diff --git a/.changeset/x-yvp-sdk-header.md b/.changeset/x-yvp-sdk-header.md
new file mode 100644
index 00000000..d8634597
--- /dev/null
+++ b/.changeset/x-yvp-sdk-header.md
@@ -0,0 +1,12 @@
+---
+"@youversion/platform-core": minor
+"@youversion/platform-react-hooks": minor
+"@youversion/platform-react-ui": minor
+---
+
+Add `X-YVP-Sdk` header to every API call and let consumers override headers
+
+- New `X-YVP-Sdk: ReactSDK={version}` header sent on every request alongside `X-YVP-App-Key`. The version is imported directly from `packages/core/package.json` and inlined by the bundler at build time.
+- `SDK_VERSION`, `SDK_NAME`, and `SDK_VERSION_HEADER_NAME` exported from `@youversion/platform-core`.
+- `ApiConfig` gains an optional `additionalHeaders` map that is merged into every request. Keys here override the SDK's built-in headers, so wrappers (e.g. the React Native Expo SDK) can replace `X-YVP-Sdk` with their own identifier.
+- `YouVersionProvider` gains an `additionalHeaders` prop that flows through context to every hook-built `ApiClient`.
diff --git a/packages/core/src/YouVersionAPI.ts b/packages/core/src/YouVersionAPI.ts
index 8093221b..2e271453 100644
--- a/packages/core/src/YouVersionAPI.ts
+++ b/packages/core/src/YouVersionAPI.ts
@@ -1,10 +1,12 @@
 import { YouVersionPlatformConfiguration } from './YouVersionPlatformConfiguration';
+import { SDK_VERSION_HEADER_NAME, buildSdkVersionHeaderValue } from './version';
 
 export class YouVersionAPI {
   static addStandardHeaders(url: URL): Request {
     const headers: Record<string, string> = {
       Accept: 'application/json',
       'Content-Type': 'application/json',
+      [SDK_VERSION_HEADER_NAME]: buildSdkVersionHeaderValue(),
     };
 
     const appKey = YouVersionPlatformConfiguration.appKey;
diff --git a/packages/core/src/__tests__/client.test.ts b/packages/core/src/__tests__/client.test.ts
index 2df047c9..3d6090f6 100644
--- a/packages/core/src/__tests__/client.test.ts
+++ b/packages/core/src/__tests__/client.test.ts
@@ -128,6 +128,83 @@ describe('ApiClient', () => {
     });
   });
 
+  describe('default headers', () => {
+    it('should send X-YVP-Sdk header with ReactSDK identifier on every request', async () => {
+      let receivedHeader: string | null = null;
+      server.use(
+        http.get('https://test_placeholder.youversion.com/test', ({ request }) => {
+          receivedHeader = request.headers.get('x-yvp-sdk');
+          return HttpResponse.json({});
+        }),
+      );
+
+      await apiClient.get('/test');
+
+      expect(receivedHeader).toMatch(/^ReactSDK=.+$/);
+    });
+
+    it('should send X-YVP-App-Key header on every request', async () => {
+      let receivedAppKey: string | null = null;
+      server.use(
+        http.get('https://test_placeholder.youversion.com/test', ({ request }) => {
+          receivedAppKey = request.headers.get('x-yvp-app-key');
+          return HttpResponse.json({});
+        }),
+      );
+
+      await apiClient.get('/test');
+
+      expect(receivedAppKey).toBe('test-app');
+    });
+  });
+
+  describe('additionalHeaders', () => {
+    it('should send caller-supplied headers in addition to the built-in ones', async () => {
+      const client = new ApiClient({
+        apiHost: 'test_placeholder.youversion.com',
+        appKey: 'test-app',
+        additionalHeaders: { 'X-Custom': 'hello' },
+      });
+
+      let receivedCustom: string | null = null;
+      let receivedAppKey: string | null = null;
+      server.use(
+        http.get('https://test_placeholder.youversion.com/test', ({ request }) => {
+          receivedCustom = request.headers.get('x-custom');
+          receivedAppKey = request.headers.get('x-yvp-app-key');
+          return HttpResponse.json({});
+        }),
+      );
+
+      await client.get('/test');
+
+      expect(receivedCustom).toBe('hello');
+      expect(receivedAppKey).toBe('test-app');
+    });
+
+    it('should let additionalHeaders override the built-in X-YVP-Sdk header', async () => {
+      // Mirrors how a React Native Expo wrapper would replace the web SDK's
+      // identifier with its own.
+      const client = new ApiClient({
+        apiHost: 'test_placeholder.youversion.com',
+        appKey: 'test-app',
+        additionalHeaders: { 'X-YVP-Sdk': 'ReactNativeSDK=1.2.3' },
+      });
+
+      let receivedSdk: string | null = null;
+      server.use(
+        http.get('https://test_placeholder.youversion.com/test', ({ request }) => {
+          receivedSdk = request.headers.get('x-yvp-sdk');
+          return HttpResponse.json({});
+        }),
+      );
+
+      await client.get('/test');
+
+      expect(receivedSdk).toBe('ReactNativeSDK=1.2.3');
+    });
+  });
+
   describe('post', () => {
     it('should make POST request and return data', async () => {
       server.use(
diff --git a/packages/core/src/client.ts b/packages/core/src/client.ts
index c33b3249..9f0091bd 100644
--- a/packages/core/src/client.ts
+++ b/packages/core/src/client.ts
@@ -1,4 +1,5 @@
 import type { ApiConfig } from './types';
+import { SDK_VERSION_HEADER_NAME, buildSdkVersionHeaderValue } from './version';
 
