,
   type: boolean | 'local' | 'all' = false,
-) {
+): Promise<void> {
   if (!app.env.isBuild || !type)
     return
 
@@ -159,7 +159,7 @@ function resolveImageUrl(src: string, env: MarkdownEnv, app: App): string {
   return path.resolve(src)
 }
 
-export async function scanRemoteImageSize(app: App) {
+export async function scanRemoteImageSize(app: App): Promise<void> {
   if (!app.env.isBuild)
     return
   const cwd = app.dir.source()
diff --git a/plugins/plugin-md-power/src/node/prepareConfigFile.ts b/plugins/plugin-md-power/src/node/prepareConfigFile.ts
index 77bf767e..9cd0aaf8 100644
--- a/plugins/plugin-md-power/src/node/prepareConfigFile.ts
+++ b/plugins/plugin-md-power/src/node/prepareConfigFile.ts
@@ -10,7 +10,7 @@ const CLIENT_FOLDER = ensureEndingSlash(
   path.resolve(__dirname, '../client'),
 )
 
-export async function prepareConfigFile(app: App, options: MarkdownPowerPluginOptions) {
+export async function prepareConfigFile(app: App, options: MarkdownPowerPluginOptions): Promise<string> {
   const imports = new Set<string>()
   const enhances = new Set<string>()
 
diff --git a/plugins/plugin-md-power/src/node/utils/nanoid.ts b/plugins/plugin-md-power/src/node/utils/nanoid.ts
index 2b647dc9..d177694e 100644
--- a/plugins/plugin-md-power/src/node/utils/nanoid.ts
+++ b/plugins/plugin-md-power/src/node/utils/nanoid.ts
@@ -1,3 +1,3 @@
 import { customAlphabet } from 'nanoid'
 
-export const nanoid = customAlphabet('abcdefghijklmnopqrstuvwxyz', 5)
+export const nanoid: (size?: number) => string = customAlphabet('abcdefghijklmnopqrstuvwxyz', 5)
diff --git a/plugins/plugin-md-power/tsup.config.ts b/plugins/plugin-md-power/tsup.config.ts
index 3a136c85..2371140a 100644
--- a/plugins/plugin-md-power/tsup.config.ts
+++ b/plugins/plugin-md-power/tsup.config.ts
@@ -51,4 +51,4 @@ export default defineConfig(() => {
     }) as Options))
   }
   return options
-})
+}) as Options[]
diff --git a/plugins/plugin-replace-assets/src/constants.ts b/plugins/plugin-replace-assets/src/constants.ts
index 0f12ddb1..2693cdb6 100644
--- a/plugins/plugin-replace-assets/src/constants.ts
+++ b/plugins/plugin-replace-assets/src/constants.ts
@@ -1,6 +1,6 @@
 export const PLUGIN_NAME = 'vuepress-plugin-replace-assets'
 
-export const KNOWN_IMAGE_EXTENSIONS = [
+export const KNOWN_IMAGE_EXTENSIONS: string[] = [
   'png',
   'jpg',
   'jpeg',
@@ -10,7 +10,7 @@ export const KNOWN_IMAGE_EXTENSIONS = [
   'avif',
 ]
 
-export const KNOWN_MEDIA_EXTENSIONS = [
+export const KNOWN_MEDIA_EXTENSIONS: string[] = [
   'mp4',
   'webm',
   'ogg',
@@ -25,7 +25,7 @@ export const KNOWN_MEDIA_EXTENSIONS = [
   'pdf',
 ]
 
-export const KNOWN_ASSET_EXTENSIONS = [
+export const KNOWN_ASSET_EXTENSIONS: string[] = [
   ...KNOWN_IMAGE_EXTENSIONS,
   ...KNOWN_MEDIA_EXTENSIONS,
 ]
diff --git a/plugins/plugin-replace-assets/src/unplugin/index.ts b/plugins/plugin-replace-assets/src/unplugin/index.ts
index a1229091..46974136 100644
--- a/plugins/plugin-replace-assets/src/unplugin/index.ts
+++ b/plugins/plugin-replace-assets/src/unplugin/index.ts
@@ -1,10 +1,18 @@
+import type { VitePlugin, WebpackPluginInstance } from 'unplugin'
+import type { ReplacementRule } from '../options.js'
 import {
   createVitePlugin as _createVitePlugin,
   createWebpackPlugin as _createWebpackPlugin,
+
 } from 'unplugin'
 import { unpluginFactory } from './factory.js'
 
-export const createVitePlugin = () => _createVitePlugin(unpluginFactory)
-export const createWebpackPlugin = () => _createWebpackPlugin(unpluginFactory)
+export const createVitePlugin: () => (
+  options: ReplacementRule[]
+) => VitePlugin<any> | VitePlugin<any>[] = () => _createVitePlugin(unpluginFactory)
+
+export const createWebpackPlugin: () => (
+  options: ReplacementRule[]
+) => WebpackPluginInstance = () => _createWebpackPlugin(unpluginFactory)
 
 export * from './transform.js'
diff --git a/plugins/plugin-replace-assets/src/unplugin/utils.ts b/plugins/plugin-replace-assets/src/unplugin/utils.ts
index aef989db..75c89198 100644
--- a/plugins/plugin-replace-assets/src/unplugin/utils.ts
+++ b/plugins/plugin-replace-assets/src/unplugin/utils.ts
@@ -1,6 +1,6 @@
 import { removeEndingSlash, removeLeadingSlash } from '@vuepress/helper'
 
-export function createAssetPattern(prefix: string) {
+export function createAssetPattern(prefix: string): RegExp {
   const s = `(${prefix}.*?)`
   return new RegExp(
     [
@@ -17,7 +17,7 @@ export function createAssetPattern(prefix: string) {
 
 const htmlLangRE = /\.(?:html|htm)$/
 
-export const isHTMLRequest = (request: string) => htmlLangRE.test(request)
+export const isHTMLRequest = (request: string): boolean => htmlLangRE.test(request)
 
 const nonJsRe = /\.json(?:$|\?)/
 
diff --git a/plugins/plugin-replace-assets/tsup.config.ts b/plugins/plugin-replace-assets/tsup.config.ts
index cf0ae11f..78ec2d27 100644
--- a/plugins/plugin-replace-assets/tsup.config.ts
+++ b/plugins/plugin-replace-assets/tsup.config.ts
@@ -21,4 +21,4 @@ export default defineConfig(() => {
   }
 
   return options
-})
+}) as Options[]
diff --git a/plugins/plugin-search/src/client/composables/locale.ts b/plugins/plugin-search/src/client/composables/locale.ts
index 6bdf7a42..7e13589b 100644
--- a/plugins/plugin-search/src/client/composables/locale.ts
+++ b/plugins/plugin-search/src/client/composables/locale.ts
@@ -1,5 +1,5 @@
-import type { MaybeRef } from 'vue'
-import type { SearchBoxLocales } from '../../shared/index.js'
+import type { ComputedRef, MaybeRef } from 'vue'
+import type { SearchBoxLocales, SearchLocaleOptions } from '../../shared/index.js'
 import { computed, toRef } from 'vue'
 import { useRouteLocale } from 'vuepress/client'
 
