AuthKit TanStack Start

Authentication and session management for TanStack Start applications using WorkOS AuthKit.

> [!NOTE]
> This library is designed for TanStack Start v1.0+. TanStack Start is currently in beta - expect some API changes as the framework evolves.

Installation

``bash
npm install @workos/authkit-tanstack-react-start
`

`bash
pnpm add @workos/authkit-tanstack-react-start
`

Quickstart

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Create a .env file in your project root with the following required variables:

`bash
WORKOS_CLIENT_ID="client_..." # Get from WorkOS dashboard
WORKOS_API_KEY="sk_test_..." # Get from WorkOS dashboard
WORKOS_REDIRECT_URI="http://localhost:3000/api/auth/callback"
WORKOS_COOKIE_PASSWORD="..." # Min 32 characters
`

Generate a secure cookie password (32+ characters):

`bash
openssl rand -base64 24
`

#### Optional Configuration

| Variable | Default | Description |
| ------------------------ | --------------------- | -------------------------------------------- |
| WORKOS_COOKIE_MAX_AGE | 34560000 (400 days) | Cookie lifetime in seconds |
| WORKOS_COOKIE_NAME | wos-session | Session cookie name |
| WORKOS_COOKIE_DOMAIN | None | Cookie domain (for multi-domain sessions) |
| WORKOS_COOKIE_SAMESITE | lax | SameSite attribute (lax, strict, none) |
| WORKOS_API_HOSTNAME | api.workos.com | WorkOS API hostname |

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#### 1. Configure Middleware

Create or update src/start.ts:

`typescript
import { createStart } from '@tanstack/react-start';
import { authkitMiddleware } from '@workos/authkit-tanstack-react-start';

export const startInstance = createStart(() => ({
requestMiddleware: [authkitMiddleware()],
}));
`

#### 2. Create Callback Route

Create src/routes/api/auth/callback.tsx:

`typescript
import { createFileRoute } from '@tanstack/react-router';
import { handleCallbackRoute } from '@workos/authkit-tanstack-react-start';

export const Route = createFileRoute('/api/auth/callback')({
server: {
handlers: {
GET: handleCallbackRoute(),
},
},
});
`

Make sure this matches your WORKOS_REDIRECT_URI environment variable.

#### 3. Add Provider (Optional - only needed for client hooks)

If you want to use useAuth() or other client hooks, wrap your app with AuthKitProvider in src/routes/__root.tsx:

`typescript
import { AuthKitProvider } from '@workos/authkit-tanstack-react-start/client';
import { Outlet, createRootRoute } from '@tanstack/react-router';

export const Route = createRootRoute({
component: RootComponent,
});

function RootComponent() {
return (



);
}
`

If you're only using server-side authentication (getAuth() in loaders), you can skip this step.

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1. Go to WorkOS Dashboard and navigate to the Redirects page.
2. Under Redirect URIs, add your callback URL: http://localhost:3000/api/auth/callback
3. Under Sign-out redirect, set the URL where you want users to be redirected after signing out. If you don't set a sign-out redirect URL, you must set the App homepage URL instead — WorkOS will redirect users there when no sign-out redirect is specified.

Note: If you don't set either the Sign-out redirect or the App homepage URL, WorkOS will redirect users to an error page.

Usage

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Use getAuth() in route loaders or server functions to access the current session:

`typescript
import { createFileRoute, redirect } from '@tanstack/react-router';
import { getAuth, getSignInUrl } from '@workos/authkit-tanstack-react-start';

export const Route = createFileRoute('/dashboard')({
loader: async () => {
const { user } = await getAuth();

if (!user) {
const signInUrl = await getSignInUrl();
throw redirect({ href: signInUrl });
}

return { user };
},
component: DashboardPage,
});

function DashboardPage() {
const { user } = Route.useLoaderData();
return

For client components that need reactive auth state, use the useAuth() hook:

