diff --git a/.nycrc b/.nycrc
index 80f4ea0..f4cb085 100644
--- a/.nycrc
+++ b/.nycrc
@@ -3,7 +3,7 @@
   "check-coverage": true,
   "all": true,
   "include": ["src/**/*.ts"],
-  "exclude": ["src/index.ts", "**/*.spec.ts"],
+  "exclude": ["src/onspringApiSdk.ts", "**/*.spec.ts"],
   "reporter": ["html", "lcov", "text", "text-summary"],
   "report-dir": "coverage"
 }
diff --git a/src/models/ApiResponse.ts b/src/models/ApiResponse.ts
index cac1611..a098815 100644
--- a/src/models/ApiResponse.ts
+++ b/src/models/ApiResponse.ts
@@ -1,4 +1,5 @@
 import { App } from './App';
+import { CollectionResponse } from './CollectionResponse';
 import { GetPagedAppsResponse } from './GetPagedAppsResponse';
 
 /**
@@ -44,13 +45,13 @@ export class ApiResponse<T> {
    * @returns {ApiResponse<GetPagedAppsResponse>} - An ApiResponse<GetPagedAppsResponse>.
    */
   public AsGetPagedAppsResponseType(): ApiResponse<GetPagedAppsResponse> {
-    var apiResponse = this as ApiResponse<any>;
+    const apiResponse = this as ApiResponse<any>;
 
-    var apps = apiResponse.data.items.map((item: any) => {
+    const apps = apiResponse.data.items.map((item: any) => {
       return new App(item.href, item.id, item.name);
     });
 
-    var getAppsPagedResponse = new GetPagedAppsResponse(
+    const getAppsPagedResponse = new GetPagedAppsResponse(
       apps,
       apiResponse.data.pageNumber,
       apiResponse.data.pageSize,
@@ -65,10 +66,14 @@ export class ApiResponse<T> {
     );
   }
 
+  /**
+   * @method AsAppType - Converts the ApiResponse to an ApiResponse<App>.
+   * @returns {ApiResponse<App>} - An ApiResponse<App>.
+   */
   AsAppType(): ApiResponse<App> {
-    var apiResponse = this as ApiResponse<any>;
+    const apiResponse = this as ApiResponse<any>;
 
-    var app = new App(
+    const app = new App(
       apiResponse.data.href,
       apiResponse.data.id,
       apiResponse.data.name
@@ -80,4 +85,27 @@ export class ApiResponse<T> {
       app
     );
   }
+
+  /**
+   * @method AsAppCollectionType - Converts the ApiResponse to an ApiResponse<CollectionResponse<App>>.
+   * @returns {ApiResponse<CollectionResponse<App>>} - An ApiResponse<CollectionResponse<App>>.
+   */
+  AsAppCollectionType(): ApiResponse<CollectionResponse<App>> {
+    const apiResponse = this as ApiResponse<any>;
+
+    const apps = apiResponse.data.items.map((item: any) => {
+      return new App(item.href, item.id, item.name);
+    });
+
+    const collectionResponse = new CollectionResponse<App>(
+      apiResponse.data.count,
+      apps
+    );
+
+    return new ApiResponse<CollectionResponse<App>>(
+      apiResponse.statusCode,
+      apiResponse.message,
+      collectionResponse
+    );
+  }
 }
diff --git a/src/models/ArgumentValidator.ts b/src/models/ArgumentValidator.ts
index a27cf20..b7aceae 100644
--- a/src/models/ArgumentValidator.ts
+++ b/src/models/ArgumentValidator.ts
@@ -3,6 +3,7 @@
  */
 export class ArgumentValidator {
   /**
+   * @method isNullOrWhiteSpace - Determines if the value is null, undefined, or a string that contains only whitespace characters.
    * @param {string} value - The value to validate.
    * @returns {boolean} - True if the value is null, undefined, or a string that contains only whitespace characters; otherwise, false.
    */
@@ -11,6 +12,7 @@ export class ArgumentValidator {
   }
 