@@ -21,7 +21,7 @@ const defaultLocales: SearchBoxLocales = {
   },
 }
 
-export function useLocale(locales: MaybeRef<SearchBoxLocales>) {
+export function useLocale(locales: MaybeRef<SearchBoxLocales>): ComputedRef<Partial<SearchLocaleOptions>> {
   const localesRef = toRef(locales)
   const routeLocale = useRouteLocale()
 
diff --git a/plugins/plugin-search/src/client/composables/searchIndex.ts b/plugins/plugin-search/src/client/composables/searchIndex.ts
index 5b136422..91b77f32 100644
--- a/plugins/plugin-search/src/client/composables/searchIndex.ts
+++ b/plugins/plugin-search/src/client/composables/searchIndex.ts
@@ -1,11 +1,14 @@
+import type { ShallowRef } from 'vue'
 import { searchIndex } from '@internal/minisearchIndex'
 import { shallowRef } from 'vue'
 
 declare const __VUE_HMR_RUNTIME__: Record<string, any>
 
-const searchIndexData = shallowRef(searchIndex)
+type SearchIndexData = Record<string, () => Promise<{ default: string }>>
 
-export function useSearchIndex() {
+const searchIndexData = shallowRef<SearchIndexData>(searchIndex)
+
+export function useSearchIndex(): ShallowRef<SearchIndexData> {
   return searchIndexData
 }
 
diff --git a/plugins/plugin-search/src/node/prepareSearchIndex.ts b/plugins/plugin-search/src/node/prepareSearchIndex.ts
index 10ae1414..02372aac 100644
--- a/plugins/plugin-search/src/node/prepareSearchIndex.ts
+++ b/plugins/plugin-search/src/node/prepareSearchIndex.ts
@@ -47,7 +47,7 @@ export async function prepareSearchIndex({
   app,
   isSearchable,
   searchOptions,
-}: SearchIndexOptions) {
+}: SearchIndexOptions): Promise<void> {
   const start = performance.now()
   const pages = isSearchable ? app.pages.filter(isSearchable) : app.pages
   await pMap(pages, p => indexFile(p, searchOptions), {
@@ -69,7 +69,7 @@ export async function onSearchIndexUpdated(
     isSearchable,
     searchOptions,
   }: SearchIndexOptions,
-) {
+): Promise<void> {
   const pages = isSearchable ? app.pages.filter(isSearchable) : app.pages
   if (pages.some(p => p.filePathRelative?.endsWith(filepath))) {
     await indexFile(app.pages.find(p => p.filePathRelative?.endsWith(filepath))!, searchOptions)
@@ -84,7 +84,7 @@ export async function onSearchIndexRemoved(
     isSearchable,
     searchOptions,
   }: SearchIndexOptions,
-) {
+): Promise<void> {
   const pages = isSearchable ? app.pages.filter(isSearchable) : app.pages
   if (pages.some(p => p.filePathRelative?.endsWith(filepath))) {
     const page = app.pages.find(p => p.filePathRelative?.endsWith(filepath))!
diff --git a/plugins/plugin-search/tsup.config.ts b/plugins/plugin-search/tsup.config.ts
index a7f4c1c7..229a41eb 100644
--- a/plugins/plugin-search/tsup.config.ts
+++ b/plugins/plugin-search/tsup.config.ts
@@ -78,4 +78,4 @@ export default defineConfig(() => {
   }
 
   return options
-})
+}) as Options[]
diff --git a/theme/src/client/components/Blog/VPCategoriesGroup.vue b/theme/src/client/components/Blog/VPCategoriesGroup.vue
index 3cb9a77b..0f5c3e2f 100644
--- a/theme/src/client/components/Blog/VPCategoriesGroup.vue
+++ b/theme/src/client/components/Blog/VPCategoriesGroup.vue
@@ -1,12 +1,12 @@
 <script setup lang="ts">
-import type { BlogCategoryItem } from '../../composables/index.js'
+import type { CategoryItem } from '../../composables/index.js'
 import VPCategories from '@theme/Blog/VPCategories.vue'
 import { computed, onMounted, ref, watch } from 'vue'
 import { useRoute } from 'vuepress/client'
 import { useData } from '../../composables/index.js'
 
 const props = withDefaults(defineProps<{
-  item: BlogCategoryItem
+  item: CategoryItem
   depth?: number
 }>(), {
   depth: 0,
@@ -42,7 +42,7 @@ watch(
   { immediate: true },
 )
 
-function hasExpand(item: BlogCategoryItem, id: string) {
+function hasExpand(item: CategoryItem, id: string) {
   return item.id === id
     || item.items.filter(item => item.type === 'category').some(item => hasExpand(item, id))
 }
diff --git a/theme/src/client/components/VPImage.vue b/theme/src/client/components/VPImage.vue
index 9c396a6e..ead3f860 100644
--- a/theme/src/client/components/VPImage.vue
+++ b/theme/src/client/components/VPImage.vue
@@ -25,7 +25,7 @@ const styles = computed(() => {
 <script lang="ts">
 export default {
   inheritAttrs: false,
-}
+} as { inheritAttrs: boolean }
 </script>
 
 <template>
diff --git a/theme/src/client/composables/aside.ts b/theme/src/client/composables/aside.ts
index 8dcfc910..5fec9933 100644
--- a/theme/src/client/composables/aside.ts
+++ b/theme/src/client/composables/aside.ts
@@ -1,8 +1,11 @@
+import type { ComputedRef } from 'vue'
 import { useMediaQuery } from '@vueuse/core'
 import { computed } from 'vue'
 import { useSidebar } from './sidebar.js'
 
-export function useAside() {
+export function useAside(): {
+  isAsideEnabled: ComputedRef<boolean>
+} {
   const { hasSidebar } = useSidebar()
   const is960 = useMediaQuery('(min-width: 960px)')
   const is1280 = useMediaQuery('(min-width: 1280px)')
diff --git a/theme/src/client/composables/blog-archives.ts b/theme/src/client/composables/blog-archives.ts
index 7891c875..2d9dc3c2 100644
--- a/theme/src/client/composables/blog-archives.ts
+++ b/theme/src/client/composables/blog-archives.ts
@@ -1,3 +1,4 @@
+import type { ComputedRef } from 'vue'
 import type { ThemeBlogPostItem } from '../../shared/index.js'
 import { computed } from 'vue'
 import { useLocalePostList } from './blog-data.js'
@@ -6,12 +7,18 @@ import { useThemeData } from './theme-data.js'
 
 export type ShortPostItem = Pick<ThemeBlogPostItem, 'title' | 'path' | 'createTime'>
 
-export function useArchives() {
+interface ArchiveItem {
+  title: string
+  label: string
+  list: ShortPostItem[]
+}
+
+export function useArchives(): { archives: ComputedRef<ArchiveItem[]> } {
   const themeData = useThemeData()
   const list = useLocalePostList()
   const { theme } = useData()
 
-  const archives = computed(() => {
+  const archives = computed<ArchiveItem[]>(() => {
     const archives: { title: string, label: string, list: ShortPostItem[] }[] = []
     const countLocale = theme.value.archiveTotalText || themeData.value.archiveTotalText
 
diff --git a/theme/src/client/composables/blog-category.ts b/theme/src/client/composables/blog-category.ts
index 0978c01c..4e7ad8d9 100644
--- a/theme/src/client/composables/blog-category.ts
+++ b/theme/src/client/composables/blog-category.ts
@@ -1,3 +1,4 @@
+import type { ComputedRef } from 'vue'
 import { computed } from 'vue'
 import { useLocalePostList } from './blog-data.js'
 
@@ -17,10 +18,10 @@ export interface CategoryItem {
 
 export type BlogCategory = (CategoryItem | CategoryItemWithPost)[]
 
-export function useBlogCategory() {
+export function useBlogCategory(): { categories: ComputedRef<BlogCategory> } {
   const postList = useLocalePostList()
 
