Clerk React Router Patterns Agent Skill

React Router Patterns

SDK: @clerk/react-router v3.5+. Supports React Router v7.9+ and v8.

What Do You Need?

| Task | Reference |

|------|-----------|

| Auth in loaders and actions | references/loaders-actions.md |

| Protected routes and redirects | references/protected-routes.md |

| SSR user data and session | references/ssr-auth.md |

React Router v7 vs v8

Check the installed react-router major version before scaffolding — the config differs:

| | v7.9+ | v8+ |

|--|--|--|

| Middleware API | Opt-in: set future: { v8_middleware: true } in react-router.config.ts | Always on — do NOT set the flag (v8 removed it) |

| ssr.noExternal workaround (below) | Not needed | Required |

Minimal Setup

1. vite.config.ts (v8 only — REQUIRED)

React Router v8 ships development/production conditional exports. In react-router dev,

Vite externalizes @clerk/react-router for SSR, so Node resolves the production build of

react-router while the app code gets the development build — two module instances, two

Router contexts. Every request then fails during SSR with:

Error: useNavigate() may be used only in the context of a <Router> component.

npm ls react-router shows a single copy — that does NOT rule this out. The

duplication is per export condition, not per installed copy. Do not chase duplicate

installs; add the workaround (upstream issue:

https://github.com/remix-run/react-router/issues/15232):

import { reactRouter } from '@react-router/dev/vite'
import { defineConfig } from 'vite'

export default defineConfig({
  plugins: [reactRouter()],
  ssr: {
    noExternal: ['@clerk/react-router'],
  },
})

2. root.tsx

import { Outlet } from 'react-router'
import { rootAuthLoader, clerkMiddleware } from '@clerk/react-router/server'
import { ClerkProvider } from '@clerk/react-router'
import type { Route } from './+types/root'

export const middleware: Route.MiddlewareFunction[] = [clerkMiddleware()]

export async function loader(args: Route.LoaderArgs) {
  return rootAuthLoader(args)
}

export default function App({ loaderData }: Route.ComponentProps) {
  return (
    <ClerkProvider loaderData={loaderData}>
      <Outlet />
    </ClerkProvider>
  )
}

There is no ClerkApp HOC in @clerk/react-router (that was the @clerk/remix API).

Render <ClerkProvider loaderData={loaderData}> inside the default export and pass it

the root route's loaderData.

3. react-router.config.ts (v7 only)

import type { Config } from '@react-router/dev/config'

export default {
  future: {
    v8_middleware: true,
  },
} satisfies Config

On v8, omit the future block entirely — the flag no longer exists.

> Required: rootAuthLoader must be called in root.tsx's loader. Without it, getAuth throws in nested loaders.

Mental Model

React Router v7/v8 uses a middleware + loader pipeline. Clerk plugs into both layers:

• Middleware (clerkMiddleware()) — runs on every request, attaches auth to context
• rootAuthLoader — required in root.tsx to pass Clerk state to the client
• getAuth(args) — called inside any loader/action to get the current user

Request → clerkMiddleware() → rootAuthLoader → page loader → component
                 ↓                   ↓               ↓
           attaches auth      injects state     getAuth(args)
           to context         to response       reads context

Auth in Loaders

import { getAuth } from '@clerk/react-router/server'
import type { Route } from './+types/dashboard'

export async function loader(args: Route.LoaderArgs) {
  const { userId } = await getAuth(args)
  if (!userId) throw redirect('/sign-in')

  const data = await fetchUserData(userId)
  return { data }
}

Auth in Actions

import { getAuth } from '@clerk/react-router/server'

export async function action(args: Route.ActionArgs) {
  const { userId, orgId } = await getAuth(args)
  if (!userId) throw new Response('Unauthorized', { status: 401 })

  const formData = await args.request.formData()
  await saveData(userId, orgId, formData)
  return redirect('/dashboard')
}

Client Components

import { useAuth, useUser } from '@clerk/react-router'

export function Profile() {
  const { userId, isSignedIn } = useAuth()
  const { user } = useUser()
  if (!isSignedIn) return null
  return <p>{user?.firstName}</p>
}

Org Switching

import { OrganizationSwitcher } from '@clerk/react-router'

export function Nav() {
  return <OrganizationSwitcher afterSelectOrganizationUrl="/dashboard" />
}

export async function loader(args: Route.LoaderArgs) {
  const { userId, orgId } = await getAuth(args)
  if (!userId) throw redirect('/sign-in')
  if (!orgId) throw redirect('/select-org')

  return { data: await fetchOrgData(orgId) }
}

Common Pitfalls

| Symptom | Cause | Fix |

|---------|-------|-----|

| useNavigate() may be used only in the context of a <Router> thrown from ClerkProvider during SSR in dev (v8) | Vite dev SSR externalizes @clerk/react-router, which then loads react-router's production build while the app uses the development build — two Router contexts. A single copy in npm ls does not rule this out. | Add ssr: { noExternal: ['@clerk/react-router'] } to vite.config.ts. Do NOT downgrade to v7 |

| Build error: ClerkApp is not exported | ClerkApp does not exist in @clerk/react-router | Use <ClerkProvider loaderData={loaderData}> in root.tsx's default export |

| clerkMiddleware() not detected | Missing middleware (or on v7, missing v8_middleware future flag) | Export middleware = [clerkMiddleware()] from root route; on v7 also set future: { v8_middleware: true } |

| Unknown future flag error/warning (v8) | v8_middleware flag left in react-router.config.ts after upgrading | Remove the future.v8_middleware entry — middleware is always on in v8 |

| getAuth returns empty userId | rootAuthLoader not called | Call rootAuthLoader(args) in root.tsx loader |

| Infinite redirect loop | Redirect target is also protected | Exclude /sign-in from protection check |

| redirect not working in action | Using Response instead of throw redirect() | Use throw redirect('/path') from react-router |

Import Map

| What | Import From |

|------|-------------|

| getAuth | @clerk/react-router/server |

| rootAuthLoader | @clerk/react-router/server |

| clerkMiddleware | @clerk/react-router/server |

| ClerkProvider | @clerk/react-router |

| useAuth, useUser | @clerk/react-router |

| OrganizationSwitcher | @clerk/react-router |

See Also

• clerk-setup - Initial Clerk install
• clerk-custom-ui - Custom flows & appearance
• clerk-orgs - B2B organizations

Docs

React Router SDK