   /**
+   * @method isValidUrl - Determines if the value is a valid URL.
    * @param {string} value - The value to validate.
    * @returns {boolean} - True if the value is a valid URL; otherwise, false.
    */
@@ -31,6 +33,7 @@ export class ArgumentValidator {
   }
 
   /**
+   * @method isValidPageSize - Determines if the value is a valid page size.
    * @param {number} value - The value to validate.
    * @returns {boolean} - True if the value is a valid page size; otherwise, false.
    * @remarks - A valid page size is a number greater than 0 and less than or equal to 1000.
@@ -44,6 +47,7 @@ export class ArgumentValidator {
   }
 
   /**
+   * @method isValidPageNumber - Determines if the value is a valid page number.
    * @param {number} value - The value to validate.
    * @returns {boolean} - True if the value is a valid page number; otherwise, false.
    * @remarks - A valid page number is a number greater than 0.
diff --git a/src/models/CollectionResponse.ts b/src/models/CollectionResponse.ts
index fcaaf9a..e7bde20 100644
--- a/src/models/CollectionResponse.ts
+++ b/src/models/CollectionResponse.ts
@@ -10,7 +10,7 @@ export class CollectionResponse<T> {
   /**
    * @property {T} items - The items in the collection.
    */
-  public items: T;
+  public items: T[];
 
