clerk · chriscanin · Jan 22, 2026 · Jan 22, 2026 · Jan 22, 2026 · wobsoriano
diff --git a/.changeset/kadi-env-var-fix.md b/.changeset/kadi-env-var-fix.md
@@ -0,0 +1,5 @@
+---
+"@clerk/expo": major
+---
+
+fix(expo): Make publishableKey prop required and remove env var fallbacks
-fix(expo): Make publishableKey prop required and remove env var fallbacks
+The `publishableKey` prop is now required in `ClerkProvider`. Previously, the prop was optional and would fall back to `EXPO_PUBLIC_CLERK_PUBLISHABLE_KEY` or `CLERK_PUBLISHABLE_KEY` environment variables.
+
+Environment variables inside `node_modules` are not inlined during production builds in React Native/Expo, which could cause apps to crash in production when the publishable key is undefined.
+
+You must now explicitly pass the `publishableKey` prop to `ClerkProvider`:
+
+```tsx
+const publishableKey = process.env.EXPO_PUBLIC_CLERK_PUBLISHABLE_KEY!;
+
+<ClerkProvider publishableKey={publishableKey}>
+  {/* Your app */}
+</ClerkProvider>
-fix(expo): Make publishableKey prop required and remove env var fallbacks
+The `publishableKey` prop is now required in `ClerkProvider`. Previously, the prop was optional and would fall back to `EXPO_PUBLIC_CLERK_PUBLISHABLE_KEY` or `CLERK_PUBLISHABLE_KEY` environment variables.
+
+Environment variables inside `node_modules` are not inlined during production builds in React Native/Expo, which could cause apps to crash in production when the publishable key is undefined.
+
+You must now explicitly pass the `publishableKey` prop to `ClerkProvider`:
+
+```tsx
+const publishableKey = process.env.EXPO_PUBLIC_CLERK_PUBLISHABLE_KEY!;
+
+<ClerkProvider publishableKey={publishableKey}>
+  {/* Your app */}
+</ClerkProvider>
diff --git a/packages/expo/src/provider/ClerkProvider.tsx b/packages/expo/src/provider/ClerkProvider.tsx
@@ -14,10 +14,17 @@ export type ClerkProviderProps<TUi extends Ui = Ui> = Omit<
   'publishableKey'
 > & {
   /**
-   * Used to override the default EXPO_PUBLIC_CLERK_PUBLISHABLE_KEY env variable if needed.
-   * This is optional for Expo as the ClerkProvider will automatically use the EXPO_PUBLIC_CLERK_PUBLISHABLE_KEY env variable if it exists.
+   * Your Clerk publishable key, available in the Clerk Dashboard.
+   * This is required for React Native / Expo apps. Environment variables inside node_modules
+   * are not inlined during production builds, so the key must be passed explicitly.
+   *
+   * @example
+   * ```tsx
+   * const publishableKey = process.env.EXPO_PUBLIC_CLERK_PUBLISHABLE_KEY!;
+   * <ClerkProvider publishableKey={publishableKey}>
+   * ```
    */
-  publishableKey?: string;
+  publishableKey: string;
   /**
    * The token cache is used to persist the active user's session token. Clerk stores this token in memory by default, however it is recommended to use a token cache for production applications.
    * @see https://clerk.com/docs/quickstarts/expo#configure-the-token-cache-with-expo
@@ -53,7 +60,7 @@ export function ClerkProvider<TUi extends Ui = Ui>(props: ClerkProviderProps<TUi
     __experimental_resourceCache,
     ...rest
   } = props;
-  const pk = publishableKey || process.env.EXPO_PUBLIC_CLERK_PUBLISHABLE_KEY || process.env.CLERK_PUBLISHABLE_KEY || '';
+  const pk = publishableKey;
 
   if (isWeb()) {
     // This is needed in order for useOAuth to work correctly on web.

diff --git a/packages/expo/src/provider/singleton/createClerkInstance.ts b/packages/expo/src/provider/singleton/createClerkInstance.ts
@@ -30,7 +30,7 @@ let __internal_clerk: HeadlessBrowserClerk | BrowserClerk | undefined;
 export function createClerkInstance(ClerkClass: typeof Clerk) {
   return (options?: BuildClerkOptions): HeadlessBrowserClerk | BrowserClerk => {
     const {
-      publishableKey = process.env.EXPO_PUBLIC_CLERK_PUBLISHABLE_KEY || process.env.CLERK_PUBLISHABLE_KEY || '',
+      publishableKey = '',
       tokenCache = MemoryTokenCache,
       __experimental_resourceCache: createResourceCache,
     } = options || {};