From a9a2589cec22fc912c1e3738d8d510a433068252 Mon Sep 17 00:00:00 2001
From: Keiran Flanigan <keiran@aeliox.com>
Date: Mon, 29 Sep 2025 10:16:18 -0700
Subject: [PATCH 1/4] pass locale to stripe elements

---
 packages/clerk-js/sandbox/app.ts              |  23 +-
 packages/clerk-js/src/core/clerk.ts           |   8 +-
 .../src/react/__tests__/commerce.test.tsx     | 321 ++++++++++++++++++
 packages/shared/src/react/commerce.tsx        |  17 +
 4 files changed, 357 insertions(+), 12 deletions(-)
 create mode 100644 packages/shared/src/react/__tests__/commerce.test.tsx

diff --git a/packages/clerk-js/sandbox/app.ts b/packages/clerk-js/sandbox/app.ts
index 15d45afc722..f9793b0918a 100644
--- a/packages/clerk-js/sandbox/app.ts
+++ b/packages/clerk-js/sandbox/app.ts
@@ -237,19 +237,20 @@ function otherOptions() {
   });
 
   const updateOtherOptions = () => {
-    void Clerk.__unstable__updateProps({
-      options: Object.fromEntries(
-        Object.entries(otherOptionsInputs).map(([key, input]) => {
-          sessionStorage.setItem(key, input.value);
+    const options = Object.fromEntries(
+      Object.entries(otherOptionsInputs).map(([key, input]) => {
+        sessionStorage.setItem(key, input.value);
 
-          if (key === 'localization') {
-            return [key, l[input.value as keyof typeof l]];
-          }
+        if (key === 'localization') {
+          const localizationObj = l[input.value as keyof typeof l];
+          return [key, localizationObj];
+        }
 
-          return [key, input.value];
-        }),
-      ),
-    });
+        return [key, input.value];
+      }),
+    );
+
+    void Clerk.__unstable__updateProps({ options });
   };
 
   Object.values(otherOptionsInputs).forEach(input => {
diff --git a/packages/clerk-js/src/core/clerk.ts b/packages/clerk-js/src/core/clerk.ts
index 6e676e2d371..f9971e10926 100644
--- a/packages/clerk-js/src/core/clerk.ts
+++ b/packages/clerk-js/src/core/clerk.ts
@@ -2375,10 +2375,16 @@ export class Clerk implements ClerkInterface {
     // 2. clerk-js initializes propA with a default value
     // 3. The customer update propB independently of propA and window.Clerk.updateProps is called
     // 4. If we don't merge the new props with the current options, propA will be reset to undefined
+    const mergedOptions = { ...this.#options, ..._props.options };
+
+    // Update the Clerk instance's internal options
+    this.#options = mergedOptions;
+
     const props = {
       ..._props,
-      options: this.#initOptions({ ...this.#options, ..._props.options }),
+      options: this.#initOptions(mergedOptions),
     };
+
     return this.#componentControls?.ensureMounted().then(controls => controls.updateProps(props));
   };
 