 type PrimitiveQueryParam = string | number | boolean;
 type QueryParams = Record<string, PrimitiveQueryParam | PrimitiveQueryParam[]>;
@@ -34,6 +35,8 @@ export class ApiClient {
       'Content-Type': 'application/json',
       'X-YVP-App-Key': this.config.appKey,
       'X-YVP-Installation-Id': this.config.installationId || 'web-sdk-default',
+      [SDK_VERSION_HEADER_NAME]: buildSdkVersionHeaderValue(),
+      ...config.additionalHeaders,
     };
   }
 
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index 9a04f008..05374090 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -20,3 +20,4 @@ export {
   type TransformBibleHtmlOptions,
   type TransformedBibleHtml,
 } from './bible-html-transformer';
+export * from './version';
diff --git a/packages/core/src/types/index.ts b/packages/core/src/types/index.ts
index 6b523599..792bafb4 100644
--- a/packages/core/src/types/index.ts
+++ b/packages/core/src/types/index.ts
@@ -27,6 +27,13 @@ export interface ApiConfig {
   timeout?: number;
   installationId?: string;
   redirectUri?: string;
+  /**
+   * Extra HTTP headers merged into every request. Values here override the
+   * SDK's built-in headers when keys collide — useful for wrappers (e.g. the
+   * React Native Expo SDK) that need to replace `X-YVP-Sdk` with their own
+   * identifier.
+   */
+  additionalHeaders?: Record<string, string>;
 }
 
 export type SignInWithYouVersionPermissionValues =
diff --git a/packages/core/src/version.ts b/packages/core/src/version.ts
new file mode 100644
index 00000000..a731e36c
--- /dev/null
+++ b/packages/core/src/version.ts
@@ -0,0 +1,11 @@
+import pkg from '../package.json' with { type: 'json' };
+
+export const SDK_VERSION = pkg.version;
+
+export const SDK_NAME = 'ReactSDK';
+
+export const SDK_VERSION_HEADER_NAME = 'X-YVP-Sdk';
+
+export function buildSdkVersionHeaderValue(): string {
+  return `${SDK_NAME}=${SDK_VERSION}`;
+}
diff --git a/packages/hooks/src/context/YouVersionContext.tsx b/packages/hooks/src/context/YouVersionContext.tsx
index 9bdae246..ba8f418a 100644
--- a/packages/hooks/src/context/YouVersionContext.tsx
+++ b/packages/hooks/src/context/YouVersionContext.tsx
@@ -8,6 +8,7 @@ type YouVersionContextData = {
   installationId?: string;
   theme?: 'light' | 'dark';
   authEnabled?: boolean;
+  additionalHeaders?: Record<string, string>;
 };
 
 export const YouVersionContext = createContext<YouVersionContextData | null>(null);
diff --git a/packages/hooks/src/context/YouVersionProvider.tsx b/packages/hooks/src/context/YouVersionProvider.tsx
index 3e15baa5..56bc243c 100644
--- a/packages/hooks/src/context/YouVersionProvider.tsx
+++ b/packages/hooks/src/context/YouVersionProvider.tsx
@@ -1,7 +1,7 @@
 'use client';
 
 import type { PropsWithChildren, ReactNode } from 'react';
-import { lazy, Suspense, useEffect, useState } from 'react';
+import { lazy, Suspense, useEffect, useMemo, useState } from 'react';
 import { YouVersionContext } from './YouVersionContext';
 import { YouVersionPlatformConfiguration } from '@youversion/platform-core';
 
