Clerk Knowledge Patch

Clerk Knowledge Patch

Use this guide when implementing, upgrading, or debugging Clerk authentication, authorization, Organizations, Billing, SDKs, components, or deployment architecture. Start with the migration notes, then open the matching reference.

Reference index

Breaking migrations and changed defaults

Migrate custom flows to Core 3

Core 3 uses named factor methods and explicit finalization. Do not port old attemptFirstFactor() or createdSessionId activation literally.

const { signIn } = useSignIn()
await signIn.create({ identifier: email })
await signIn.password({ password })

if (signIn.status === 'complete') {
  await signIn.finalize({ navigate: () => router.push('/') })
}

• Email-code sign-in uses signIn.emailCode.sendCode() and verifyCode().
• Sign-up verification lives under signUp.verifications.
• MFA uses the signIn.mfa namespace.
• Read field failures from errors.fields, other handled failures from errors.global, and unparsed failures from errors.raw.
• Attempt objects change identity as a flow advances; include the attempt object in React dependency arrays.
• Use clerk.setActive() for an existingSession; use an attempt's finalize() for a newly completed attempt.

Treat pending sessions as unauthenticated by default

Organization selection, forced-password reset, or required-MFA setup can leave a session pending. IDs are normally null and protected routes reject it. After finalization, inspect session.currentTask and route to the task UI. Use treatPendingAsSignedOut: false only where pending identity is intentional.

Update request-authentication checks

JavaScript authenticateRequest() reports isAuthenticated; isSignedIn is deprecated. The result distinguishes signed-in, signed-out, and handshake, exposes tokenType, and converts through toAuth().

const state = await client.authenticateRequest(request, {
  authorizedParties: ['https://app.example.com'],
})
if (!state.isAuthenticated) return new Response('Unauthorized', { status: 401 })

Next.js auth() accepts session tokens by default. Explicitly set acceptsToken for API keys, OAuth tokens, or mixed machine routes, then branch on tokenType and scopes.

Account for SDK and prop migrations

• Python 5.x generated schemas can change incompatibly even in patch or minor releases. Pin exact versions and inspect request/response changes; 6.0.0 changes users.update() and organizations.update() inputs.
• Go v2 requires Go 1.24+ and imports from github.com/clerk/clerk-sdk-go/v2.
• <SignOutButton> takes redirectUrl and sessionId directly; signOutOptions is deprecated.
• Move <UserButton> sign-out destinations to <ClerkProvider>; only afterSwitchSessionUrl stays local.
• satelliteAutoSync defaults to false; explicitly enable automatic synchronization.
• Use CLERK_JS_URL, not CLERK_JS; replace old after-sign-in/up variables with fallback or force redirect settings.
• Replace sessions.verifySession() with full-request authentication or direct JWT validation.
• Import extension background clients from @clerk/chrome-extension/client with background: true.
• Move enterprise administration from /saml_connections to /v1/enterprise_connections.

Rename appearance variables

Prepare for removal of these deprecated names:

Authentication quick reference

Enumeration-safe combined sign-in and sign-up

Use signIn.create({ identifier, signUpIfMissing: true }). Verification returns sign_up_if_missing_transfer for a new account, after which signUp.create({ transfer: true }) preserves the verified identifier. This excludes password, username, restricted, and waitlist flows. The embedded combined flow can also perform this verification-first behavior under strict enumeration protection when the instance is open-access and starts without a password.

Reverification

Server code checks auth.has({ reverification: preset }) and returns reverificationError(preset); client code wraps the operation with useReverification(). If the user lacks a second factor, a requested second- or multi-factor level downgrades to first-factor verification. Native Expo must provide onNeedsReverification; the prebuilt modal is web-only.

Session-token claims

Current session tokens include v, pla, fea, sts, and an o object only when an Organization is active. Keep custom claims below 1.2 KB so the complete cookie stays below browser limits. Use CLERK_JWT_KEY or a supplied jwtKey for networkless verification.

OAuth and machine tokens

• Clerk exposes OAuth/OIDC discovery, token, user-info, and token-info endpoints.
• Dynamic client registration is public and forces the consent screen on.
• API routes must opt into oauth_token; API-key routes must opt into api_key.
• M2M creation supports locally verifiable JWTs or immediately revocable opaque tokens.
• A custom JWT template is independent of a session and cannot include session-bound sid, v, pla, or fea.