diff --git a/packages/shared/src/react/__tests__/commerce.test.tsx b/packages/shared/src/react/__tests__/commerce.test.tsx
new file mode 100644
index 00000000000..bd18ae14850
--- /dev/null
+++ b/packages/shared/src/react/__tests__/commerce.test.tsx
@@ -0,0 +1,321 @@
+import { render, screen } from '@testing-library/react';
+import '@testing-library/jest-dom';
+import React from 'react';
+
+import { OptionsContext } from '../contexts';
+import { __experimental_PaymentElementProvider, __experimental_PaymentElement } from '../commerce';
+
+// Mock the Stripe components
+jest.mock('../stripe-react', () => ({
+  Elements: ({ children, options }: { children: React.ReactNode; options: any }) => (
+    <div
+      data-testid='stripe-elements'
+      data-locale={options.locale}
+    >
+      {children}
+    </div>
+  ),
+  PaymentElement: ({ fallback }: { fallback?: React.ReactNode }) => (
+    <div data-testid='stripe-payment-element'>{fallback}</div>
+  ),
+  useElements: () => null,
+  useStripe: () => null,
+}));
+
+// Mock the hooks
+const mockGetOption = jest.fn();
+jest.mock('../hooks/useClerk', () => ({
+  useClerk: () => ({
+    __internal_loadStripeJs: jest.fn().mockResolvedValue(() => Promise.resolve({})),
+    __internal_getOption: mockGetOption,
+    __unstable__environment: {
+      commerceSettings: {
+        billing: {
+          stripePublishableKey: 'pk_test_123',
+        },
+      },
+      displayConfig: {
+        userProfileUrl: 'https://example.com/profile',
+        organizationProfileUrl: 'https://example.com/org-profile',
+      },
+    },
+  }),
+}));
+
+jest.mock('../hooks/useUser', () => ({
+  useUser: () => ({
+    user: {
+      id: 'user_123',
+      initializePaymentSource: jest.fn().mockResolvedValue({
+        externalGatewayId: 'acct_123',
+        externalClientSecret: 'seti_123',
+        paymentMethodOrder: ['card'],
+      }),
+    },
+  }),
+}));
+
+jest.mock('../hooks/useOrganization', () => ({
+  useOrganization: () => ({
+    organization: null,
+  }),
+}));
+
+jest.mock('swr', () => ({
+  __esModule: true,
+  default: () => ({ data: { loadStripe: jest.fn().mockResolvedValue({}) } }),
+}));
+
+jest.mock('swr/mutation', () => ({
+  __esModule: true,
+  default: () => ({
+    data: {
+      externalGatewayId: 'acct_123',
+      externalClientSecret: 'seti_123',
+      paymentMethodOrder: ['card'],
+    },
+    trigger: jest.fn().mockResolvedValue({
+      externalGatewayId: 'acct_123',
+      externalClientSecret: 'seti_123',
+      paymentMethodOrder: ['card'],
+    }),
+  }),
+}));
+
+describe('PaymentElement Localization', () => {
+  const mockCheckout = {
+    id: 'checkout_123',
+    plan: {
+      id: 'plan_123',
+      name: 'Test Plan',
+      description: 'Test plan description',
+      fee: { amount: 1000, amountFormatted: '$10.00', currency: 'usd', currencySymbol: '$' },
+      annualFee: { amount: 10000, amountFormatted: '$100.00', currency: 'usd', currencySymbol: '$' },
+      annualMonthlyFee: { amount: 833, amountFormatted: '$8.33', currency: 'usd', currencySymbol: '$' },
+      currency: 'usd',
+      interval: 'month' as const,
+      intervalCount: 1,
+      maxAllowedInstances: 1,
+      trialDays: 0,
+      isAddon: false,
+      isPopular: false,
+      isPerSeat: false,
+      isUsageBased: false,
+      isFree: false,
+      isLegacy: false,
+      isDefault: false,
+      isRecurring: true,
+      hasBaseFee: true,
+      forPayerType: 'user' as const,
+      publiclyVisible: true,
+      slug: 'test-plan',
+      avatarUrl: '',
+      freeTrialDays: 0,
+      freeTrialEnabled: false,
+      pathRoot: '/',
