diff --git a/tests/sdk.test.ts b/tests/sdk.test.ts
index 96c40b3..45a65bf 100644
--- a/tests/sdk.test.ts
+++ b/tests/sdk.test.ts
@@ -1,5 +1,6 @@
 import { NotificationAPIClientSDK } from '../lib/client';
 import { api } from '../lib/api';
+import { PostUserRequest } from '../lib/interfaces';
 
 // Mock the fetch function
 global.fetch = jest.fn();
@@ -42,7 +43,146 @@ describe('NotificationAPIClientSDK', () => {
       expect.any(Object)
     );
   });
+  test('getInAppNotifications should correctly reduce oldestReceived', async () => {
+    const mockResponse = {
+      json: jest.fn().mockResolvedValue({
+        notifications: [
+          { id: '1', date: '2023-01-02T00:00:00Z' },
+          { id: '2', date: '2023-01-01T00:00:00Z' },
+          { id: '3', date: '2023-01-03T00:00:00Z' }
+        ]
+      })
+    };
+    (global.fetch as jest.Mock).mockResolvedValue(mockResponse);
+
+    const sdk = NotificationAPIClientSDK.init({
+      userId: 'testUser',
+      clientId: 'testClient'
+    });
+
+    const result = await sdk.getInAppNotifications({
+      before: '2023-01-04T00:00:00Z'
+    });
+
+    expect(result.oldestReceived).toBe('2023-01-01T00:00:00Z');
+  });
+  test('updateInAppNotifications should set archived to null when archived is false', async () => {
+    const mockResponse = {
+      json: jest.fn().mockResolvedValue({})
+    };
+    (global.fetch as jest.Mock).mockResolvedValue(mockResponse);
+
+    const sdk = NotificationAPIClientSDK.init({
+      userId: 'testUser',
+      clientId: 'testClient'
+    });
+
+    await sdk.updateInAppNotifications({
+      ids: ['notification1', 'notification2'],
+      archived: false
+    });
+
+    expect(global.fetch).toHaveBeenCalledWith(
+      'https://api.notificationapi.com/testClient/users/testUser/notifications/INAPP_WEB',
+      expect.objectContaining({
+        method: 'PATCH',
+        body: JSON.stringify({
+          trackingIds: ['notification1', 'notification2'],
+          archived: null
+        }),
+        headers: {
+          Authorization: expect.any(String)
+        }
+      })
+    );
+  });
+  test('updateInAppNotifications should set clicked to null when clicked is false', async () => {
+    const mockResponse = {
+      json: jest.fn().mockResolvedValue({})
+    };
+    (global.fetch as jest.Mock).mockResolvedValue(mockResponse);
+
+    const sdk = NotificationAPIClientSDK.init({
+      userId: 'testUser',
+      clientId: 'testClient'
+    });
+
+    await sdk.updateInAppNotifications({
+      ids: ['notification1', 'notification2'],
+      clicked: false
+    });
 