   /**
    * @constructor - Creates a new instance of the CollectionResponse class.
@@ -18,7 +18,7 @@ export class CollectionResponse<T> {
    * @param {T} items - The items in the collection.
    * @returns {CollectionResponse<T>} - A new instance of the CollectionResponse.
    */
-  constructor(count: number, items: T) {
+  constructor(count: number, items: T[]) {
     this.count = count;
     this.items = items;
   }
diff --git a/src/models/EndpointFactory.ts b/src/models/EndpointFactory.ts
index 4317b01..d8e6940 100644
--- a/src/models/EndpointFactory.ts
+++ b/src/models/EndpointFactory.ts
@@ -5,6 +5,7 @@ import { PagingRequest } from './PagingRequest';
  */
 export class EndpointFactory {
   /**
+   * @method getPingEndpoint - Gets the ping endpoint.
    * @returns {string} - The ping endpoint.
    */
   public static getPingEndpoint(): string {
@@ -12,6 +13,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getAppsEndpoint - Gets the apps endpoint.
    * @param {PagingRequest} pagingRequest - Pagination information to use as query params in the endpoint string.
    * @returns {string} - The apps endpoint.
    */
@@ -20,6 +22,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getAppByIdEndpoint - Gets the app by id endpoint.
    * @param {number} id - The id of the app.
    * @returns {string} - The app by id endpoint.
    */
@@ -28,6 +31,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getAppsByIdsEndpoint - Gets the apps by ids endpoint.
    * @returns {string} - The apps by ids endpoint.
    */
   public static getAppsByIdsEndpoint(): string {
@@ -35,6 +39,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getRecordsEndpoint - Gets the records endpoint.
    * @param {number} id - The id of the field.
    * @returns {string} - The field by id endpoint.
    */
@@ -43,6 +48,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getFieldsByIdsEndpoint - Gets the fields by ids endpoint.
    * @returns {string} - The fields by ids endpoint.
    */
   public static getFieldsByIdsEndpoint(): string {
@@ -50,6 +56,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getFieldsByAppIdEndpoint - Gets the fields by app id endpoint.
    * @param {number} id - The id of the app.
    * @returns {string} - The fields by app id endpoint.
    */
@@ -58,6 +65,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getRecordsEndpoint - Gets the records endpoint.
    * @param {number} recordId - The id of the record.
    * @param {number} fieldId - The id of the field.
    * @param {number} fileId - The id of the file.
@@ -72,6 +80,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getDeleteFileByIdEndpoint - Gets the delete file by id endpoint.
    * @param {number} recordId - The id of the record.
    * @param {number} fieldId - The id of the field.
    * @param {number} fileId - The id of the file.
@@ -86,6 +95,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getFileByIdEndpoint - Gets the file by id endpoint.
    * @param {number} recordId - The id of the record.
    * @param {number} fieldId - The id of the field.
    * @param {number} fileId - The id of the file.
@@ -100,6 +110,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getSaveFileEndpoint - Gets the save file endpoint.
    * @returns {string} - The save file endpoint.
    */
   public static getSaveFileEndpoint(): string {
@@ -107,6 +118,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getAddOrUpdateListItemEndpoint - Gets the add or update list item endpoint.
    * @param {number} listId - The id of the list.
    * @returns {string} - The add or update list item endpoint.
    */
@@ -115,6 +127,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getDeleteListItemEndpoint - Gets the delete list item endpoint.
    * @param {number} listId - The id of the list.
    * @param {string} itemId - The id of the list item.
    * @returns {string} - The delete list item endpoint.
@@ -127,6 +140,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getRecordsByAppIdEndpoint - Gets the get records by app id endpoint.
    * @param {number} appId - The id of the app.
    * @returns {string} - The get records by app id endpoint.
    */
@@ -135,6 +149,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getRecordByIdEndpoint - Gets the get record by id endpoint.
    * @param {number} appId - The id of the app.
    * @param {number} recordId - The id of the record.
    * @returns {string} - The get record by id endpoint.
@@ -144,6 +159,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getDeleteRecordByIdEndpoint - Gets the delete record by id endpoint.
    * @param {number} appId - The id of the app.
    * @param {number} recordId - The id of the record.
    * @returns {string} - The delete record by id endpoint.
@@ -156,6 +172,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getRecordsByIdsEndpoint - Gets the get records by ids endpoint.
    * @returns {string} - The get records by ids endpoint.
    */
   public static getRecordsByIdsEndpoint(): string {
@@ -163,6 +180,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getQueryRecordsEndpoint - Gets the query records endpoint.
    * @returns {string} - The query records endpoint.
    */
   public static getQueryRecordsEndpoint(): string {
@@ -170,6 +188,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getAddOrUpdateRecordEndpoint - Gets the add or update record endpoint.
    * @returns {string} - The add or update record endpoint.
    */
   public static getAddOrUpdateRecordEndpoint(): string {
@@ -177,6 +196,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getDeleteRecordsByIdsEndpoint - Gets the delete records by ids endpoint.
    * @returns {string} - The delete records by ids endpoint.
    */
   public static getDeleteRecordsByIdsEndpoint(): string {
@@ -184,6 +204,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getReportByIdEndpoint - Gets the get report by id endpoint.
    * @param {number} reportId - The id of the report.
    * @returns {string} - The get report by id endpoint.
    */
@@ -192,6 +213,7 @@ export class EndpointFactory {
   }
 
   /**
+   * @method getReportsByAppIdEndpoint - Gets the get reports by app id endpoint.
    * @param {number} appId - The id of the app.
    * @returns {string} - The get reports by app id endpoint.
    */
diff --git a/src/models/GetPagedAppsResponse.ts b/src/models/GetPagedAppsResponse.ts
index 375dcf0..a187c87 100644
--- a/src/models/GetPagedAppsResponse.ts
+++ b/src/models/GetPagedAppsResponse.ts
@@ -1,7 +1,19 @@
 import { PagedResponse } from './PagedResponse';
 import { App } from './App';
 
