N
Nuxt•4mo ago
lazygopher

Understanding useSession behavior in Nuxt with Better-Auth and NuxtUI

I'm using Better-Auth for authentication and ran into some confusion while trying to implement a simple feature: showing a Login button in the menu when the user is not authenticated, and Sign Out when they are. I'm also using NuxtUI for the UI components. After a lot of trial and error, I got it working with the code below, but I got questions: 1. Why does using await to useSession() fix it? 2. Would it make sense to disable SSR for this component to simplify or optimize things? 
# menu.vue
<script setup lang="ts">
import type { DropdownMenuItem } from "@nuxt/ui"
import { useSession, signOut } from "~/lib/auth-client"
const { data: session } = await useSession(useFetch)
const loggedIn = computed(() => !!session?.value?.user)
const items = computed<DropdownMenuItem[]>(() => {
  const baseItems = [..]
  return loggedIn.value
   ? [
     ...baseItems,
     {
      label: "Sign Out",
      icon: "i-lucide-log-out",
      onSelect: () => {
       signOut(),
       },
      },
     },
    ]
   : [{ label: "Login", icon: "i-lucide-log-in", to: "/login" }, ...baseItems]
})
</script>
<template>
  <UDropdownMenu
   :items="items"
   :content="{
    align: 'start',
    side: 'bottom',
    sideOffset: 8,
   }"
   :ui="{
    content: 'w-48',
   }"
  >
   <UButton icon="i-lucide-menu" color="neutral" variant="outline" />
  </UDropdownMenu>
</template>
# menu.vue
<script setup lang="ts">
import type { DropdownMenuItem } from "@nuxt/ui"
import { useSession, signOut } from "~/lib/auth-client"
const { data: session } = await useSession(useFetch)
const loggedIn = computed(() => !!session?.value?.user)
const items = computed<DropdownMenuItem[]>(() => {
  const baseItems = [..]
  return loggedIn.value
   ? [
     ...baseItems,
     {
      label: "Sign Out",
      icon: "i-lucide-log-out",
      onSelect: () => {
       signOut(),
       },
      },
     },
    ]
   : [{ label: "Login", icon: "i-lucide-log-in", to: "/login" }, ...baseItems]
})
</script>
<template>
  <UDropdownMenu
   :items="items"
   :content="{
    align: 'start',
    side: 'bottom',
    sideOffset: 8,
   }"
   :ui="{
    content: 'w-48',
   }"
  >
   <UButton icon="i-lucide-menu" color="neutral" variant="outline" />
  </UDropdownMenu>
</template>
2 Replies
kapa.ai
kapa.ai•4mo ago
Hi @lazygopher. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave: ---------------------- Let's address your questions based on the available knowledge sources: 1. Why does using await with useSession() fix it? The need to use await with composables like useSession() (or similar session/user composables) often arises from how data fetching and reactivity work in Nuxt, especially when authentication state is involved. In your code, you have: 
const { data: session } = await useSession(useFetch)
const { data: session } = await useSession(useFetch)
This pattern ensures that the session data is resolved before the rest of your setup code runs. If you omit await, you might get a promise or an unresolved state, leading to issues where session.value is undefined or not reactive as expected. This is similar to issues discussed with custom wrappers around useFetch and session composables. If you perform asynchronous operations (like fetching a session or token) before returning reactive data, you must await them to ensure the data is available and reactive in your component. Otherwise, you risk accessing stale or undefined data, or breaking reactivity. This is especially true if your session composable internally performs async operations (like fetching from an API or checking cookies) before exposing the session state. The discussion on wrapping useFetch highlights that using await ensures you get the resolved, reactive data, rather than a pending promise or incomplete state. 2. Would it make sense to disable SSR for this component? Disabling SSR for authentication-dependent UI can sometimes simplify things, especially if your session state is only available client-side (e.g., stored in localStorage, sessionStorage, or via client-only cookies). If you render the menu on the server without access to the user's session, you might show the wrong menu state (e.g., "Login" when the user is actually logged in). Nuxt supports disabling SSR on a per-page or per-component basis. For example, you can use <client-only> to render a component only on the client. This is useful if your authentication/session logic is not available during SSR, or if you want to avoid hydration mismatches. The Nuxt 3 rendering modes video and Nuxt docs on hybrid rendering discuss these strategies. However, disabling SSR means your menu won't be rendered on the server, which could impact SEO or perceived performance. If your session can be reliably determined on the server (e.g., via cookies), it's better to keep SSR enabled for a seamless user experience. If not, wrapping the menu in <client-only> is a practical solution. --- Summary:
- Using await with useSession() ensures you get the resolved, reactive session data, avoiding issues with undefined or stale state, as discussed in the context of useFetch and session composables. - Disabling SSR for the menu component (e.g., using <client-only>) can make sense if your session/auth state is only available client-side, but consider the trade-offs regarding SSR benefits and user experience. If you need more specific guidance for Better-Auth, the knowledge sources do not provide details about that library, so the above is based on general Nuxt and session handling patterns. ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------
kapa.ai
kapa.ai•4mo ago
<@693201794137981049> Kapa.ai is still learning and improving, please let me know how I did by reacting below.

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