+    expect(global.fetch).toHaveBeenCalledWith(
+      'https://api.notificationapi.com/testClient/users/testUser/notifications/INAPP_WEB',
+      expect.objectContaining({
+        method: 'PATCH',
+        body: JSON.stringify({
+          trackingIds: ['notification1', 'notification2'],
+          clicked: null
+        }),
+        headers: {
+          Authorization: expect.any(String)
+        }
+      })
+    );
+  });
+  test('updateInAppNotifications should set opened to current date when opened is true', async () => {
+    const mockResponse = {
+      json: jest.fn().mockResolvedValue({})
+    };
+    (global.fetch as jest.Mock).mockResolvedValue(mockResponse);
+
+    const sdk = NotificationAPIClientSDK.init({
+      userId: 'testUser',
+      clientId: 'testClient'
+    });
+
+    await sdk.updateInAppNotifications({
+      ids: ['notification1', 'notification2'],
+      opened: true
+    });
+
+    expect(global.fetch).toHaveBeenCalledWith(
+      'https://api.notificationapi.com/testClient/users/testUser/notifications/INAPP_WEB',
+      expect.objectContaining({
+        method: 'PATCH',
+        body: expect.stringContaining('"opened":"'),
+        headers: {
+          Authorization: expect.any(String)
+        }
+      })
+    );
+  });
+  test('updateInAppNotifications should set opened to null when opened is false', async () => {
+    const mockResponse = {
+      json: jest.fn().mockResolvedValue({})
+    };
+    (global.fetch as jest.Mock).mockResolvedValue(mockResponse);
+
+    const sdk = NotificationAPIClientSDK.init({
+      userId: 'testUser',
+      clientId: 'testClient'
+    });
+
+    await sdk.updateInAppNotifications({
+      ids: ['notification1', 'notification2'],
+      opened: false
+    });
+
+    expect(global.fetch).toHaveBeenCalledWith(
+      'https://api.notificationapi.com/testClient/users/testUser/notifications/INAPP_WEB',
+      expect.objectContaining({
+        method: 'PATCH',
+        body: JSON.stringify({
+          trackingIds: ['notification1', 'notification2'],
+          opened: null
+        }),
+        headers: {
+          Authorization: expect.any(String)
+        }
+      })
+    );
+  });
   test('updateInAppNotifications should call api with correct parameters', async () => {
     const mockResponse = {
       json: jest.fn().mockResolvedValue({})
@@ -132,6 +272,72 @@ describe('NotificationAPIClientSDK', () => {
       })
     );
   });
+
+  test('identify should call api with correct parameters', async () => {
+    const mockResponse = {
+      json: jest.fn().mockResolvedValue({ preferences: [] })
+    };
+    (global.fetch as jest.Mock).mockResolvedValue(mockResponse);
+
+    const sdk = NotificationAPIClientSDK.init({
+      userId: 'testUser',
+      clientId: 'testClient'
+    });
+    const params: PostUserRequest = {
+      id: 'testUser',
+      email: 'userTestEmail@notificationapi.com'
+    };
+    await sdk.identify(params);
+
+    expect(global.fetch).toHaveBeenCalledWith(
+      expect.stringContaining(
+        'https://api.notificationapi.com/testClient/users/testUser/'
+      ),
+      expect.objectContaining({
+        method: 'POST',
+        body: JSON.stringify(params)
+      })
+    );
+  });
+  test('identify should not call api with wrong parameters', async () => {
+    const mockResponse = {
+      json: jest.fn().mockResolvedValue({ preferences: [] })
+    };
+    (global.fetch as jest.Mock).mockResolvedValue(mockResponse);
+
+    const sdk = NotificationAPIClientSDK.init({
+      userId: 'testUser',
+      clientId: 'testClient'
+    });
+    const params: PostUserRequest = {
+      id: 'testUser2',
+      email: 'userTestEmail@notificationapi.com'
+    };
+    await expect(sdk.identify(params)).rejects.toThrow(
+      'The id in the parameters does not match the initialized userId.'
+    );
+  });
+  test('getUserAccountMetadata should call api with correct parameters', async () => {
+    const mockResponse = {
+      json: jest.fn().mockResolvedValue({ preferences: [] })
+    };
+    (global.fetch as jest.Mock).mockResolvedValue(mockResponse);
+
+    const sdk = NotificationAPIClientSDK.init({
+      userId: 'testUser',
+      clientId: 'testClient'
+    });
+    await sdk.getUserAccountMetadata();
+
+    expect(global.fetch).toHaveBeenCalledWith(
+      expect.stringContaining(
+        'https://api.notificationapi.com/testClient/users/testUser/account_metadata'
+      ),
+      expect.objectContaining({
+        method: 'GET'
+      })
+    );
+  });
 });
 
 describe('api function', () => {
@@ -180,4 +386,20 @@ describe('api function', () => {
 
     expect(result).toEqual('error');
   });
+  test('should return undefined if response is not JSON', async () => {
+    const mockResponse = {
+      json: jest.fn().mockRejectedValue(new Error('Invalid JSON'))
+    };
+    (global.fetch as jest.Mock).mockResolvedValue(mockResponse);
+
+    const result = await api(
+      'GET',
+      'api.notificationapi.com',
+      'testResource',
+      'testClient',
+      'testUser'
+    );
+
+    expect(result).toBeUndefined();
+  });
 });