+/**
+ * @class GetPagedAppsResponse - A paged response model for the GetApps method.
+ */
 export class GetPagedAppsResponse extends PagedResponse<App> {
+  /**
+   * @constructor - Creates a new instance of the GetPagedAppsResponse class.
+   * @param {App[]} items - The items in the collection.
+   * @param {number} pageNumber - The page number of the response.
+   * @param {number} pageSize - The page size of the response.
+   * @param {number} totalPages - The total number of pages in the response.
+   * @param {number} totalRecords - The total number of records in the response.
+   * @returns {GetPagedAppsResponse} - A new instance of the GetPagedAppsResponse class.
+   */
   constructor(
     items: App[],
     pageNumber: number,
diff --git a/src/models/OnspringClient.ts b/src/models/OnspringClient.ts
index 46b41e4..5635410 100644
--- a/src/models/OnspringClient.ts
+++ b/src/models/OnspringClient.ts
@@ -7,14 +7,12 @@ import { ApiResponse } from './ApiResponse';
 import { PagingRequest } from './PagingRequest';
 import { GetPagedAppsResponse } from './GetPagedAppsResponse';
 import { App } from './App';
+import { CollectionResponse } from './CollectionResponse';
 
 /**
  * @class OnspringClient - A client that can communicate with the Onspring API.
  */
 export class OnspringClient {
-  getAppsByIds(getAppsByIds: any) {
-    throw new Error('Method not implemented.');
-  }
   /**
    * @readonly {AxiosInstance} client - The axios instance that will be used to make requests to the Onspring API.
    */
@@ -58,9 +56,9 @@ export class OnspringClient {
   }
 
   /**
-   *
+   * @method getApps - Gets a paged list of apps.
    * @param pagingRequest - The paging request that will be used to get the apps.
-   * @returns
+   * @returns - A promise that resolves to an ApiResponse of type GetPagedAppsResponse.
    */
   public async getApps(
     pagingRequest: PagingRequest = new PagingRequest(1, 50)
@@ -76,6 +74,11 @@ export class OnspringClient {
     return apiResponse.AsGetPagedAppsResponseType();
   }
 
+  /**
+   * @method getAppById - Gets an app by its id.
+   * @param appId - The id of the app to get.
+   * @returns - A promise that resolves to an ApiResponse of type App.
+   */
   public async getAppById(appId: number): Promise<ApiResponse<App>> {
     const endpoint = EndpointFactory.getAppByIdEndpoint(appId);
 
@@ -88,9 +91,28 @@ export class OnspringClient {
     return apiResponse.AsAppType();
   }
 
+  /**
+   * @method getAppsByIds - Gets a list of apps by their ids.
+   * @param getAppsByIds - The ids of the apps to get.
+   * @returns - A promise that resolves to an ApiResponse of type CollectionResponse<App>.
+   */
+  public async getAppsByIds(
+    getAppsByIds: number[]
+  ): Promise<ApiResponse<CollectionResponse<App>>> {
+    const endpoint = EndpointFactory.getAppsByIdsEndpoint();
+    const apiResponse = await this.post<any>(endpoint, getAppsByIds);
+
+    if (apiResponse.isSuccessful === false) {
+      return apiResponse;
+    }
+
+    return apiResponse.AsAppCollectionType();
+  }
+
   /**
    * @method get - Makes a GET request to the specified endpoint.
    * @param {string} endpoint - The endpoint that will be used to make the request.
+   * @param {AxiosRequestConfig} config - The configuration that will be used to make the request.
    * @returns {Promise<ApiResponse<T>>} - A promise that resolves to an ApiResponse of type T.
    */
   private async get<T>(
@@ -101,4 +123,21 @@ export class OnspringClient {
     const apiResponse = ApiResponseFactory.getApiResponse<T>(response);
     return apiResponse;
   }
+
+  /**
+   *
+   * @param endpoint - The endpoint that will be used to make the request.
+   * @param data - The data that will be sent with the request.
+   * @param config - The configuration that will be used to make the request.
+   * @returns - A promise that resolves to an ApiResponse of type T.
+   */
+  private async post<T>(
+    endpoint: string,
+    data: any,
+    config: AxiosRequestConfig = {}
+  ): Promise<ApiResponse<T>> {
+    const response = await this._client.post(endpoint, data, config);
+    const apiResponse = ApiResponseFactory.getApiResponse<T>(response);
+    return apiResponse;
+  }
 }
diff --git a/src/models/PagedResponse.ts b/src/models/PagedResponse.ts
index 7ed259e..63d6573 100644
--- a/src/models/PagedResponse.ts
+++ b/src/models/PagedResponse.ts
@@ -1,10 +1,41 @@
+/**
+ * @class PagedResponse - A generic paged response model
+ */
 export class PagedResponse<T> {
+  /**
+   * @property {T[]} items - The items in the collection.
+   */
   public items: T[];
+
+  /**
+   * @property {number} pageNumber - The page number of the response.
+   */
   public pageNumber: number;
+
+  /**
+   * @property {number} pageSize - The page size of the response.
+   */
   public pageSize: number;
+
+  /**
+   * @property {number} totalPages - The total number of pages in the response.
+   */
   public totalPages: number;
+
+  /**
+   * @property {number} totalRecords - The total number of records in the response.
+   */
   public totalRecords: number;
 
