vitepress/docs/en/reference/runtime-api.md

Runtime API

VitePress offers several built-in APIs to let you access app data. VitePress also comes with a few built-in components that can be used globally.

The helper methods are globally importable from vitepress and are typically used in custom theme Vue components. However, they are also usable inside .md pages because markdown files are compiled into Vue Single-File Components.

Methods that start with use* indicates that it is a Vue 3 Composition API function ("Composable") that can only be used inside setup() or <script setup>.

useData

Returns page-specific data. The returned object has the following type:

interface VitePressData<T = any> {
  /**
   * Site-level metadata
   */
  site: Ref<SiteData<T>>
  /**
   * themeConfig from .vitepress/config.js
   */
  theme: Ref<T>
  /**
   * Page-level metadata
   */
  page: Ref<PageData>
  /**
   * Page frontmatter
   */
  frontmatter: Ref<PageData['frontmatter']>
  /**
   * Dynamic route params
   */
  params: Ref<PageData['params']>
  title: Ref<string>
  description: Ref<string>
  lang: Ref<string>
  isDark: Ref<boolean>
  dir: Ref<string>
  localeIndex: Ref<string>
  /**
   * Current location hash
   */
  hash: Ref<string>
}

interface PageData {
  title: string
  titleTemplate?: string | boolean
  description: string
  relativePath: string
  filePath: string,
  headers: Header[]
  frontmatter: Record<string, any>
  params?: Record<string, any>
  isNotFound?: boolean
  lastUpdated?: number
}

Example:

<script setup>
import { useData } from 'vitepress'

const { theme } = useData()
</script>

<template>
  <h1>{{ theme.footer.copyright }}</h1>
</template>

useRoute

Returns the current route object with the following type:

interface Route {
  path: string
  data: PageData
  component: Component | null
}

useRouter

Returns the VitePress router instance so you can programmatically navigate to another page.

interface Router {
  /**
   * Current route.
   */
  route: Route
  /**
   * Navigate to a new URL.
   */
  go: (to?: string) => Promise<void>
  /**
   * Called before the route changes. Return `false` to cancel the navigation.
   */
  onBeforeRouteChange?: (to: string) => Awaitable<void | boolean>
  /**
   * Called before the page component is loaded (after the history state is
   * updated). Return `false` to cancel the navigation.
   */
  onBeforePageLoad?: (to: string) => Awaitable<void | boolean>
  /**
   * Called after the page component is loaded (before the page component is updated).
   */
  onAfterPageLoad?: (to: string) => Awaitable<void>
  /**
   * Called after the route changes.
   */
  onAfterRouteChanged?: (to: string) => Awaitable<void>
}

withBase

• Type: (path: string) => string

Appends the configured base to a given URL path. Also see Base URL.

<Content />

The <Content /> component displays the rendered markdown contents. Useful when creating your own theme.

<template>
  <h1>Custom Layout!</h1>
  <Content />
</template>

<ClientOnly />

The <ClientOnly /> component renders its slot only at client side.

Because VitePress applications are server-rendered in Node.js when generating static builds, any Vue usage must conform to the universal code requirements. In short, make sure to only access Browser / DOM APIs in beforeMount or mounted hooks.

If you are using or demoing components that are not SSR-friendly (for example, contain custom directives), you can wrap them inside the ClientOnly component.

<ClientOnly>
  <NonSSRFriendlyComponent />
</ClientOnly>

• Related: SSR Compatibility

$frontmatter

Directly access current page's frontmatter data in Vue expressions.

---
title: Hello
---

# {{ $frontmatter.title }}

$params

Directly access current page's dynamic route params in Vue expressions.

- package name: {{ $params.pkg }}
- version: {{ $params.version }}