+      reload: jest.fn(),
+      features: [],
+      limits: {},
+      metadata: {},
+    },
+    totals: {
+      subtotal: { amount: 1000, amountFormatted: '$10.00', currency: 'usd', currencySymbol: '$' },
+      grandTotal: { amount: 1000, amountFormatted: '$10.00', currency: 'usd', currencySymbol: '$' },
+      taxTotal: { amount: 0, amountFormatted: '$0.00', currency: 'usd', currencySymbol: '$' },
+      totalDueNow: { amount: 1000, amountFormatted: '$10.00', currency: 'usd', currencySymbol: '$' },
+      credit: { amount: 0, amountFormatted: '$0.00', currency: 'usd', currencySymbol: '$' },
+      pastDue: { amount: 0, amountFormatted: '$0.00', currency: 'usd', currencySymbol: '$' },
+    },
+    status: 'needs_confirmation' as const,
+    error: null,
+    fetchStatus: 'idle' as const,
+    confirm: jest.fn(),
+    start: jest.fn(),
+    clear: jest.fn(),
+    finalize: jest.fn(),
+    getState: jest.fn(),
+    isConfirming: false,
+    isStarting: false,
+    planPeriod: 'month' as const,
+    externalClientSecret: 'seti_123',
+    externalGatewayId: 'acct_123',
+    isImmediatePlanChange: false,
+    paymentMethodOrder: ['card'],
+    freeTrialEndsAt: null,
+    payer: {
+      id: 'payer_123',
+      createdAt: new Date('2023-01-01'),
+      updatedAt: new Date('2023-01-01'),
+      imageUrl: null,
+      userId: 'user_123',
+      email: 'test@example.com',
+      firstName: 'Test',
+      lastName: 'User',
+      organizationId: undefined,
+      organizationName: undefined,
+      pathRoot: '/',
+      reload: jest.fn(),
+    },
+  };
+
+  const renderWithLocale = (locale: string) => {
+    // Mock the __internal_getOption to return the expected localization
+    mockGetOption.mockImplementation(key => {
+      if (key === 'localization') {
+        return { locale };
+      }
+      return undefined;
+    });
+
+    const options = {
+      localization: { locale },
+    };
+
+    return render(
+      <OptionsContext.Provider value={options}>
+        <__experimental_PaymentElementProvider checkout={mockCheckout}>
+          <__experimental_PaymentElement fallback={<div>Loading...</div>} />
+        </__experimental_PaymentElementProvider>
+      </OptionsContext.Provider>,
+    );
+  };
+
+  it('should pass the correct locale to Stripe Elements', () => {
+    renderWithLocale('es');
+
+    const elements = screen.getByTestId('stripe-elements');
+    expect(elements).toHaveAttribute('data-locale', 'es');
+  });
+
+  it('should default to "en" when no locale is provided', () => {
+    // Mock the __internal_getOption to return undefined for localization
+    mockGetOption.mockImplementation(key => {
+      if (key === 'localization') {
+        return undefined;
+      }
+      return undefined;
+    });
+
+    const options = {};
+
+    render(
+      <OptionsContext.Provider value={options}>
+        <__experimental_PaymentElementProvider checkout={mockCheckout}>
+          <__experimental_PaymentElement fallback={<div>Loading...</div>} />
+        </__experimental_PaymentElementProvider>
+      </OptionsContext.Provider>,
+    );
+
+    const elements = screen.getByTestId('stripe-elements');
+    expect(elements).toHaveAttribute('data-locale', 'en');
+  });
+
+  it('should handle different locale values', () => {
+    const locales = ['en', 'es', 'fr', 'de', 'it'];
+
+    locales.forEach(locale => {
+      const { unmount } = renderWithLocale(locale);
+
+      const elements = screen.getByTestId('stripe-elements');
+      expect(elements).toHaveAttribute('data-locale', locale);
+
+      unmount();
+    });
+  });
+
+  it('should handle undefined localization object', () => {