-  const categories = computed(() => {
+  const categories = computed<BlogCategory>(() => {
     const list: BlogCategory = []
 
     postList.value.forEach((item) => {
diff --git a/theme/src/client/composables/blog-data.ts b/theme/src/client/composables/blog-data.ts
index b8ce6ecf..1d19b535 100644
--- a/theme/src/client/composables/blog-data.ts
+++ b/theme/src/client/composables/blog-data.ts
@@ -1,4 +1,4 @@
-import type { Ref } from 'vue'
+import type { ComputedRef, Ref } from 'vue'
 import type { ThemeBlogPostList } from '../../shared/index.js'
 import {
   blogPostData as blogPostDataRaw,
@@ -14,7 +14,7 @@ export function usePostList(): BlogDataRef {
   return blogPostData as BlogDataRef
 }
 
-export function useLocalePostList() {
+export function useLocalePostList(): ComputedRef<ThemeBlogPostList> {
   const locale = usePageLang()
   return computed(() => blogPostData.value.filter(item => item.lang === locale.value))
 }
diff --git a/theme/src/client/composables/blog-extract.ts b/theme/src/client/composables/blog-extract.ts
index 823c8c72..63d628e4 100644
--- a/theme/src/client/composables/blog-extract.ts
+++ b/theme/src/client/composables/blog-extract.ts
@@ -1,3 +1,4 @@
+import type { ComputedRef } from 'vue'
 import type { BlogCategory } from './blog-category.js'
 import { computed } from 'vue'
 import { useBlogCategory } from './blog-category.js'
@@ -6,32 +7,43 @@ import { useTags } from './blog-tags.js'
 import { useData } from './data.js'
 import { useInternalLink } from './internal-link.js'
 
-export function useBlogExtract() {
+interface BlogExtractLink {
+  link?: string
+  text?: string
+  total: number
+}
+
+export function useBlogExtract(): {
+  hasBlogExtract: ComputedRef<boolean>
+  tags: ComputedRef<BlogExtractLink>
+  archives: ComputedRef<BlogExtractLink>
+  categories: ComputedRef<BlogExtractLink>
+} {
   const { blog } = useData()
   const postList = useLocalePostList()
   const { tags: tagsList } = useTags()
   const { categories: categoryList } = useBlogCategory()
   const links = useInternalLink()
 
-  const hasBlogExtract = computed(() =>
+  const hasBlogExtract = computed<boolean>(() =>
     blog.value.archives !== false
     || blog.value.tags !== false
     || blog.value.categories !== false,
   )
 
-  const tags = computed(() => ({
+  const tags = computed<BlogExtractLink>(() => ({
     link: links.tags.value?.link,
     text: links.tags.value?.text,
     total: tagsList.value.length,
   }))
 
-  const archives = computed(() => ({
+  const archives = computed<BlogExtractLink>(() => ({
     link: links.archive.value?.link,
     text: links.archive.value?.text,
     total: postList.value.length,
   }))
 
-  const categories = computed(() => ({
+  const categories = computed<BlogExtractLink>(() => ({
     link: links.categories.value?.link,
     text: links.categories.value?.text,
     total: getCategoriesTotal(categoryList.value),
diff --git a/theme/src/client/composables/blog-post-list.ts b/theme/src/client/composables/blog-post-list.ts
index 45da1cc0..3da11d98 100644
--- a/theme/src/client/composables/blog-post-list.ts
+++ b/theme/src/client/composables/blog-post-list.ts
@@ -1,4 +1,4 @@
-import type { Ref } from 'vue'
+import type { ComputedRef, Ref } from 'vue'
 import type { ThemeBlogPostItem } from '../../shared/index.js'
 import { useMediaQuery } from '@vueuse/core'
 import { computed } from 'vue'
@@ -8,7 +8,21 @@ import { useRouteQuery } from './route-query.js'
 
 const DEFAULT_PER_PAGE = 15
 
-export function usePostListControl(homePage: Ref<boolean>) {
+interface UsePostListControlResult {
+  postList: ComputedRef<ThemeBlogPostItem[]>
+  page: Ref<number>
+  totalPage: ComputedRef<number>
+  pageRange: ComputedRef<{
+    value: number | string
+    more?: true
+  }[]>
+  isLastPage: ComputedRef<boolean>
+  isFirstPage: ComputedRef<boolean>
+  isPaginationEnabled: ComputedRef<boolean>
+  changePage: (page: number) => void
+}
+
+export function usePostListControl(homePage: Ref<boolean>): UsePostListControlResult {
   const { blog } = useData()
 
   const list = useLocalePostList()
@@ -113,7 +127,7 @@ export function usePostListControl(homePage: Ref<boolean>) {
     return range
   })
 
-  const changePage = (current: number) => {
+  const changePage = (current: number): void => {
     if (page.value === current)
       return
     page.value = current
diff --git a/theme/src/client/composables/blog-tags.ts b/theme/src/client/composables/blog-tags.ts
index dbb53419..4eb02039 100644
--- a/theme/src/client/composables/blog-tags.ts
+++ b/theme/src/client/composables/blog-tags.ts
@@ -1,3 +1,4 @@
+import type { ComputedRef, Ref } from 'vue'
 import type { ThemeBlogPostItem } from '../../shared/index.js'
 import { computed } from 'vue'
 import { toArray } from '../utils/index.js'
@@ -8,13 +9,26 @@ import { useTagColors } from './tag-colors.js'
 
 type ShortPostItem = Pick<ThemeBlogPostItem, 'title' | 'path' | 'createTime'>
 
-export function useTags() {
+interface BlogTagItem {
+  name: string
+  count: string | number
+  className: string
+}
+
+interface UseTagsResult {
+  tags: ComputedRef<BlogTagItem[]>
+  currentTag: Ref<string>
+  postList: ComputedRef<ShortPostItem[]>
+  handleTagClick: (tag: string) => void
+}
+
+export function useTags(): UseTagsResult {
   const { blog } = useData()
   const list = useLocalePostList()
 
   const colors = useTagColors()
 
-  const tags = computed(() => {
+  const tags = computed<BlogTagItem[]>(() => {
     const tagTheme = blog.value.tagsTheme ?? 'colored'
 
     const tagMap: Record<string, number> = {}
@@ -53,7 +67,7 @@ export function useTags() {
     }))
   })
 
-  const handleTagClick = (tag: string) => {
+  const handleTagClick = (tag: string): void => {
     currentTag.value = tag
   }
 
diff --git a/theme/src/client/composables/contributors.ts b/theme/src/client/composables/contributors.ts
index e6c7b8ae..69ee3192 100644
--- a/theme/src/client/composables/contributors.ts
+++ b/theme/src/client/composables/contributors.ts
@@ -6,11 +6,13 @@ import { isPlainObject } from 'vuepress/shared'
 import { useData } from '../composables/data.js'
 import { useThemeData } from './theme-data.js'
 
-export function useContributors(): {
+interface useContributorsResult {
   mode: ComputedRef<'inline' | 'block'>
   contributors: ComputedRef<GitContributor[]>
   hasContributors: ComputedRef<boolean>
-} {
+}
+
+export function useContributors(): useContributorsResult {
   const { frontmatter } = useData()
   const list = _useContributors()
 
diff --git a/theme/src/client/composables/copyright.ts b/theme/src/client/composables/copyright.ts
index 8ef8ebd9..3cf5209f 100644
--- a/theme/src/client/composables/copyright.ts
+++ b/theme/src/client/composables/copyright.ts
@@ -1,5 +1,11 @@
 import type { ComputedRef } from 'vue'
-import type { CopyrightFrontmatter, CopyrightLicense, CopyrightOptions, GitContributor, KnownCopyrightLicense } from '../../shared/index.js'
+import type {
+  CopyrightFrontmatter,
+  CopyrightLicense,
+  CopyrightOptions,
+  GitContributor,
+  KnownCopyrightLicense,
+} from '../../shared/index.js'
 import { computed } from 'vue'
 import { useRouteLocale } from 'vuepress/client'
 import { useContributors } from './contributors.js'
@@ -37,7 +43,18 @@ const LICENSE_URL: Record<KnownCopyrightLicense, { url: string, icons: string[]
   },
 }
 