@@ -10,6 +10,13 @@ interface YouVersionProviderPropsBase {
   appKey: string;
   apiHost?: string;
   theme?: 'light' | 'dark' | 'system';
+  /**
+   * Extra HTTP headers to add to every API call made through hooks created by
+   * this provider. Values here override the SDK's built-in headers when keys
+   * collide — useful for wrappers (e.g. the React Native Expo SDK) that need
+   * to replace `X-YVP-Sdk` with their own identifier.
+   */
+  additionalHeaders?: Record<string, string>;
 }
 
 interface YouVersionProviderPropsWithAuth extends YouVersionProviderPropsBase {
@@ -55,9 +62,29 @@ function useResolvedTheme(theme: 'light' | 'dark' | 'system'): 'light' | 'dark'
 export function YouVersionProvider(
   props: PropsWithChildren<YouVersionProviderPropsWithAuth | YouVersionProviderPropsWithoutAuth>,
 ): React.ReactElement {
-  const { appKey, apiHost = 'api.youversion.com', includeAuth, theme = 'light', children } = props;
+  const {
+    appKey,
+    apiHost = 'api.youversion.com',
+    includeAuth,
+    theme = 'light',
+    additionalHeaders,
+    children,
+  } = props;
   const resolvedTheme = useResolvedTheme(theme);
 
+  // Stable identity so memoized consumers (hooks that build ApiClient) don't
+  // rebuild when the parent re-renders with an inline object literal. Sort
+  // entries before serialising so key-insertion-order differences don't
+  // invalidate the memo for headers that are semantically identical.
+  const additionalHeadersKey = additionalHeaders
+    ? JSON.stringify(Object.entries(additionalHeaders).sort(([a], [b]) => a.localeCompare(b)))
+    : null;
+  const stableAdditionalHeaders = useMemo(
+    () => additionalHeaders,
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    [additionalHeadersKey],
+  );
+
   // Sync props to YouVersionPlatformConfiguration so any code that reads the
   // static config (e.g. core's auth/PKCE flows, called from user actions) sees
   // the same values. Children that read via context get the prop directly
@@ -73,6 +100,7 @@ export function YouVersionProvider(
     installationId: YouVersionPlatformConfiguration.installationId,
     theme: resolvedTheme,
     authEnabled: !!includeAuth,
+    additionalHeaders: stableAdditionalHeaders,
   };
 
   if (includeAuth) {
diff --git a/packages/hooks/src/useBibleClient.test.tsx b/packages/hooks/src/useBibleClient.test.tsx
index 764b5738..9489ee34 100644
--- a/packages/hooks/src/useBibleClient.test.tsx
+++ b/packages/hooks/src/useBibleClient.test.tsx
@@ -96,6 +96,30 @@ describe('useBibleClient', () => {
     });
   });
 