Framework and deployment quick reference

Next.js

Calling server-side auth() makes the route dynamic. Client useAuth() stays static by default; scope <ClerkProvider dynamic> narrowly, optionally under <Suspense>. Built-in FAPI proxying is available through clerkMiddleware() or App Router proxy handlers.

Astro

Endpoints use synchronous locals.auth(), await locals.currentUser(), and clerkClient(context). Never serialize the complete Backend User because it contains privateMetadata. Match isStatic on Clerk controls to whether the page is prerendered.

Production sessions

The long-lived __client JWT on the FAPI domain is distinct from the one-minute __session JWT on the exact application domain. Cross-subdomain APIs should receive the session token in Authorization. An expired server-rendered token can trigger a 307 FAPI handshake; preserve Clerk's context headers through adapters and proxies.

Environment topology

Development instances have a 100-user cap and cannot transfer users to production. Staging normally needs a separate application and domain. A preview sharing production identity must use production keys on a subdomain of the same root domain; provider-owned preview domains use development keys.

Organizations and authorization quick reference

• Store the Organization ID on tenant-owned records and verify it on every query.
• Active Organization is tab-local, but the shared cookie can reflect another active tab. Fetch a token in the current tab and send it as a bearer token for tenant-scoped background work.
• An unknown or unauthorized slug leaves the prior Organization active. Compare route slug with authenticated orgSlug before reading tenant data.
• System Permissions are not session claims. Use equivalent Custom Permissions for server-side has() checks.
• A Custom Permission succeeds only while the active Organization Plan includes its corresponding Feature.
• Role Set changes propagate to assigned Organizations; switching or deleting sets requires explicit Role remapping.
• Organization collection hooks fetch nothing unless each collection is requested.

Billing quick reference

Clerk Billing objects are separate from Stripe Billing objects. The service is USD-only and has no native refunds, tax/VAT calculation, 3D Secure confirmation, or merchant-of-record service. Authorize entitlements with has() or <Show>, not display hooks.

For custom checkout, call start(), confirm(), then finalize() to synchronize identity state. New cards require <PaymentElementProvider> and <PaymentElement />; existing cards pass paymentMethodId. Billing buttons must be inside <Show when="signed-in">, and Organization checkout also requires an Active Organization.

UI and customization quick reference

• <Show> accepts roles, permissions, features, plans, or a callback, but only hides client content; repeat sensitive checks on the server.
• <GoogleOneTap> needs custom Google credentials and does not return provider access tokens.
• Embedded <Waitlist /> needs Waitlist mode plus waitlistUrl.
• Global appearance supports theme, options, variables, elements, captcha, and cssLayerName; direct component appearance wins for one instance.
• For Tailwind v4, place Clerk in an earlier cascade layer than utilities.
• Stable DOM hooks are the human-readable cl-* classes before the lock marker; remove cl- when using an appearance.elements key.
• Hosted Account Portal pages allow Dashboard customization only; prebuilt components allow CSS changes; Elements allows custom HTML/CSS but still owns flow order; only API-built flows control authentication logic.

Native Expo quick reference

@clerk/expo 3.1 requires Expo SDK 53+. Its config plugin installs native iOS and Android dependencies. AuthView, UserButton, and UserProfileView come from @clerk/expo/native; native Google sign-in uses platform-native APIs. Set the plugin's appleSignIn option to false when the entitlement is not needed.

Use useUserProfileModal(), useNativeSession(), and useNativeAuthEvents() for native state. Trusted-device APIs can enroll a device for later biometric sign-in. Cloudflare bot protection is unsupported in Expo and must be disabled there.

Before shipping

1. Confirm accepted token types and authorized parties for every backend route.
2. Enforce tenant and entitlement checks on the server, even when UI controls hide content.
3. Handle handshake, pending-session, and reverification states explicitly.
4. Check redirect URLs, Account Portal return targets, proxy headers, and satellite origins.
5. Capture API-key secrets and OAuth client secrets at creation; they are not generally retrievable later.
6. Recheck SDK-specific deprecations and schema changes in the relevant reference.