+    // Mock the __internal_getOption to return undefined for localization
+    mockGetOption.mockImplementation(key => {
+      if (key === 'localization') {
+        return undefined;
+      }
+      return undefined;
+    });
+
+    const options = {
+      localization: undefined,
+    };
+
+    render(
+      <OptionsContext.Provider value={options}>
+        <__experimental_PaymentElementProvider checkout={mockCheckout}>
+          <__experimental_PaymentElement fallback={<div>Loading...</div>} />
+        </__experimental_PaymentElementProvider>
+      </OptionsContext.Provider>,
+    );
+
+    const elements = screen.getByTestId('stripe-elements');
+    expect(elements).toHaveAttribute('data-locale', 'en');
+  });
+
+  it('should work with full LocalizationResource structure like ClerkProvider', () => {
+    // Mock the __internal_getOption to return the expected localization
+    mockGetOption.mockImplementation(key => {
+      if (key === 'localization') {
+        return { locale: 'fr-FR' };
+      }
+      return undefined;
+    });
+
+    // This test simulates the actual ClerkProvider usage pattern:
+    // import { frFR } from '@clerk/localizations';
+    // <ClerkProvider localization={frFR}>
+    const options = {
+      localization: {
+        locale: 'fr-FR',
+        // This would normally contain all the translation strings from frFR
+        // but we only need the locale property for our implementation
+      },
+    };
+
+    render(
+      <OptionsContext.Provider value={options}>
+        <__experimental_PaymentElementProvider checkout={mockCheckout}>
+          <__experimental_PaymentElement fallback={<div>Loading...</div>} />
+        </__experimental_PaymentElementProvider>
+      </OptionsContext.Provider>,
+    );
+
+    const elements = screen.getByTestId('stripe-elements');
+    // Should normalize 'fr-FR' to 'fr' for Stripe compatibility
+    expect(elements).toHaveAttribute('data-locale', 'fr');
+  });
+
+  it('should normalize full locale strings to 2-letter codes for Stripe', () => {
+    const testCases = [
+      { input: 'en-US', expected: 'en' },
+      { input: 'fr-FR', expected: 'fr' },
+      { input: 'es-ES', expected: 'es' },
+      { input: 'de-DE', expected: 'de' },
+      { input: 'it-IT', expected: 'it' },
+      { input: 'pt-BR', expected: 'pt' },
+    ];
+
+    testCases.forEach(({ input, expected }) => {
+      // Mock the __internal_getOption to return the expected localization
+      mockGetOption.mockImplementation(key => {
+        if (key === 'localization') {
+          return { locale: input };
+        }
+        return undefined;
+      });
+
+      const options = {
+        localization: { locale: input },
+      };
+
+      const { unmount } = render(
+        <OptionsContext.Provider value={options}>
+          <__experimental_PaymentElementProvider checkout={mockCheckout}>
+            <__experimental_PaymentElement fallback={<div>Loading...</div>} />
+          </__experimental_PaymentElementProvider>
+        </OptionsContext.Provider>,
+      );
+
+      const elements = screen.getByTestId('stripe-elements');
+      expect(elements).toHaveAttribute('data-locale', expected);
+
+      unmount();
+    });
+  });
+});
diff --git a/packages/shared/src/react/commerce.tsx b/packages/shared/src/react/commerce.tsx
index 72fd978f4b1..0e7251cd2ba 100644
--- a/packages/shared/src/react/commerce.tsx
+++ b/packages/shared/src/react/commerce.tsx
@@ -62,6 +62,21 @@ const useInternalEnvironment = () => {
   return clerk.__unstable__environment as unknown as EnvironmentResource | null | undefined;
 };
 