-export function useCopyright(copyright: ComputedRef<CopyrightFrontmatter>) {
+interface useCopyrightResult {
+  license: ComputedRef<License>
+  author: ComputedRef<Exclude<CopyrightFrontmatter['author'], string>>
+  hasCopyright: ComputedRef<boolean>
+  creation: ComputedRef<CopyrightFrontmatter['creation']>
+  creationText: ComputedRef<string>
+  sourceUrl: ComputedRef<string | undefined>
+}
+
+export function useCopyright(
+  copyright: ComputedRef<CopyrightFrontmatter>,
+): useCopyrightResult {
   const { theme } = useData<'post'>()
   const routeLocale = useRouteLocale()
   const { contributors } = useContributors()
diff --git a/theme/src/client/composables/dark-mode.ts b/theme/src/client/composables/dark-mode.ts
index f2c122e9..07daf76c 100644
--- a/theme/src/client/composables/dark-mode.ts
+++ b/theme/src/client/composables/dark-mode.ts
@@ -9,7 +9,7 @@ export const darkModeSymbol: InjectionKey<DarkModeRef> = Symbol(
   __VUEPRESS_DEV__ ? 'darkMode' : '',
 )
 
-export function enableTransitions() {
+export function enableTransitions(): boolean {
   if (typeof document === 'undefined')
     return false
   return 'startViewTransition' in document
diff --git a/theme/src/client/composables/encrypt.ts b/theme/src/client/composables/encrypt.ts
index 88256f57..cd8cdf41 100644
--- a/theme/src/client/composables/encrypt.ts
+++ b/theme/src/client/composables/encrypt.ts
@@ -81,7 +81,7 @@ function toMatch(match: string, pagePath: string, filePathRelative: string | nul
   return pagePath.startsWith(match) || relativePath.startsWith(match)
 }
 
-export function setupEncrypt() {
+export function setupEncrypt(): void {
   const { page } = useData()
   const route = useRoute()
   const encrypt = useEncryptData()
@@ -148,13 +148,16 @@ export function useEncrypt(): Encrypt {
   return result
 }
 
-export function useEncryptCompare() {
+export function useEncryptCompare(): {
+  compareGlobal: (password: string) => Promise<boolean>
+  comparePage: (password: string) => Promise<boolean>
+} {
   const encrypt = useEncryptData()
   const { page } = useData()
   const route = useRoute()
   const { hashList } = useEncrypt()
 
-  async function compareGlobal(password: string) {
+  async function compareGlobal(password: string): Promise<boolean> {
     if (!password)
       return false
 
@@ -168,7 +171,7 @@ export function useEncryptCompare() {
     return false
   }
 
-  async function comparePage(password: string) {
+  async function comparePage(password: string): Promise<boolean> {
     if (!password)
       return false
 
diff --git a/theme/src/client/composables/flyout.ts b/theme/src/client/composables/flyout.ts
index e542d345..8ee7f95e 100644
--- a/theme/src/client/composables/flyout.ts
+++ b/theme/src/client/composables/flyout.ts
@@ -8,12 +8,12 @@ interface UseFlyoutOptions {
   onBlur?: () => void
 }
 
-export const focusedElement = ref<HTMLElement>()
+export const focusedElement: Ref<HTMLElement | undefined> = ref()
 
 let active = false
 let listeners = 0
 
-export function useFlyout(options: UseFlyoutOptions) {
+export function useFlyout(options: UseFlyoutOptions): Readonly<Ref<boolean>> {
   const focus = ref(false)
 
   if (inBrowser) {
diff --git a/theme/src/client/composables/home.ts b/theme/src/client/composables/home.ts
index 708df2e8..e59602b7 100644
--- a/theme/src/client/composables/home.ts
+++ b/theme/src/client/composables/home.ts
@@ -25,7 +25,7 @@ export function useHomeHeroTintPlate(
   canvas: Ref<HTMLCanvasElement | undefined>,
   enable: Ref<boolean>,
   tintPlate: Ref<ThemeHomeHero['tintPlate']>,
-) {
+): void {
   const isDark = useDarkMode()
 
   let ctx: CanvasRenderingContext2D | null = null
diff --git a/theme/src/client/composables/internal-link.ts b/theme/src/client/composables/internal-link.ts
index 27e4912b..7284196d 100644
--- a/theme/src/client/composables/internal-link.ts
+++ b/theme/src/client/composables/internal-link.ts
@@ -1,3 +1,4 @@
+import type { ComputedRef } from 'vue'
 import type { PresetLocale } from '../../shared/index.js'
 import { computed } from 'vue'
 import { useRouteLocale } from 'vuepress/client'
@@ -9,7 +10,13 @@ export interface InternalLink {
   link: string
 }
 
-export function useInternalLink() {
+export function useInternalLink(): {
+  home: ComputedRef<InternalLink>
+  blog: ComputedRef<InternalLink>
+  tags: ComputedRef<InternalLink | undefined>
+  archive: ComputedRef<InternalLink | undefined>
+  categories: ComputedRef<InternalLink | undefined>
+} {
   const { blog, theme } = useData()
   const themeData = useThemeData()
   const routeLocale = useRouteLocale()
diff --git a/theme/src/client/composables/langs.ts b/theme/src/client/composables/langs.ts
index ee165e57..c241173b 100644
--- a/theme/src/client/composables/langs.ts
+++ b/theme/src/client/composables/langs.ts
@@ -1,3 +1,4 @@
+import type { ComputedRef } from 'vue'
 import { computed } from 'vue'
 import { resolveRoute, useRouteLocale } from 'vuepress/client'
 import { removeLeadingSlash } from 'vuepress/shared'
@@ -6,9 +7,23 @@ import { useData } from './data.js'
 import { useBlogPageData } from './page.js'
 import { useThemeData } from './theme-data.js'
 
+interface Lang {
+  label?: string
+  link: string
+}
+
+interface UseLangOptions {
+  removeCurrent?: boolean
+}
+
+interface UseLangResult {
+  localeLinks: ComputedRef<Lang[]>
+  currentLang: ComputedRef<Lang>
+}
+
 export function useLangs({
   removeCurrent = true,
-} = {}) {
+}: UseLangOptions = {}): UseLangResult {
   const theme = useThemeData()
   const { page } = useData()
   const routeLocale = useRouteLocale()
diff --git a/theme/src/client/composables/latest-updated.ts b/theme/src/client/composables/latest-updated.ts
index 18848f3c..755bab70 100644
--- a/theme/src/client/composables/latest-updated.ts
+++ b/theme/src/client/composables/latest-updated.ts
@@ -1,9 +1,14 @@
+import type { ComputedRef, Ref } from 'vue'
 import { computed, onMounted, ref, watchEffect } from 'vue'
 import { usePageLang } from 'vuepress/client'
 import { useData } from './data.js'
 import { useThemeData } from './theme-data.js'
 
