diff --git a/src/__tests__/index.test.tsx b/src/__tests__/index.test.tsx
index bf84291..9d00c2c 100644
--- a/src/__tests__/index.test.tsx
+++ b/src/__tests__/index.test.tsx
@@ -1 +1,101 @@
-it.todo('write a test');
+import { NativeModules, Platform } from 'react-native';
+import { Zendesk } from '../index';
+import type { StartChatOptions, ZendeskConfig } from '../ZendeskUnified.types';
+
+jest.mock('react-native', () => {
+  const reactNative = jest.requireActual('react-native');
+
+  reactNative.NativeModules.ZendeskUnified = {
+    initialize: jest.fn(),
+    healthCheck: jest.fn(() => Promise.resolve('OK')),
+    setAnonymousIdentity: jest.fn(() => Promise.resolve(true)),
+    setIdentity: jest.fn(() => Promise.resolve(true)),
+    openHelpCenter: jest.fn(() => Promise.resolve()),
+    openTicket: jest.fn(() => Promise.resolve()),
+    openNewTicket: jest.fn(() => Promise.resolve()),
+    listTickets: jest.fn(() => Promise.resolve()),
+    openArticle: jest.fn(() => Promise.resolve()),
+    setHelpCenterLocaleOverride: jest.fn(() => Promise.resolve()),
+    changeTheme: jest.fn(() => Promise.resolve()),
+    initializeChat: jest.fn(() => Promise.resolve()),
+    startChat: jest.fn(() => Promise.resolve()),
+    startAnswerBot: jest.fn(() => Promise.resolve()),
+  };
+
+  return reactNative;
+});
+
+const ZendeskUnified = NativeModules.ZendeskUnified;
+
+describe('Zendesk class', () => {
+  const zendeskConfig: ZendeskConfig = {
+    appId: 'appId',
+    clientId: 'clientId',
+    zendeskUrl: 'zendeskUrl',
+    accountKey: 'accountKey',
+  };
+
+  const zendesk = new Zendesk(zendeskConfig);
+
+  it('should initialize ZendeskUnified with the provided config', () => {
+    expect(zendesk).toBeDefined();
+    expect(zendesk instanceof Zendesk).toBe(true);
+    expect(ZendeskUnified.initialize).toHaveBeenCalledWith(zendeskConfig);
+  });
+
+  it('should perform health check', async () => {
+    const result = await zendesk.healthCheck();
+    expect(result).toEqual('OK');
+  });
+
+  it('should set anonymous identity', async () => {
+    const options = {};
+    const result = await zendesk.setAnonymousIdentity(options);
+    expect(result).toBe(true);
+  });
+
+  it('should set identity', async () => {
+    const jwt = 'mock-jwt';
+    const result = await zendesk.setIdentity(jwt);
+    expect(result).toBe(true);
+  });
+
+  it('should open an article', async () => {
+    const articleId = 123;
+    await zendesk.openArticle(articleId);
+    expect(ZendeskUnified.openArticle).toHaveBeenCalledWith(
+      Platform.OS === 'ios' ? articleId.toString() : articleId
+    );
+  });
+
+  it('should set Help Center locale override', async () => {
+    const locale = 'en_US';
+    await zendesk.setHelpCenterLocaleOverride(locale);
+    expect(ZendeskUnified.setHelpCenterLocaleOverride).toHaveBeenCalledWith(
+      locale
+    );
+  });
+
+  it('should change theme', async () => {
+    const color = 'blue';
+    await zendesk.changeTheme(color);
+    expect(ZendeskUnified.changeTheme).toHaveBeenCalledWith(color);
+  });
+
+  it('should initialize chat', async () => {
+    const accountKey = 'chat-account-key';
+    await zendesk.initializeChat(accountKey);
+    expect(ZendeskUnified.initializeChat).toHaveBeenCalledWith(accountKey);
+  });
+
+  it('should start chat', async () => {
+    const options: StartChatOptions = { botName: 'bot-name' };
+    await zendesk.startChat(options);
+    expect(ZendeskUnified.startChat).toHaveBeenCalledWith(options);
+  });
+
+  it('should start Answer Bot', async () => {
+    await zendesk.startAnswerBot();
+    expect(ZendeskUnified.startAnswerBot).toHaveBeenCalled();
+  });
+});