+  it('should pass additionalHeaders from context into ApiClient config', () => {
+    const additionalHeaders = { 'X-YVP-Sdk': 'ReactNativeSDK=1.2.3' };
+
+    const wrapper = ({ children }: { children: ReactNode }) => (
+      <YouVersionContext.Provider
+        value={{
+          appKey: 'test-app-key',
+          additionalHeaders,
+        }}
+      >
+        {children}
+      </YouVersionContext.Provider>
+    );
+
+    renderHook(() => useBibleClient(), { wrapper });
+
+    expect(ApiClient).toHaveBeenCalledWith(
+      expect.objectContaining({
+        appKey: 'test-app-key',
+        additionalHeaders,
+      }),
+    );
+  });
+
   it('should throw error when appKey is null', () => {
     const wrapper = ({ children }: { children: ReactNode }) => (
       <YouVersionContext.Provider
diff --git a/packages/hooks/src/useBibleClient.ts b/packages/hooks/src/useBibleClient.ts
index 5bd77259..1673f47f 100644
--- a/packages/hooks/src/useBibleClient.ts
+++ b/packages/hooks/src/useBibleClient.ts
@@ -19,7 +19,8 @@ export function useBibleClient(): BibleClient {
         appKey: context.appKey,
         apiHost: context.apiHost,
         installationId: context.installationId,
+        additionalHeaders: context.additionalHeaders,
       }),
     );
-  }, [context?.apiHost, context?.appKey, context?.installationId]);
+  }, [context?.apiHost, context?.appKey, context?.installationId, context?.additionalHeaders]);
 }
diff --git a/packages/hooks/src/useHighlights.ts b/packages/hooks/src/useHighlights.ts
index e0250698..448cd399 100644
--- a/packages/hooks/src/useHighlights.ts
+++ b/packages/hooks/src/useHighlights.ts
@@ -37,9 +37,10 @@ export function useHighlights(
         appKey: context.appKey,
         apiHost: context.apiHost,
         installationId: context.installationId,
+        additionalHeaders: context.additionalHeaders,
       }),
     );
-  }, [context?.apiHost, context?.appKey, context?.installationId]);
+  }, [context?.apiHost, context?.appKey, context?.installationId, context?.additionalHeaders]);
 
   const { data, loading, error, refetch } = useApiData<Collection<Highlight>>(
     () => highlightsClient.getHighlights(options),
diff --git a/packages/hooks/src/useLanguageClient.ts b/packages/hooks/src/useLanguageClient.ts
index fa740769..4fa6bd25 100644
--- a/packages/hooks/src/useLanguageClient.ts
+++ b/packages/hooks/src/useLanguageClient.ts
@@ -19,7 +19,8 @@ export function useLanguagesClient(): LanguagesClient {
         appKey: context.appKey,
         apiHost: context.apiHost,
         installationId: context.installationId,
+        additionalHeaders: context.additionalHeaders,
       }),
     );
-  }, [context?.apiHost, context?.appKey, context?.installationId]);
+  }, [context?.apiHost, context?.appKey, context?.installationId, context?.additionalHeaders]);
 }
diff --git a/packages/ui/src/components/YouVersionProvider.test.tsx b/packages/ui/src/components/YouVersionProvider.test.tsx
new file mode 100644
index 00000000..69ecc7ff
--- /dev/null
+++ b/packages/ui/src/components/YouVersionProvider.test.tsx
@@ -0,0 +1,48 @@
+/**
+ * @vitest-environment jsdom
+ */
+import { describe, it, expect, vi } from 'vitest';
+import { render } from '@testing-library/react';
+import React from 'react';
+import { YouVersionProvider } from '@/components/YouVersionProvider';
+
+const baseProviderMock =
+  vi.fn<(props: Record<string, unknown> & { children?: React.ReactNode }) => React.ReactElement>();
+baseProviderMock.mockImplementation(({ children }) => <>{children}</>);
+
+vi.mock('@youversion/platform-react-hooks', () => ({
+  YouVersionProvider: (props: Record<string, unknown> & { children?: React.ReactNode }) =>
+    baseProviderMock(props),
+  useYVAuth: vi.fn(),
+}));
+
+describe('UI YouVersionProvider', () => {
+  it('forwards additionalHeaders to the underlying hooks provider', () => {
+    const additionalHeaders = { 'X-YVP-Sdk': 'ReactNativeSDK=1.2.3' };
+
+    render(
+      <YouVersionProvider appKey="test-key" additionalHeaders={additionalHeaders}>
+        <div data-testid="child">hello</div>
+      </YouVersionProvider>,
+    );
+
+    expect(baseProviderMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        appKey: 'test-key',
+        additionalHeaders,
+      }),
+    );
+  });
+
+  it('omits additionalHeaders when not provided', () => {
+    render(
+      <YouVersionProvider appKey="test-key">
+        <div data-testid="child">hello</div>
+      </YouVersionProvider>,
+    );
+
+    const lastCall = baseProviderMock.mock.calls.at(-1)?.[0] as Record<string, unknown>;
+    expect(lastCall?.appKey).toBe('test-key');
+    expect(lastCall?.additionalHeaders).toBeUndefined();
+  });
+});