-export function useLastUpdated() {
+export function useLastUpdated(): {
+  datetime: Ref<string>
+  isoDatetime: ComputedRef<string | undefined>
+  lastUpdatedText: ComputedRef<string>
+} {
   const { theme, page, frontmatter } = useData()
   const themeData = useThemeData()
   const lang = usePageLang()
diff --git a/theme/src/client/composables/link.ts b/theme/src/client/composables/link.ts
index 0303bfe4..536d97ce 100644
--- a/theme/src/client/composables/link.ts
+++ b/theme/src/client/composables/link.ts
@@ -1,13 +1,18 @@
-import type { MaybeRefOrGetter } from 'vue'
+import type { ComputedRef, MaybeRefOrGetter } from 'vue'
 import { isLinkExternal } from '@vuepress/helper/client'
 import { computed, toValue } from 'vue'
 import { resolveRouteFullPath, useRoute } from 'vuepress/client'
 import { useData } from './data.js'
 
+interface UseLinkResult {
+  isExternal: ComputedRef<boolean>
+  link: ComputedRef<string | undefined>
+}
+
 export function useLink(
   href: MaybeRefOrGetter<string | undefined>,
   target?: MaybeRefOrGetter<string | undefined>,
-) {
+): UseLinkResult {
   const route = useRoute()
   const { page } = useData()
 
diff --git a/theme/src/client/composables/page.ts b/theme/src/client/composables/page.ts
index 9dfe6bb3..208b2fb3 100644
--- a/theme/src/client/composables/page.ts
+++ b/theme/src/client/composables/page.ts
@@ -1,8 +1,12 @@
+import type { ComputedRef } from 'vue'
 import { computed } from 'vue'
 import { usePostList } from './blog-data.js'
 import { useData } from './data.js'
 
-export function useBlogPageData() {
+export function useBlogPageData(): {
+  isBlogPost: ComputedRef<boolean>
+  isBlogLayout: ComputedRef<boolean>
+} {
   const { page } = useData()
   const postList = usePostList()
 
diff --git a/theme/src/client/composables/preset-locales.ts b/theme/src/client/composables/preset-locales.ts
index f14674fe..7b04d91f 100644
--- a/theme/src/client/composables/preset-locales.ts
+++ b/theme/src/client/composables/preset-locales.ts
@@ -1,9 +1,13 @@
 import type { PresetLocale } from '../../shared/index.js'
 
-declare const __PLUME_PRESET_LOCALE__: Record<string, PresetLocale>
+interface PresetLocales {
+  [locale: string]: PresetLocale
+}
 
-export const presetLocales = __PLUME_PRESET_LOCALE__
+declare const __PLUME_PRESET_LOCALE__: PresetLocales
 
-export function getPresetLocaleData(locale: string, name: keyof PresetLocale) {
+export const presetLocales: PresetLocales = __PLUME_PRESET_LOCALE__
+
+export function getPresetLocaleData(locale: string, name: keyof PresetLocale): string {
   return presetLocales[locale]?.[name] || presetLocales['/'][name]
 }
diff --git a/theme/src/client/composables/prev-next.ts b/theme/src/client/composables/prev-next.ts
index 8a7caff7..c31d170c 100644
--- a/theme/src/client/composables/prev-next.ts
+++ b/theme/src/client/composables/prev-next.ts
@@ -1,4 +1,4 @@
-import type { Ref } from 'vue'
+import type { ComputedRef, Ref } from 'vue'
 import type { NavItemWithLink, ThemeBlogPostItem, ThemeSidebarItem } from '../../shared/index.js'
 import { computed } from 'vue'
 import { resolveRouteFullPath, usePageLang, useRoute } from 'vuepress/client'
@@ -9,7 +9,12 @@ import { useData } from './data.js'
 import { useBlogPageData } from './page.js'
 import { useSidebar } from './sidebar.js'
 
-export function usePrevNext() {
+interface UsePrevNextResult {
+  prev: ComputedRef<NavItemWithLink | null>
+  next: ComputedRef<NavItemWithLink | null>
+}
+
+export function usePrevNext(): UsePrevNextResult {
   const route = useRoute()
   const { frontmatter, theme } = useData()
   const { sidebar } = useSidebar()
diff --git a/theme/src/client/composables/scroll-behavior.ts b/theme/src/client/composables/scroll-behavior.ts
index fdfd9aad..cc35e899 100644
--- a/theme/src/client/composables/scroll-behavior.ts
+++ b/theme/src/client/composables/scroll-behavior.ts
@@ -3,7 +3,7 @@ import { nextTick } from 'vue'
 import { inBrowser } from '../utils/index.js'
 import { useScrollPromise } from './scroll-promise.js'
 
-export function enhanceScrollBehavior(router: Router) {
+export function enhanceScrollBehavior(router: Router): void {
   router.options.scrollBehavior = async (to, from, savedPosition) => {
     await useScrollPromise().wait()
     if (savedPosition)
diff --git a/theme/src/client/composables/sidebar.ts b/theme/src/client/composables/sidebar.ts
index a4ed42a3..07441280 100644
--- a/theme/src/client/composables/sidebar.ts
+++ b/theme/src/client/composables/sidebar.ts
@@ -52,7 +52,7 @@ const sidebarSymbol: InjectionKey<Ref<ResolvedSidebarItem[]>> = Symbol(
   __VUEPRESS_DEV__ ? 'sidebar' : '',
 )
 
-export function setupSidebar() {
+export function setupSidebar(): void {
   const { page, frontmatter } = useData()
 
   const routeLocale = useRouteLocale()
diff --git a/theme/src/client/composables/theme-data.ts b/theme/src/client/composables/theme-data.ts
index 20b694bc..60847843 100644
--- a/theme/src/client/composables/theme-data.ts
+++ b/theme/src/client/composables/theme-data.ts
@@ -52,7 +52,7 @@ function resolveThemeLocaleData(theme: ThemeData, routeLocale: RouteLocale): The
   }
 }
 
-export function setupThemeData(app: App) {
+export function setupThemeData(app: App): void {
   // provide theme data & theme locale data
   const themeData = useThemeData()
   const clientData: ClientData
diff --git a/theme/src/client/config.ts b/theme/src/client/config.ts
index 277140e5..771a60ca 100644
--- a/theme/src/client/config.ts
+++ b/theme/src/client/config.ts
@@ -1,3 +1,4 @@
+import type { ClientConfig } from 'vuepress/client'
 import { defineClientConfig } from 'vuepress/client'
 import {
   enhanceScrollBehavior,
@@ -28,4 +29,4 @@ export default defineClientConfig({
     setupWatermark()
   },
   layouts: { Layout, NotFound },
-})
+}) as ClientConfig
diff --git a/theme/src/client/features/composables/github-repo.ts b/theme/src/client/features/composables/github-repo.ts
index f4db3ca7..4addfc9c 100644
--- a/theme/src/client/features/composables/github-repo.ts
+++ b/theme/src/client/features/composables/github-repo.ts
@@ -1,7 +1,12 @@
-import type { MaybeRef } from 'vue'
+import type { MaybeRef, Ref } from 'vue'
 import { useLocalStorage } from '@vueuse/core'
 import { computed, ref, toValue, watch } from 'vue'
 
+interface GithubRepoLicense {
+  name: string
+  url: string
+}
+
 export interface GithubRepoInfo {
   name: string
   fullName: string
@@ -17,10 +22,7 @@ export interface GithubRepoInfo {
   visibility: 'Private' | 'Public' // private, public
   template: boolean
   ownerType: 'User' | 'Organization'
-  license: {
-    name: string
-    url: string
-  } | null
+  license: GithubRepoLicense | null
 }
 
 /**
@@ -32,7 +34,12 @@ const storage = useLocalStorage('__VUEPRESS_GITHUB_REPO__', {} as Record<string,
   updatedAt: number
 }>)
 
