Svelte Clerk

Community package that integrates Clerk with SvelteKit.

[!IMPORTANT] This package requires Svelte 5 and uses runes and snippets under the hood. If you're using Svelte 4, please refer to clerk-sveltekit.

Installation

npm install svelte-clerk

Set your Clerk API keys

PUBLIC_CLERK_PUBLISHABLE_KEY=pk_test_xxxxxxxx
CLERK_SECRET_KEY=sk_test_xxxxxxx

Configure server handler

This handler will authenticate a token passed from the frontend and attaches the Auth object to event.locals.auth.

// hooks.server.ts
import { withClerkHandler } from 'svelte-clerk/server';

export const handle = withClerkHandler();

Update app.d.ts

Inside your src/ directory, update the app.d.ts file to ensure that the locals added by the Clerk handler are properly typed.

/// <reference types="svelte-clerk/env" />

declare global {
	namespace App {...}
}

Add <ClerkProvider> to your root layout

All Clerk runes and components must be children of the <ClerkProvider> component, which provides active session and user context.

// src/+layout.server.ts
import { buildClerkProps } from 'svelte-clerk/server';

// To enable Clerk SSR support, add initial state props to the load function
export const load = ({ locals }) => {
	return {
		...buildClerkProps(locals.auth)
	};
};

<script lang="ts">
	import type { Snippet } from '@svelte';
	import { ClerkProvider } from 'svelte-clerk';
	import { PUBLIC_CLERK_PUBLISHABLE_KEY } from '$env/static/public';

	const { children }: { children: Snippet } = $props();
</script>

<!-- ... -->

<ClerkProvider publishableKey={PUBLIC_CLERK_PUBLISHABLE_KEY}>
	{@render children()}
</ClerkProvider>

Components

To see all available props for each component, visit the Clerk UI Components docs.

• <ClerkLoaded>
• <ClerkLoading>
• <Protect>
• <SignedIn>
• <SignedOut>
• <SignIn>
• <SignUp>
• <UserButton>
• <UserProfile>
• <OrganizationProfile>
• <OrganizationSwitcher>
• <CreateOrganization>
• <GoogleOneTap>

Runes

• auth - Auth object.
• user - Authenticated user.
• organization - Active Organization of the authenticated user.
• session - Session of the authenticated user.
• clerk - Clerk object.

Example:

The following example demonstrates how to use the auth rune to access the current auth state, like whether the user is signed in or not. It also demonstrates a basic example of how you could use the getToken() method to retrieve a session token for fetching data from an external resource.

<script>
	import { useClerkContext } from 'svelte-clerk';

	// Do not destructure context or you'll lose reactivity!
	const ctx = useClerkContext();
	const userId = $derived(ctx.auth.userId);

	const fetchDataFromExternalResource = async () => {
		const token = await ctx.session.getToken();
		const response = await fetch('https://api.example.com/data', {
			headers: {
				Authorization: `Bearer ${token}`
			}
		});
		return response.json();
	};
</script>

{#if userId === undefined}
	<p>Loading...</p>
{:else if userId === null}
	<p>Sign in to view this page</p>
{:else}
	<div>...</div>
{/if}

Protecting routes

Client side

Clerk offers Control Components that allow you to protect your pages. These components are used to control the visibility of your pages based on the user's authentication state.

<script>
	import { SignedIn, SignedOut, UserButton, SignOutButton } from 'svelte-clerk';
</script>

<div>
	<h1>Index Route</h1>
	<SignedIn>
		<p>You are signed in!</p>
		<div>
			<p>View your profile here 👇</p>
			<UserButton />
		</div>
		<div>
			<SignOutButton />
		</div>
	</SignedIn>
	<SignedOut>
		<p>You are signed out</p>
		<div>
			<a href="/sign-in">Go to Sign in</a>
		</div>
		<div>
			<a href="/sign-up">Go to Sign up</a>
		</div>
	</SignedOut>
</div>

Server side

To protect your routes, you can use the load function to check for the userId singleton. If it doesn't exist, redirect your user back to the sign-in page.

import { redirect } from '@sveltejs/kit';
import { clerkClient } from 'svelte-clerk/server';

export const load = ({ locals }) => {
	const { userId } = locals.auth;

	if (!userId) {
		return redirect(307, '/sign-in');
	}

	const user = await clerkClient.users.getUser(userId);

	return {
		user: JSON.parse(JSON.stringify(user))
	};
};

[!NOTE] If you're planning to add authorization logic within a +layout.server.ts file, I recommend reading this blog post first.

License

MIT