`typescript
'use client'; // Not actually needed in TanStack Start, but shows intent

import { useAuth } from '@workos/authkit-tanstack-react-start/client';

function ProfileButton() {
const { user, loading, signOut } = useAuth();

if (loading) return

`typescript
import { signOut } from '@workos/authkit-tanstack-react-start';

export const Route = createFileRoute('/logout')({
loader: async () => {
await signOut(); // Redirects to WorkOS logout, then back to '/'
},
});
`

Client-side (from useAuth hook):

`typescript
const { signOut } = useAuth();

await signOut({ returnTo: '/goodbye' });
`

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Switch the active organization for multi-org users:

Server-side:

`typescript
import { switchToOrganization } from '@workos/authkit-tanstack-react-start';

// In a server function or loader
const auth = await switchToOrganization({
data: { organizationId: 'org_456' },
});

// Session now has org_456's role, permissions, etc.
`

Client-side:

`typescript
const { switchToOrganization, organizationId } = useAuth();

await switchToOrganization('org_456');
// Auth state updates automatically
`

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Use layout routes to protect multiple pages:

`typescript
// src/routes/_authenticated.tsx
import { createFileRoute, redirect } from '@tanstack/react-router';
import { getAuth, getSignInUrl } from '@workos/authkit-tanstack-react-start';

export const Route = createFileRoute('/_authenticated')({
loader: async ({ location }) => {
const { user } = await getAuth();

if (!user) {
const signInUrl = await getSignInUrl({
data: { returnPathname: location.pathname },
});
throw redirect({ href: signInUrl });
}

return { user };
},
});

// Now all routes under _authenticated require auth:
// - _authenticated/dashboard.tsx
// - _authenticated/profile.tsx
// etc.
`

API Reference

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These functions can be called from route loaders, server functions, or server route handlers.

#### getAuth()

Retrieves the current user session.

`typescript
const { user } = await getAuth();

if (user) {
console.log(user.email);
console.log(user.firstName);
}
`

Returns: UserInfo | NoUserInfo

UserInfo fields:

- user - The authenticated user object
- sessionId - WorkOS session ID
- organizationId - Active organization (if in org context)
- role - User's role in the organization
- roles - Array of role strings
- permissions - Array of permission strings
- entitlements - Array of entitlement strings
- featureFlags - Array of feature flag strings
- impersonator - Impersonator details (if being impersonated)
- accessToken - JWT access token

#### signOut(options?)

Signs out the current user and redirects to WorkOS logout.

`typescript
await signOut();
await signOut({ data: { returnTo: '/goodbye' } });
`

Options:

- returnTo - Path to redirect to after logout (default: /)

#### switchToOrganization(options)

Switches to a different organization and refreshes the session with new claims.

`typescript
const auth = await switchToOrganization({
data: {
organizationId: 'org_123',
returnTo: '/dashboard', // optional
},
});
`

Options:

- organizationId - The organization ID to switch to (required)
- returnTo - Path to redirect to if auth fails

Returns: UserInfo with updated organization claims

#### getSignInUrl(options?)

Generates a sign-in URL for redirecting to AuthKit.

`typescript
// Basic usage
const url = await getSignInUrl();

// With return path
const url = await getSignInUrl({
data: { returnPathname: '/dashboard' },
});
`

Options:

- returnPathname - Path to return to after sign-in

#### getSignUpUrl(options?)

Generates a sign-up URL for redirecting to AuthKit.

`typescript
const url = await getSignUpUrl();
const url = await getSignUpUrl({
data: { returnPathname: '/onboarding' },
});
`

Options:

- returnPathname - Path to return to after sign-up

#### getAuthorizationUrl(options)

Advanced: Generate a custom authorization URL with full control.

`typescript
const url = await getAuthorizationUrl({
data: {
screenHint: 'sign-in',
returnPathname: '/dashboard',
redirectUri: 'https://example.com/callback', // override default
},
});
`

Options:

- screenHint - 'sign-in' or 'sign-up'
- returnPathname - Return path after authentication
- redirectUri - Override the default redirect URI

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#### handleCallbackRoute

Handles the OAuth callback from WorkOS. Use this in your callback route.