-export function useGithubRepo(repo: MaybeRef<string>) {
+interface UseGithubRepoResult {
+  data: Ref<GithubRepoInfo | null>
+  loaded: Ref<boolean>
+}
+
+export function useGithubRepo(repo: MaybeRef<string>): UseGithubRepoResult {
   const repoRef = computed(() => {
     const info = toValue(repo)
     const [owner = '', name = ''] = info.split('/')
diff --git a/theme/src/client/features/composables/npm-badge.ts b/theme/src/client/features/composables/npm-badge.ts
index 585c71eb..b0a52595 100644
--- a/theme/src/client/features/composables/npm-badge.ts
+++ b/theme/src/client/features/composables/npm-badge.ts
@@ -81,7 +81,7 @@ export function useNpmBadge(opt: Ref<NpmBadgeOptions>): ComputedRef<NpmBadgeInfo
   })
 }
 
-export function useNpmBadgeGroup(opt: Ref<NpmBadgeGroupOptions>) {
+export function useNpmBadgeGroup(opt: Ref<NpmBadgeGroupOptions>): void {
   const baseOptions = computed<NpmBadgeBaseOptions>(() => {
     const o = toValue(opt)
     return {
diff --git a/theme/src/client/globalComponents.ts b/theme/src/client/globalComponents.ts
index 08fbe254..14a2475a 100644
--- a/theme/src/client/globalComponents.ts
+++ b/theme/src/client/globalComponents.ts
@@ -11,7 +11,7 @@ import VPIcon from '@theme/VPIcon.vue'
 import { hasGlobalComponent } from '@vuepress/helper/client'
 import { h, resolveComponent } from 'vue'
 
-export function globalComponents(app: App) {
+export function globalComponents(app: App): void {
   app.component('Badge', VPBadge)
   app.component('VPBadge', VPBadge)
 
diff --git a/theme/src/client/utils/shared.ts b/theme/src/client/utils/shared.ts
index 0dfa5d96..0766fb82 100644
--- a/theme/src/client/utils/shared.ts
+++ b/theme/src/client/utils/shared.ts
@@ -1,9 +1,9 @@
-export const EXTERNAL_URL_RE = /^[a-z]+:/i
-export const PATHNAME_PROTOCOL_RE = /^pathname:\/\//
-export const HASH_RE = /#.*$/
-export const EXT_RE = /(index|README)?\.(md|html)$/
+export const EXTERNAL_URL_RE: RegExp = /^[a-z]+:/i
+export const PATHNAME_PROTOCOL_RE: RegExp = /^pathname:\/\//
+export const HASH_RE: RegExp = /#.*$/
+export const EXT_RE: RegExp = /(index|README)?\.(md|html)$/
 
-export const inBrowser = typeof document !== 'undefined'
+export const inBrowser: boolean = typeof document !== 'undefined'
 
 export function toArray<T>(value: T | T[]): T[] {
   return Array.isArray(value) ? value : [value]
diff --git a/theme/src/node/autoFrontmatter/generator.ts b/theme/src/node/autoFrontmatter/generator.ts
index 482cd68b..a785c386 100644
--- a/theme/src/node/autoFrontmatter/generator.ts
+++ b/theme/src/node/autoFrontmatter/generator.ts
@@ -32,7 +32,7 @@ export interface Generate {
 
 let generate: Generate | null = null
 
-export function initAutoFrontmatter() {
+export function initAutoFrontmatter(): void {
   const { autoFrontmatter = {}, ...options } = getThemeConfig()
   if (autoFrontmatter === false)
     return
@@ -86,7 +86,7 @@ export function initAutoFrontmatter() {
   }
 }
 
-export async function generateAutoFrontmatter(app: App) {
+export async function generateAutoFrontmatter(app: App): Promise<void> {
   perf.mark('generate:frontmatter')
   if (!generate)
     return
@@ -111,7 +111,7 @@ export async function generateAutoFrontmatter(app: App) {
   perf.log('generate:frontmatter')
 }
 
-export async function watchAutoFrontmatter(app: App, watchers: any[]) {
+export async function watchAutoFrontmatter(app: App, watchers: any[]): Promise<void> {
   if (!generate)
     return
 
diff --git a/theme/src/node/autoFrontmatter/resolveLinkBySidebar.ts b/theme/src/node/autoFrontmatter/resolveLinkBySidebar.ts
index 20fe229d..2b0bf089 100644
--- a/theme/src/node/autoFrontmatter/resolveLinkBySidebar.ts
+++ b/theme/src/node/autoFrontmatter/resolveLinkBySidebar.ts
@@ -4,7 +4,7 @@ import { pathJoin } from '../utils/index.js'
 export function resolveLinkBySidebar(
   sidebar: 'auto' | (string | ThemeSidebarItem)[],
   _prefix: string,
-) {
+): Record<string, string> {
   const res: Record<string, string> = {}
 
   if (sidebar === 'auto') {
diff --git a/theme/src/node/config/resolveNotesOptions.ts b/theme/src/node/config/resolveNotesOptions.ts
index 145cc1b1..e7e3a9ba 100644
--- a/theme/src/node/config/resolveNotesOptions.ts
+++ b/theme/src/node/config/resolveNotesOptions.ts
@@ -3,7 +3,7 @@ import { uniq } from '@pengzhanbo/utils'
 import { entries, removeLeadingSlash } from '@vuepress/helper'
 import { normalizePath, withBase } from '../utils/index.js'
 
-export function resolveNotesLinkList(options: ThemeOptions) {
+export function resolveNotesLinkList(options: ThemeOptions): string[] {
   const locales = options.locales || {}
   const notesLinks: string[] = []
   for (const [locale, opt] of entries(locales)) {
diff --git a/theme/src/node/config/setupAlias.ts b/theme/src/node/config/setupAlias.ts
index 6f16974b..d63bfac2 100644
--- a/theme/src/node/config/setupAlias.ts
+++ b/theme/src/node/config/setupAlias.ts
@@ -1,7 +1,8 @@
+import type { ThemeObject } from 'vuepress'
 import { fs, path } from 'vuepress/utils'
 import { resolve } from '../utils/index.js'
 
-export function setupAlias() {
+export function setupAlias(): ThemeObject['alias'] {
   return {
     ...Object.fromEntries(
       fs.readdirSync(
diff --git a/theme/src/node/config/templateBuildRenderer.ts b/theme/src/node/config/templateBuildRenderer.ts
index ae3a5de6..769688e4 100644
--- a/theme/src/node/config/templateBuildRenderer.ts
+++ b/theme/src/node/config/templateBuildRenderer.ts
@@ -6,7 +6,7 @@ import { getThemePackage } from '../utils/index.js'
 export function templateBuildRenderer(
   template: string,
   context: TemplateRendererContext,
-) {
+): Promise<string> | string {
   const options = getThemeConfig()
   const pkg = getThemePackage()
   template = template
diff --git a/theme/src/node/detector/dependency.ts b/theme/src/node/detector/dependency.ts
index f0a20443..2fbe98a9 100644
--- a/theme/src/node/detector/dependency.ts
+++ b/theme/src/node/detector/dependency.ts
@@ -33,7 +33,7 @@ const t = createTranslate({
  * 部分功能需要手动安装依赖，
  * 检查环境中是否缺少依赖
  */
-export function detectDependencies(options: ThemeOptions, plugins: ThemeBuiltinPlugins) {
+export function detectDependencies(options: ThemeOptions, plugins: ThemeBuiltinPlugins): void {
   const shouldInstall: Record<string, string[]> = {}
 
   const markdown = options.markdown || {}
diff --git a/theme/src/node/detector/options.ts b/theme/src/node/detector/options.ts
index c40acb5f..8416746c 100644
--- a/theme/src/node/detector/options.ts
+++ b/theme/src/node/detector/options.ts
@@ -1,4 +1,4 @@
-import type { ThemeOptions } from '../../shared/index.js'
+import type { ThemeBuiltinPlugins, ThemeOptions } from '../../shared/index.js'
 import { detectDependencies } from './dependency.js'
 import { detectMarkdown } from './markdown.js'
 import { detectPlugins } from './plugins.js'
@@ -10,7 +10,11 @@ export function detectThemeOptions({
   plugins = {},
   configFile,
   ...themeOptions
-}: ThemeOptions) {
+}: ThemeOptions): {
+    configFile: string | undefined
+    plugins: ThemeBuiltinPlugins
+    themeOptions: Omit<ThemeOptions, 'plugins' | 'configFile'>
+  } {
   detectDependencies(themeOptions, plugins)
 
