⚡ Auth Store

Access the current user with Svelte stores

SvelteFire

You can skip the code and just install SvelteFire to use this store.

Simple Store

A simple implementation for prototyping

file_type_typescript firebase.ts 
const currentUser = writable<User | null>(null);

onAuthStateChanged(auth, (user) => {
  currentUser.set(user);
});

Custom Store

Full implementation with unsubscribe and SSR support.

file_type_typescript firebase.ts 
/**
 * @returns a store with the current firebase user
 */
function userStore() {
  let unsubscribe: () => void;

  if (!auth || !globalThis.window) {
    console.warn('Auth is not initialized or not in browser');
    const { subscribe } = writable<User | null>(null);
    return {
      subscribe,
    }
  }

  const { subscribe } = writable(auth?.currentUser ?? null, (set) => {
    unsubscribe = onAuthStateChanged(auth, (user) => {
      set(user);
    });

    return () => unsubscribe();
  });

  return {
    subscribe,
  };
}

export const user = userStore();

Signin logic

login/+page.svelte 
<h2>Login</h2>

{#if $user}
  <h2 class="card-title">Welcome, {$user.displayName}</h2>
  <p class="text-center text-success">You are logged in</p>
  <button class="btn btn-warning" on:click={() => signOut(auth)}>Sign out</button>
{:else}
  <button class="btn btn-primary" on:click={signInWithGoogle}>Sign in with Google</button>
{/if}

Svelte 5 Version

{#if $user}
  <h2 class="card-title">Welcome, {$user.displayName}</h2>
  <p class="text-center text-success">You are logged in</p>
  <button class="btn btn-warning" onclick={() => signOut(auth)}>Sign out</button>
{:else}
  <button class="btn btn-primary" onclick={signInWithGoogle}>Sign in with Google</button>
{/if}

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