Basic usage:

`typescript
import { createFileRoute } from '@tanstack/react-router';
import { handleCallbackRoute } from '@workos/authkit-tanstack-react-start';

export const Route = createFileRoute('/api/auth/callback')({
server: {
handlers: {
GET: handleCallbackRoute(),
},
},
});
`

With hooks for custom logic:

`typescript
export const Route = createFileRoute('/api/auth/callback')({
server: {
handlers: {
GET: handleCallbackRoute({
onSuccess: async ({ user, authenticationMethod }) => {
// Create user record in your database
await db.users.upsert({ id: user.id, email: user.email });
// Track analytics
analytics.track('User Signed In', { method: authenticationMethod });
},
onError: ({ error, request }) => {
// Custom error handling
console.error('Auth failed:', error);
return new Response(JSON.stringify({ error: 'Authentication failed' }), {
status: 500,
headers: { 'Content-Type': 'application/json' },
});
},
}),
},
},
});
`

Options:

- onSuccess?: (data) => Promise - Called after successful authentication with user data, tokens, and authentication method
- onError?: ({ error, request }) => Response - Custom error handler that returns a Response
- returnPathname?: string - Override the redirect path after authentication (defaults to state or /)

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Available from @workos/authkit-tanstack-react-start/client. Requires wrapper.

#### useAuth(options?)

Access authentication state and methods in client components.

`typescript
import { useAuth } from '@workos/authkit-tanstack-react-start/client';

function MyComponent() {
const { user, loading, signOut } = useAuth();

if (loading) return

- ensureSignedIn?: boolean - If true, automatically triggers sign-in flow for unauthenticated users

Returns: AuthContextType with:

- user - Current user or null
- loading - Loading state
- sessionId, organizationId, role, roles, permissions, entitlements, featureFlags, impersonator
- getAuth() - Refresh auth state
- refreshAuth(options) - Refresh session with optional org switch
- signOut(options) - Sign out
- switchToOrganization(orgId) - Switch organizations

#### useAccessToken()

Manage access tokens with automatic refresh.

`typescript
import { useAccessToken } from '@workos/authkit-tanstack-react-start/client';

function ApiCaller() {
const { accessToken, loading, getAccessToken } = useAccessToken();

const callApi = async () => {
const token = await getAccessToken(); // Always fresh

const response = await fetch('/api/data', {
headers: { Authorization: Bearer ${token} },
});
};

return Fetch Data;
}
`

Returns:

- accessToken - Current token (may be stale)
- loading - Loading state
- error - Last error or null
- refresh() - Manually refresh token
- getAccessToken() - Get guaranteed fresh token

#### useTokenClaims()

Parse and decode JWT claims from the access token.

`typescript
import { useTokenClaims } from '@workos/authkit-tanstack-react-start/client';

function ClaimsDisplay() {
const claims = useTokenClaims();

if (!claims) return null;

return (


#### authkitMiddleware(options?)

Processes authentication on every request. Validates tokens, refreshes sessions, and provides auth context to server functions.

`typescript
import { authkitMiddleware } from '@workos/authkit-tanstack-react-start';

// Basic usage
authkitMiddleware();

// With custom redirect URI (e.g., for Vercel preview deployments)
authkitMiddleware({
redirectUri: 'https://preview-123.example.com/api/auth/callback',
});
`

Options:

- redirectUri - Override the default redirect URI from WORKOS_REDIRECT_URI. Useful for dynamic environments like preview deployments.

TypeScript

This library is fully typed. Common types:

`typescript
import type {
User,
Session,
UserInfo,
NoUserInfo,
Impersonator
} from '@workos/authkit-tanstack-react-start';

// User object from WorkOS
const user: User = {
id: string;
email: string;
firstName: string | null;
lastName: string | null;
emailVerified: boolean;
profilePictureUrl: string | null;
// ... more fields
};

// Auth result from getAuth()
const auth: UserInfo | NoUserInfo = await getAuth();
`

Route loaders get full type inference:

`typescript
export const Route = createFileRoute('/profile')({
loader: async () => {
const { user } = await getAuth();
return { user }; // Fully typed
},
component: ProfilePage,
});

function ProfilePage() {
const { user } = Route.useLoaderData(); // user is typed!
}
`