   // detect options
diff --git a/theme/src/node/detector/plugins.ts b/theme/src/node/detector/plugins.ts
index 37d7dc47..0feb4bf3 100644
--- a/theme/src/node/detector/plugins.ts
+++ b/theme/src/node/detector/plugins.ts
@@ -8,7 +8,7 @@ const t = createTranslate({
   zh: { message: '{{ plugins }} 不支持以下字段: {{ unsupported }}, 请检查你的配置。' },
 })
 
-export function detectPlugins(plugins: ThemeBuiltinPlugins) {
+export function detectPlugins(plugins: ThemeBuiltinPlugins): void {
   // 部分用户可能混淆 plugins 选项与 vuepress 的 plugins 选项，误传入插件数组
   if (Array.isArray(plugins)) {
     logger.warn(`${colors.green('plugins')} only accept object config, please check your config.`)
diff --git a/theme/src/node/detector/versions.ts b/theme/src/node/detector/versions.ts
index 0d9e9daa..6c0fd8ab 100644
--- a/theme/src/node/detector/versions.ts
+++ b/theme/src/node/detector/versions.ts
@@ -16,7 +16,7 @@ const t = createTranslate({
   },
 })
 
-export function detectVersions(app: App) {
+export function detectVersions(app: App): void {
   detectVuepressVersion()
   detectThemeVersion(app)
 }
diff --git a/theme/src/node/loadConfig/loader.ts b/theme/src/node/loadConfig/loader.ts
index 2cf8564b..14f86996 100644
--- a/theme/src/node/loadConfig/loader.ts
+++ b/theme/src/node/loadConfig/loader.ts
@@ -33,7 +33,7 @@ let loader: Loader | null = null
 export async function initConfigLoader(
   app: App,
   { configFile, onChange, defaultConfig }: InitConfigLoaderOptions,
-) {
+): Promise<void> {
   perf.mark('load-config')
   loader = {
     configFile,
@@ -68,7 +68,7 @@ export async function initConfigLoader(
   perf.log('load-config')
 }
 
-export function watchConfigFile(app: App, watchers: any[], onChange: ChangeEvent) {
+export function watchConfigFile(app: App, watchers: any[], onChange: ChangeEvent): void {
   if (!loader || !loader.configFile)
     return
 
@@ -100,7 +100,7 @@ export function watchConfigFile(app: App, watchers: any[], onChange: ChangeEvent
   watchers.push(watcher)
 }
 
-export async function onConfigChange(onChange: ChangeEvent) {
+export async function onConfigChange(onChange: ChangeEvent): Promise<void> {
   if (loader && !loader.changeEvents.includes(onChange)) {
     loader.changeEvents.push(onChange)
     if (loader.loaded) {
@@ -109,7 +109,7 @@ export async function onConfigChange(onChange: ChangeEvent) {
   }
 }
 
-export function waitForConfigLoaded() {
+export function waitForConfigLoaded(): Promise<ThemeOptions> {
   return new Promise<ThemeOptions>((resolve) => {
     if (loader?.loaded) {
       resolve(loader.config)
@@ -120,7 +120,7 @@ export function waitForConfigLoaded() {
   })
 }
 
-export function getThemeConfig() {
+export function getThemeConfig(): ThemeOptions {
   return loader!.config
 }
 
diff --git a/theme/src/node/pages/autoCategory.ts b/theme/src/node/pages/autoCategory.ts
index bd2dac16..bbf46774 100644
--- a/theme/src/node/pages/autoCategory.ts
+++ b/theme/src/node/pages/autoCategory.ts
@@ -13,7 +13,7 @@ let LOCALE_RE: RegExp
 export function autoCategory(
   page: Page<ThemePageData>,
   options: ThemeOptions,
-) {
+): void {
   const pagePath = page.filePathRelative
   const blog = isPlainObject(options.blog) ? options.blog : {}
   const enabled = blog.categories !== false
diff --git a/theme/src/node/pages/createPages.ts b/theme/src/node/pages/createPages.ts
index 05e77f0b..8328e391 100644
--- a/theme/src/node/pages/createPages.ts
+++ b/theme/src/node/pages/createPages.ts
@@ -13,7 +13,7 @@ function getRootLang(app: App): string {
   return app.siteData.lang
 }
 
-export async function createPages(app: App) {
+export async function createPages(app: App): Promise<void> {
   const options = getThemeConfig()
 
   if (options.blog === false)
diff --git a/theme/src/node/pages/extendsPage.ts b/theme/src/node/pages/extendsPage.ts
index 780acbc3..17a74fb0 100644
--- a/theme/src/node/pages/extendsPage.ts
+++ b/theme/src/node/pages/extendsPage.ts
@@ -6,7 +6,7 @@ import { enableBulletin } from './pageBulletin.js'
 
 export function extendsPageData(
   page: Page<ThemePageData>,
-) {
+): void {
   const options = getThemeConfig()
   cleanPageData(page)
   autoCategory(page, options)
diff --git a/theme/src/node/pages/pageBulletin.ts b/theme/src/node/pages/pageBulletin.ts
index c953b4da..71da0e60 100644
--- a/theme/src/node/pages/pageBulletin.ts
+++ b/theme/src/node/pages/pageBulletin.ts
@@ -5,7 +5,7 @@ import { isFunction, isPlainObject } from '@vuepress/helper'
 export function enableBulletin(
   page: Page<ThemePageData>,
   options: ThemeOptions,
-) {
+): void {
   if (isPlainObject(options.bulletin)) {
     const enablePage = options.bulletin.enablePage
     page.data.bulletin = (isFunction(enablePage) ? enablePage(page) : enablePage) ?? true
diff --git a/theme/src/node/prepare/prepareEncrypt.ts b/theme/src/node/prepare/prepareEncrypt.ts
index 58d51812..e098e731 100644
--- a/theme/src/node/prepare/prepareEncrypt.ts
+++ b/theme/src/node/prepare/prepareEncrypt.ts
@@ -20,7 +20,7 @@ const separator = ':'
 let contentHash = ''
 let fsCache: FsCache<[string, EncryptConfig]> | null = null
 
-export async function prepareEncrypt(app: App) {
+export async function prepareEncrypt(app: App): Promise<void> {
   perf.mark('prepare:encrypt')
   const { encrypt } = getThemeConfig()
   if (!fsCache && app.env.isDev) {
@@ -72,7 +72,7 @@ function resolveEncrypt(encrypt?: EncryptOptions): EncryptConfig {
   return [encrypt?.global ?? false, separator, admin, keys, rules]
 }
 
-export function isEncryptPage(page: Page<ThemePageData>, encrypt?: EncryptOptions) {
+export function isEncryptPage(page: Page<ThemePageData>, encrypt?: EncryptOptions): boolean {
   if (!encrypt)
     return false
 
diff --git a/theme/src/node/prepare/prepareIcons.ts b/theme/src/node/prepare/prepareIcons.ts
index 5cad39f5..38a15670 100644
--- a/theme/src/node/prepare/prepareIcons.ts
+++ b/theme/src/node/prepare/prepareIcons.ts
@@ -38,7 +38,7 @@ function isIconify(icon: any): icon is string {
   return icon[0] !== '{' && ICONIFY_NAME.test(icon)
 }
 
