/pinia

Nuxt Integration

Pinia works seamlessly with Nuxt 3/4, handling SSR, serialization, and XSS protection automatically.

Installation

npx nuxi@latest module add pinia

This installs both @pinia/nuxt and pinia. If pinia isn't installed, add it manually.

npm users: If you get ERESOLVE unable to resolve dependency tree, add to package.json:

"overrides": { "vue": "latest" }

Configuration

// nuxt.config.ts
export default defineNuxtConfig({
  modules: ['@pinia/nuxt'],
})

Auto Imports

These are automatically available:

• usePinia() - get pinia instance
• defineStore() - define stores
• storeToRefs() - extract reactive refs
• acceptHMRUpdate() - HMR support

All stores in app/stores/ (Nuxt 4) or stores/ are auto-imported.

Custom Store Directories

// nuxt.config.ts
export default defineNuxtConfig({
  modules: ['@pinia/nuxt'],
  pinia: {
    storesDirs: ['./stores/**', './custom-folder/stores/**'],
  },
})

Fetching Data in Pages

Use callOnce() for SSR-friendly data fetching:

<script setup>
const store = useStore()

// Run once, data persists across navigations
await callOnce('user', () => store.fetchUser())
</script>

Refetch on Navigation

<script setup>
const store = useStore()

// Refetch on every navigation (like useFetch)
await callOnce('user', () => store.fetchUser(), { mode: 'navigation' })
</script>

Using Stores Outside Components

In navigation guards, middlewares, or other stores, pass the pinia instance:

// middleware/auth.ts
export default defineNuxtRouteMiddleware((to) => {
  const nuxtApp = useNuxtApp()
  const store = useStore(nuxtApp.$pinia)

  if (to.meta.requiresAuth && !store.isLoggedIn) {
    return navigateTo('/login')
  }
})

Most of the time, you don't need this - just use stores in components or other injection-aware contexts.

Pinia Plugins with Nuxt

Create a Nuxt plugin:

// plugins/myPiniaPlugin.ts
import { PiniaPluginContext } from 'pinia'

function MyPiniaPlugin({ store }: PiniaPluginContext) {
  store.$subscribe((mutation) => {
    console.log(`[🍍 ${mutation.storeId}]: ${mutation.type}`)
  })
  return { creationTime: new Date() }
}

export default defineNuxtPlugin(({ $pinia }) => {
  $pinia.use(MyPiniaPlugin)
})