How It Works

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1. Middleware runs on every request - validates/refreshes session, stores auth in context
2. Route loaders call getAuth() - retrieves auth from middleware context
3. No client bundle bloat - server functions create RPC boundaries automatically

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1. Provider wraps app - provides auth context to hooks
2. Hooks call server actions - fetch auth state via RPC
3. State updates automatically - on tab focus, refresh, org switch

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- Server-only apps: Just use getAuth() in loaders - no provider needed
- Client hooks needed: Add provider to use useAuth(), useAccessToken(), etc.
- Flexibility: Start server-only, add client hooks later

Common Patterns

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`typescript
// Get sign-in URL in loader
export const Route = createFileRoute('/')({
loader: async () => {
const { user } = await getAuth();
const signInUrl = await getSignInUrl();
return { user, signInUrl };
},
component: HomePage,
});

function HomePage() {
const { user, signInUrl } = Route.useLoaderData();

if (!user) {
return Sign In with AuthKit;
}

return

`typescript
// src/routes/_authenticated.tsx
import { createFileRoute, redirect } from '@tanstack/react-router';
import { getAuth, getSignInUrl } from '@workos/authkit-tanstack-react-start';

export const Route = createFileRoute('/_authenticated')({
loader: async ({ location }) => {
const { user } = await getAuth();

if (!user) {
const signInUrl = await getSignInUrl({
data: { returnPathname: location.pathname },
});
throw redirect({ href: signInUrl });
}

return { user };
},
});

// All child routes require authentication:
// - _authenticated/dashboard.tsx
// - _authenticated/settings.tsx
`

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`typescript
import { useAuth } from '@workos/authkit-tanstack-react-start/client';

function OrgSwitcher() {
const { organizationId, switchToOrganization } = useAuth();

return (
value={organizationId || ''}
onChange={(e) => switchToOrganization(e.target.value)}
>
Acme Corp
Other Company

);
}
`

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Loader (server-side):

`typescript
loader: async () => {
const { user, organizationId, role } = await getAuth();
return { user, organizationId, role };
};
`

Component (from loader data):

`typescript
function MyPage() {
const { user } = Route.useLoaderData();
// ...
}
`

Client hook (reactive):

`typescript
function MyClientComponent() {
const { user, loading } = useAuth();
// Updates on session changes
}
`

Troubleshooting

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You forgot to add authkitMiddleware() to src/start.ts. See step 1 in setup.

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You're calling useAuth() but haven't wrapped your app with . See step 3 in setup.

If you don't need client hooks, use getAuth() in loaders instead.

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The middleware validates configuration on first request. If you see errors about missing variables:

1. Check your .env file exists
2. Verify all required variables are set
3. Ensure WORKOS_COOKIE_PASSWORD is 32+ characters
4. Restart your dev server after changing env vars

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Make sure you're importing from the right path:

`typescript
// Server functions
import { getAuth, signOut } from '@workos/authkit-tanstack-react-start';

// Client hooks
import { useAuth } from '@workos/authkit-tanstack-react-start/client';
`

Don't import client hooks in server code or vice versa.

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You're trying to call a server function from a beforeLoad hook or client component.

Wrong:

`typescript
beforeLoad: async () => {
const { user } = await getAuth(); // ❌ Runs on client during hydration
};
`

Right:

`typescript
loader: async () => {
const { user } = await getAuth(); // ✅ Server-only during SSR
};
`

Use useAuth() client hook for client components, or move logic to a loader.

Example Application

Check the /example directory for a complete working application demonstrating:

- Server-side authentication in loaders
- Client-side hooks with provider
- Protected routes
- Organization switching
- Sign in/out flows
- Access token management

Run it locally:

`bash
cd example
pnpm install
pnpm dev
``

Framework Compatibility

- TanStack Start: v1.132.0+
- TanStack Router: v1.132.0+
- React: 18.0+
- Node.js: 18+

Related

- WorkOS AuthKit Documentation
- TanStack Start Documentation
- WorkOS Node SDK

License

MIT