+const useLocalization = () => {
+  const clerk = useClerk();
+
+  let locale = 'en';
+  try {
+    const localization = clerk.__internal_getOption('localization');
+    locale = localization?.locale || 'en';
+  } catch (_) {}
+
+  // Normalize locale to 2-letter language code for Stripe compatibility
+  const normalizedLocale = locale.split('-')[0];
+
+  return normalizedLocale;
+};
+
 const usePaymentSourceUtils = (forResource: ForPayerType = 'user') => {
   const { organization } = useOrganization();
   const { user } = useUser();
@@ -206,6 +221,7 @@ const PaymentElementProvider = ({ children, ...props }: PropsWithChildren<Paymen
 
 const PaymentElementInternalRoot = (props: PropsWithChildren) => {
   const { stripe, externalClientSecret, stripeAppearance } = usePaymentElementContext();
+  const locale = useLocalization();
 
   if (stripe && externalClientSecret) {
     return (
@@ -219,6 +235,7 @@ const PaymentElementInternalRoot = (props: PropsWithChildren) => {
           appearance: {
             variables: stripeAppearance,
           },
+          locale: locale as any,
         }}
       >
         <ValidateStripeUtils>{props.children}</ValidateStripeUtils>

From cca53a0bba848557094d82d2e277bfc275835a5b Mon Sep 17 00:00:00 2001
From: Keiran Flanigan <keiran@aeliox.com>
Date: Mon, 29 Sep 2025 10:42:02 -0700
Subject: [PATCH 2/4] changeset

---
 .changeset/cold-bottles-watch.md | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 .changeset/cold-bottles-watch.md

diff --git a/.changeset/cold-bottles-watch.md b/.changeset/cold-bottles-watch.md
new file mode 100644
index 00000000000..e57ff6acfba
--- /dev/null
+++ b/.changeset/cold-bottles-watch.md
@@ -0,0 +1,6 @@
+---
+'@clerk/clerk-js': patch
+'@clerk/shared': patch
+---
+
+Pass current localization value to Stripe Elements

From 9f503546790e0de9de7c329af06f29a7d0b1f0ca Mon Sep 17 00:00:00 2001
From: Keiran Flanigan <keiran@aeliox.com>
Date: Mon, 29 Sep 2025 10:53:09 -0700
Subject: [PATCH 3/4] feedback

---
 packages/clerk-js/src/core/clerk.ts    | 9 ++++++---
 packages/shared/src/react/commerce.tsx | 4 +++-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/packages/clerk-js/src/core/clerk.ts b/packages/clerk-js/src/core/clerk.ts
index f9971e10926..c014cdb39b0 100644
--- a/packages/clerk-js/src/core/clerk.ts
+++ b/packages/clerk-js/src/core/clerk.ts
@@ -2377,12 +2377,15 @@ export class Clerk implements ClerkInterface {
     // 4. If we don't merge the new props with the current options, propA will be reset to undefined
     const mergedOptions = { ...this.#options, ..._props.options };
 
-    // Update the Clerk instance's internal options
-    this.#options = mergedOptions;
+    // Process the merged options to ensure consistency between internal state and emitted props
+    const processedOptions = this.#initOptions(mergedOptions);
+
+    // Update the Clerk instance's internal options with processed data
+    this.#options = processedOptions;
 
     const props = {
       ..._props,
-      options: this.#initOptions(mergedOptions),
+      options: processedOptions,
     };
 
     return this.#componentControls?.ensureMounted().then(controls => controls.updateProps(props));
diff --git a/packages/shared/src/react/commerce.tsx b/packages/shared/src/react/commerce.tsx
index 0e7251cd2ba..ca143a6aa74 100644
--- a/packages/shared/src/react/commerce.tsx
+++ b/packages/shared/src/react/commerce.tsx
@@ -69,7 +69,9 @@ const useLocalization = () => {
   try {
     const localization = clerk.__internal_getOption('localization');
     locale = localization?.locale || 'en';
-  } catch (_) {}
+  } catch {
+    // ignore errors
+  }
 
   // Normalize locale to 2-letter language code for Stripe compatibility
   const normalizedLocale = locale.split('-')[0];

From a7f50d0c9d5f423b526a9eb105d4dd6d6ac207a8 Mon Sep 17 00:00:00 2001
From: Keiran Flanigan <keiran@aeliox.com>
Date: Mon, 29 Sep 2025 11:02:23 -0700
Subject: [PATCH 4/4] linter fix

---
 packages/shared/src/react/__tests__/commerce.test.tsx | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/packages/shared/src/react/__tests__/commerce.test.tsx b/packages/shared/src/react/__tests__/commerce.test.tsx
index bd18ae14850..9d090d8dff3 100644
--- a/packages/shared/src/react/__tests__/commerce.test.tsx
+++ b/packages/shared/src/react/__tests__/commerce.test.tsx
@@ -1,9 +1,10 @@
-import { render, screen } from '@testing-library/react';
 import '@testing-library/jest-dom';
+
+import { render, screen } from '@testing-library/react';
 import React from 'react';
 
+import { __experimental_PaymentElement, __experimental_PaymentElementProvider } from '../commerce';
 import { OptionsContext } from '../contexts';
-import { __experimental_PaymentElementProvider, __experimental_PaymentElement } from '../commerce';
 
 // Mock the Stripe components
 jest.mock('../stripe-react', () => ({