+  /**
+   * @constructor - Creates a new instance of the PagedResponse class.
+   * @param {T[]} items - The items in the collection.
+   * @param {number} pageNumber - The page number of the response.
+   * @param {number} pageSize - The page size of the response.
+   * @param {number} totalPages - The total number of pages in the response.
+   * @param {number} totalRecords - The total number of records in the response.
+   * @returns {PagedResponse<T>} - A new instance of the PagedResponse class.
+   */
   constructor(
     items: T[],
     pageNumber: number,
diff --git a/tests/ApiResponse.spec.ts b/tests/ApiResponse.spec.ts
index 199952b..be92250 100644
--- a/tests/ApiResponse.spec.ts
+++ b/tests/ApiResponse.spec.ts
@@ -2,6 +2,7 @@ import { ApiResponse } from '../src/models/ApiResponse';
 import { expect } from 'chai';
 import { GetPagedAppsResponse } from '../src/models/GetPagedAppsResponse';
 import { App } from '../src/models/App';
+import { CollectionResponse } from '../src/models/CollectionResponse';
 
 describe('ApiResponse', function () {
   it('should be defined', function () {
@@ -85,7 +86,7 @@ describe('ApiResponse', function () {
     });
 
     it('should return an ApiResponse<GetPagedAppsResponse> when data contains app items', function () {
-      var mockApiResponse = {
+      const mockResponseData = {
         pageNumber: 1,
         pageSize: 2,
         totalPages: 1,
@@ -104,8 +105,8 @@ describe('ApiResponse', function () {
         ],
       };
 
-      var apiResponse = new ApiResponse<any>(200, 'OK', mockApiResponse);
-      var appsPagedResponse = apiResponse.AsGetPagedAppsResponseType();
+      const apiResponse = new ApiResponse<any>(200, 'OK', mockResponseData);
+      const appsPagedResponse = apiResponse.AsGetPagedAppsResponseType();
 
       expect(appsPagedResponse).to.be.instanceOf(ApiResponse);
       expect(appsPagedResponse.data).to.be.instanceOf(GetPagedAppsResponse);
@@ -123,7 +124,7 @@ describe('ApiResponse', function () {
     });
 
     it('should return an ApiResponse<GetPagedAppsResponse> when data contains app items', function () {
-      var mockApiResponse = {
+      const mockResponseData = {
         pageNumber: 0,
         pageSize: 0,
         totalPages: 0,
@@ -131,8 +132,8 @@ describe('ApiResponse', function () {
         items: [],
       };
 
-      var apiResponse = new ApiResponse<any>(200, 'OK', mockApiResponse);
-      var appsPagedResponse = apiResponse.AsGetPagedAppsResponseType();
+      const apiResponse = new ApiResponse<any>(200, 'OK', mockResponseData);
+      const appsPagedResponse = apiResponse.AsGetPagedAppsResponseType();
 
       expect(appsPagedResponse).to.be.instanceOf(ApiResponse);
       expect(appsPagedResponse.data).to.be.instanceOf(GetPagedAppsResponse);
@@ -158,14 +159,14 @@ describe('ApiResponse', function () {
     });
 
     it('should return an ApiResponse<App> when data contain an app', function () {
-      var mockApiResponse = {
+      const mockResponseData = {
         href: 'https://api.onspring.dev/apps/id/1',
         id: 1,
         name: 'Test App',
       };
 
