---
category: '@Firebase'
---

# useAuth

Reactive [Firebase Auth](https://firebase.google.com/docs/auth) binding. It provides a reactive `user` and `isAuthenticated` so you
can easily react to changes in the users' authentication status.

## Usage

```vue
<script setup lang="ts">
import { useAuth } from '@vueuse/firebase/useAuth';
import { initializeApp } from 'firebase/app';
import { getAuth, GoogleAuthProvider, signInWithPopup } from 'firebase/auth';

const app = initializeApp({
  /* config */
});
const auth = getAuth(app);
const { isAuthenticated, user } = useAuth(auth);

const signIn = () => signInWithPopup(auth, new GoogleAuthProvider());
</script>

<template>
  <pre v-if="isAuthenticated">{{ user }}</pre>
  <div v-else>
    <button @click="signIn">Sign In with Google</button>
  </div>
</template>
```

## Type Declarations

```ts
export interface UseFirebaseAuthOptions {
  isAuthenticated: ComputedRef<boolean>;
  user: Ref<User | null>;
}
/**
 * Reactive Firebase Auth binding
 *
 * @see https://vueuse.org/useAuth
 *
 * @__NO_SIDE_EFFECTS__
 */
export declare function useAuth(auth: Auth): {
  isAuthenticated: ComputedRef<boolean>;
  user: Ref<
    {
      readonly emailVerified: boolean;
      readonly isAnonymous: boolean;
      readonly metadata: {
        readonly creationTime?: string | undefined;
        readonly lastSignInTime?: string | undefined;
      };
      readonly providerData: {
        readonly displayName: string | null;
        readonly email: string | null;
        readonly phoneNumber: string | null;
        readonly photoURL: string | null;
        readonly providerId: string;
        readonly uid: string;
      }[];
      readonly refreshToken: string;
      readonly tenantId: string | null;
      delete: () => Promise<void>;
      getIdToken: (forceRefresh?: boolean) => Promise<string>;
      getIdTokenResult: (forceRefresh?: boolean) => Promise<IdTokenResult>;
      reload: () => Promise<void>;
      toJSON: () => object;
      readonly displayName: string | null;
      readonly email: string | null;
      readonly phoneNumber: string | null;
      readonly photoURL: string | null;
      readonly providerId: string;
      readonly uid: string;
    } | null,
    | User
    | {
        readonly emailVerified: boolean;
        readonly isAnonymous: boolean;
        readonly metadata: {
          readonly creationTime?: string | undefined;
          readonly lastSignInTime?: string | undefined;
        };
        readonly providerData: {
          readonly displayName: string | null;
          readonly email: string | null;
          readonly phoneNumber: string | null;
          readonly photoURL: string | null;
          readonly providerId: string;
          readonly uid: string;
        }[];
        readonly refreshToken: string;
        readonly tenantId: string | null;
        delete: () => Promise<void>;
        getIdToken: (forceRefresh?: boolean) => Promise<string>;
        getIdTokenResult: (forceRefresh?: boolean) => Promise<IdTokenResult>;
        reload: () => Promise<void>;
        toJSON: () => object;
        readonly displayName: string | null;
        readonly email: string | null;
        readonly phoneNumber: string | null;
        readonly photoURL: string | null;
        readonly providerId: string;
        readonly uid: string;
      }
    | null
  >;
};
```