-export async function prepareIcons(app: App) {
+export async function prepareIcons(app: App): Promise<void> {
   perf.mark('prepare:icons:total')
   const options = getThemeConfig()
   if (!isInstalled) {
diff --git a/theme/src/node/prepare/prepareSidebar.ts b/theme/src/node/prepare/prepareSidebar.ts
index 92faaa0f..493a9f68 100644
--- a/theme/src/node/prepare/prepareSidebar.ts
+++ b/theme/src/node/prepare/prepareSidebar.ts
@@ -16,7 +16,7 @@ import {
 import { getThemeConfig } from '../loadConfig/loader.js'
 import { normalizeLink, perf, resolveContent, writeTemp } from '../utils/index.js'
 
-export async function prepareSidebar(app: App) {
+export async function prepareSidebar(app: App): Promise<void> {
   perf.mark('prepare:sidebar')
   const options = getThemeConfig()
   const sidebar = getAllSidebar(options)
diff --git a/theme/src/node/utils/hash.ts b/theme/src/node/utils/hash.ts
index 8784a3b8..10f714e8 100644
--- a/theme/src/node/utils/hash.ts
+++ b/theme/src/node/utils/hash.ts
@@ -1,6 +1,6 @@
 import { createHash } from 'node:crypto'
 import { customAlphabet } from 'nanoid'
 
-export const hash = (content: string) => createHash('md5').update(content).digest('hex')
+export const hash = (content: string): string => createHash('md5').update(content).digest('hex')
 
-export const nanoid = customAlphabet('0123456789abcdefghijklmnopqrstuvwxyz', 8)
+export const nanoid: (size?: number) => string = customAlphabet('0123456789abcdefghijklmnopqrstuvwxyz', 8)
diff --git a/theme/src/node/utils/logger.ts b/theme/src/node/utils/logger.ts
index 6952eea1..ce772736 100644
--- a/theme/src/node/utils/logger.ts
+++ b/theme/src/node/utils/logger.ts
@@ -2,21 +2,21 @@ import { Logger } from '@vuepress/helper'
 import { colors } from 'vuepress/utils'
 import { THEME_NAME } from './constants.js'
 
-export const logger = new Logger(THEME_NAME)
+export const logger: Logger = new Logger(THEME_NAME)
 
 class Perf {
   isDebug: boolean = false
   collect: Record<string, number> = {}
 
-  init(isDebug = false) {
+  init(isDebug = false): void {
     this.isDebug = isDebug
   }
 
-  mark(mark: string) {
+  mark(mark: string): void {
     this.collect[mark] = performance.now()
   }
 
-  log(mark: string) {
+  log(mark: string): void {
     const startTime = this.collect[mark]
     if (!this.isDebug || !startTime)
       return
@@ -24,4 +24,4 @@ class Perf {
   }
 }
 
-export const perf = new Perf()
+export const perf: Perf = new Perf()
diff --git a/theme/src/node/utils/package.ts b/theme/src/node/utils/package.ts
index 2ea508c2..e0011c31 100644
--- a/theme/src/node/utils/package.ts
+++ b/theme/src/node/utils/package.ts
@@ -11,10 +11,10 @@ export function readJsonFileAsync<T extends Record<string, any> = Record<string,
   return {} as T
 }
 
-export function getPackage() {
+export function getPackage(): Record<string, any> {
   return readJsonFileAsync(path.join(process.cwd(), 'package.json'))
 }
 
-export function getThemePackage() {
+export function getThemePackage(): Record<string, any> {
   return readJsonFileAsync(resolve('../package.json'))
 }
diff --git a/theme/src/node/utils/path.ts b/theme/src/node/utils/path.ts
index 7116c112..ce3d06f2 100644
--- a/theme/src/node/utils/path.ts
+++ b/theme/src/node/utils/path.ts
@@ -3,15 +3,15 @@ import { getDirname, path } from 'vuepress/utils'
 
 const __dirname = getDirname(import.meta.url)
 
-export const resolve = (...args: string[]) => path.resolve(__dirname, '../', ...args)
-export const templates = (url: string) => resolve('../templates', url)
+export const resolve = (...args: string[]): string => path.resolve(__dirname, '../', ...args)
+export const templates = (url: string): string => resolve('../templates', url)
 
 const RE_SLASH = /(\\|\/)+/g
-export function normalizePath(path: string) {
+export function normalizePath(path: string): string {
   return path.replace(RE_SLASH, '/')
 }
 
-export function pathJoin(...args: string[]) {
+export function pathJoin(...args: string[]): string {
   return normalizePath(path.join(...args))
 }
 
@@ -22,7 +22,7 @@ export function normalizeLink(base: string, link = ''): string {
 }
 
 const RE_START_END_SLASH = /^\/|\/$/g
-export function getCurrentDirname(basePath: string | undefined, filepath: string) {
+export function getCurrentDirname(basePath: string | undefined, filepath: string): string {
   const dirList = normalizePath(basePath || path.dirname(filepath))
     .replace(RE_START_END_SLASH, '')
     .split('/')
diff --git a/theme/src/node/utils/translate.ts b/theme/src/node/utils/translate.ts
index 828e4cce..56f14cbe 100644
--- a/theme/src/node/utils/translate.ts
+++ b/theme/src/node/utils/translate.ts
@@ -7,10 +7,11 @@ import { isEmptyObject } from '@pengzhanbo/utils'
 
 type TranslateLang = 'zh' | 'en'
 type TranslateLocale = Record<string, string>
+type TranslateData = Record<string, string>
 
-let lang = 'en'
+let lang: TranslateLang = 'en'
 
-export function setTranslateLang(current: string) {
+export function setTranslateLang(current: string): void {
   if (['zh-CN', 'zh', 'zh-Hans', 'zh-Hant'].includes(current)) {
     lang = 'zh'
   }
@@ -19,13 +20,16 @@ export function setTranslateLang(current: string) {
   }
 }
 
-export function createTranslate<Locale extends TranslateLocale = TranslateLocale>(
+export function createTranslate<
+  Data extends TranslateData = TranslateData,
+  Locale extends TranslateLocale = TranslateLocale,
+>(
   locales: Record<TranslateLang, Locale>,
-) {
-  return function t(key: keyof Locale, data?: Record<string, string>) {
+): (key: keyof Locale, data?: Data) => string {
+  return function t(key, data) {
     const resolved = locales[lang][key]
     if (!resolved)
-      return key
+      return String(key)
     if (data && !isEmptyObject(data)) {
       return resolved.replace(/\{\{\s*(\w+)\s*\}\}/g, (_: string, key: string) => data[key] || _)
     }
diff --git a/theme/tsup.config.ts b/theme/tsup.config.ts
index 16eb1440..bccda52d 100644
--- a/theme/tsup.config.ts
+++ b/theme/tsup.config.ts
@@ -108,4 +108,4 @@ export default defineConfig((cli) => {
     ])
   }
   return options
-})
+}) as Options[]
diff --git a/tsconfig.base.json b/tsconfig.base.json
index 32bfad92..5df9ee8d 100644
--- a/tsconfig.base.json
+++ b/tsconfig.base.json
@@ -8,6 +8,7 @@
     "noImplicitAny": false,
     "noEmitOnError": true,
     "allowSyntheticDefaultImports": true,
+    "isolatedDeclarations": true,
     "skipLibCheck": true
   }
 }