-      var apiResponse = new ApiResponse<any>(200, 'OK', mockApiResponse);
-      var appResponse = apiResponse.AsAppType();
+      const apiResponse = new ApiResponse<any>(200, 'OK', mockResponseData);
+      const appResponse = apiResponse.AsAppType();
 
       expect(appResponse).to.be.instanceOf(ApiResponse);
       expect(appResponse.data).to.be.instanceOf(App);
@@ -179,4 +180,52 @@ describe('ApiResponse', function () {
       }
     });
   });
+
+  describe('AsAppCollectionType', function () {
+    it('should be defined', function () {
+      expect(ApiResponse.prototype.AsAppCollectionType).to.not.be.undefined;
+    });
+
+    it('should have no parameters', function () {
+      expect(ApiResponse.prototype.AsAppCollectionType).to.have.lengthOf(0);
+    });
+
+    it('should return an ApiResponse<CollectionResponse<App[]>> when data contains app items', function () {
+      const mockResponseData = {
+        items: [
+          {
+            href: 'https://api.onspring.dev/apps/id/1',
+            id: 1,
+            name: 'Test App 1',
+          },
+          {
+            href: 'https://api.onspring.dev/apps/id/2',
+            id: 2,
+            name: 'Test App 2',
+          },
+        ],
+      };
+
+      const apiResponse = new ApiResponse<any>(200, 'OK', mockResponseData);
+      const appCollectionResponse = apiResponse.AsAppCollectionType();
+
+      expect(appCollectionResponse).to.be.instanceOf(
+        ApiResponse<CollectionResponse<App>>
+      );
+      expect(appCollectionResponse.data).to.be.instanceOf(
+        CollectionResponse<App>
+      );
+      expect(appCollectionResponse.data).to.not.be.null;
+      if (appCollectionResponse.data != null) {
+        expect(appCollectionResponse.data.items).to.be.instanceOf(Array);
+        expect(appCollectionResponse.data.items).to.have.lengthOf(2);
+        appCollectionResponse.data.items.forEach((item) => {
+          expect(item).to.be.instanceOf(App);
+          expect(item).to.have.property('id');
+          expect(item).to.have.property('name');
+          expect(item).to.have.property('href');
+        });
+      }
+    });
+  });
 });
diff --git a/tests/OnspringClient.spec.ts b/tests/OnspringClient.spec.ts
index b489081..183d2b8 100644
--- a/tests/OnspringClient.spec.ts
+++ b/tests/OnspringClient.spec.ts
@@ -5,6 +5,7 @@ import { expect } from 'chai';
 import * as sinon from 'sinon';
 import { GetPagedAppsResponse } from '../src/models/GetPagedAppsResponse';
 import { App } from '../src/models/App';
+import { CollectionResponse } from '../src/models/CollectionResponse';
 
 describe('OnspringClient', function () {
   const baseUrl = 'https://api.onspring.dev';
@@ -454,7 +455,7 @@ describe('OnspringClient', function () {
       sinon.stub(mockAxiosClient, 'get').returns(
         Promise.resolve({
           status: 403,
-          statusText: 'Unauthorized',
+          statusText: 'Forbidden',
           data: {
             message: 'Client does not have access to read app: 1',
           },
@@ -532,5 +533,130 @@ describe('OnspringClient', function () {
     });
 
     // TODO: complete wriiting tests for getAppsByIds method
+    it('should return a promise that resolves to an api response of a collection of apps when request is successful', async function () {
+      const client = new OnspringClient(baseUrl, apiKey);
+
+      const mockAxiosClient = axios.create({
+        baseURL: baseUrl,
+        headers: {
+          'x-apikey': apiKey,
+          'x-api-version': '2',
+        },
+      });
+
+      sinon.stub(mockAxiosClient, 'post').returns(
+        Promise.resolve({
+          status: 200,
+          statusText: 'OK',
+          data: {
+            count: 2,
+            items: [
+              {
+                href: 'https://api.onspring.dev/Apps/id/1',
+                id: 1,
+                name: 'Test App 1',
+              },
+              {
+                href: 'https://api.onspring.dev/Apps/id/2',
+                id: 2,
+                name: 'Test App 2',
+              },
+            ],
+          },
+          headers: {},
+          config: {} as InternalAxiosRequestConfig,
+        } as AxiosResponse)
+      );
+
+      sinon.stub(client, '_client' as any).value(mockAxiosClient);
+
+      const result = await client.getAppsByIds([1, 2]);
+      expect(result).to.be.instanceOf(ApiResponse<CollectionResponse<App[]>>);
+      expect(result).to.have.property('statusCode', 200);
+      expect(result).to.have.property('isSuccessful', true);
+      expect(result).to.have.property('message', '');
+      expect(result).to.have.property('data');
+      if (result.data != null) {
+        expect(result.data).to.be.instanceOf(CollectionResponse);
+        expect(result.data).to.have.property('count', 2);
+        expect(result.data).to.have.property('items');
+        if (result.data.items != null) {
+          expect(result.data.items).to.be.an('array');
+          expect(result.data.items).to.have.lengthOf(2);
+          result.data.items.forEach((item) => {
+            expect(item).to.be.instanceOf(App);
+            expect(item).to.have.property('id');
+            expect(item).to.have.property('name');
+            expect(item).to.have.property('href');
+          });
+        }
+      }
+    });
+
+    it('should return a promise that resolves to an api response when request receives a 401 response', async function () {
+      const client = new OnspringClient(baseUrl, apiKey);
+
+      const mockAxiosClient = axios.create({
+        baseURL: baseUrl,
+        headers: {
+          'x-apikey': apiKey,
+          'x-api-version': '2',
+        },
+      });
+
+      sinon.stub(mockAxiosClient, 'post').returns(
+        Promise.resolve({
+          status: 401,
+          statusText: 'Unauthorized',
+          headers: {},
+          config: {} as InternalAxiosRequestConfig,
+        } as AxiosResponse)
+      );
+
+      sinon.stub(client, '_client' as any).value(mockAxiosClient);
+
+      const result = await client.getAppsByIds([1, 2]);
+      expect(result).to.be.instanceOf(ApiResponse);
+      expect(result).to.have.property('statusCode', 401);
+      expect(result).to.have.property('isSuccessful', false);
+      expect(result.message).to.be.undefined;
+      expect(result.data).to.be.null;
+    });
+
+    it('should return a promise that resolves to an api response when request receives a 403 response', async function () {
+      const client = new OnspringClient(baseUrl, apiKey);
+
+      const mockAxiosClient = axios.create({
+        baseURL: baseUrl,
+        headers: {
+          'x-apikey': apiKey,
+          'x-api-version': '2',
+        },
+      });
+
+      sinon.stub(mockAxiosClient, 'post').returns(
+        Promise.resolve({
+          status: 403,
+          statusText: 'Forbidden',
+          data: {
+            message: 'Client does not have access to read app: 1, 2',
+          },
+          headers: {},
+          config: {} as InternalAxiosRequestConfig,
+        } as AxiosResponse)
+      );
+
+      sinon.stub(client, '_client' as any).value(mockAxiosClient);
+
+      const result = await client.getAppsByIds([1, 2]);
+      expect(result).to.be.instanceOf(ApiResponse);
+      expect(result).to.have.property('statusCode', 403);
+      expect(result).to.have.property('isSuccessful', false);
+      expect(result).to.have.property(
+        'message',
+        'Client does not have access to read app: 1, 2'
+      );
+      expect(result.data).to.be.null;
+    });
   });
 });