API Testing Automation

API Testing Automation

Automated API Testing

API testing is a kind of software testing that examines APIs’ functionality, dependability, performance, and security. It is also one of the most important aspects of software testing and often requires a different skill set and testing tools than other types of software tests. API testing includes the testing of an application programming interface (API). An API is a set of functions, procedures, and classes that software or hardware provides to support requests from applications or programs. A programmer can use the API to access different parts of his application or to facilitate communication between programs in a controlled way.

Programmers can also use it to create new code that works with a specific operating system, hardware, and other programs. Applications integrated with APIs can be distributed more easily across various platforms. Programmers typically use several different API tools to manage the amount of work for a large project. API tools can work together with a programming language if the API is well defined.

Free API Testing Online Practice Test

XML API for Testing

The Cloud Storage XML API programmatically provides a RESTful interface for managing Cloud Storage data. XML supports more operations than the JSON API does. XML API for testing allows a quick and easy way to test your application by accessing all of your content in Cloud Storage easily and quickly when you are on the go or at work or want to avoid writing some complex code.

This Cloud Storage XML API is only available as part of the Google Cloud Platform Console. It’s ideal for tasks that require processing large amounts of data. It’s designed to be used in a variety of applications, including backend services to support mobile or web applications, workflow processing systems that need to process input files along with their associated metadata in an automated way, or media asset management systems where users aggregate information from multiple sources into an accessible database format.

WCF API Testing

WCF (Windows Communication Foundation) is used to develop distributed and interoperable applications. It includes a set of web services standards, tools, and a programming language that allows us to expose the underlying business logic from the Windows application. You may communicate data as asynchronous messages from one service endpoint to another using WCF. A service endpoint might be part of an IIS-hosted continuously accessible service or a service hosted in an application. The service endpoint in the application can be hosted by WCF or non-WCF. The client can be a browser or a custom code application (written in any supported programming language) which interacts with the server through the exposed service endpoints.

RestSharp API Testing Framework

RestSharp is a C# library for creating, sending, and interpreting API requests. It provides a simple interface, based on IOStreams, for sending requests and parsing responses. RestSharp is one of the most popular REST tools today because it combines several benefits and time-saving capabilities with a simple, clean interface. RestSharp was originally conceived and developed by the developers of the WCF RESTful Services Toolkit. Several existing design patterns cover many scenarios and provide a simple, consistent interface. RestSharp supports SOAP and JSON encoding standards for SOAP-based services, including XML, SOAP, and WSDL.

Karate Framework for API Testing

Karate is the only open-source framework that unifies API test automation, mocks, performance testing, and UI automation. It’s an MIT-licensed product that is easy to install and use, including translations into 32 languages. With Karate, you can make a mock server in minutes and test it in seconds. Karate provides an automated framework for testing APIs from which you can control the execution of your various tests using Python or Ruby scripts, with full UI automation support for HTTP requests on Safari and Chrome browsers. There are no limitations to what platform Karate can be used on; it also works with Amazon Web Services’ S3 bucket and Microsoft’s Azure cloud services. In addition, it has been integrated with Selenium Grid so that a single system is sufficient to simultaneously run multiple tests across different browsers on all of the world’s leading operating systems.

Cypress API Testing

Cypress is a JavaScript-based test automation framework that is free source and is often used for testing web applications that employ the latest JavaScript frameworks. It has a wide range of features and tools that help you test, such as automatic screenshots, data-driven UI tests, automated unit tests, and even code coverage. You can run it on various platforms and browsers, so there is no limit to where you can use it. It runs on both Windows and Mac desktop operating systems, as well as Linux-based servers. It also runs in the cloud via several providers such as Sauce Labs and BrowserStack. Cypress also works with all major browsers, including Chrome, Firefox, Safari, Edge, and many others.

API Contract Testing

Contract testing ensures that services can interact and that data transferred between services are compatible with a set of rules. The consequences of a poorly designed contract can lead to expensive and embarrassing mistakes for a business. To avoid these pitfalls and ensure that the code is great, developers should have certain expectations regarding API testing. What’s more, tests are not only important on the front end. Tests are also crucial on the back end of an application’s logic by ensuring no unexpected data is sent between services or queued-up functions. API testing provides confidence in your code by identifying if any issues arise in the backend before they show up client-side.

API Testing Tools

API Penetration Testing

An API penetration test is a security evaluation performed by a penetration tester to ensure that the APIs under consideration are suitably protected. A penetration test consists of a recon, social engineering, and exploit phases, each preceded by a reconnaissance phase. API penetration testing is essential for developers to ensure that their APIs are secure against malicious attacks. If your API is not properly secured, hackers could exploit it to steal personal information or gain full remote control over systems and networks. As such, penetration testing should be seen as an important security practice for all businesses with digital assets which have integrated APIs into their product or service offerings.

Swagger API Testing

Swagger is a framework for defining your API using a standard language that developers and testers can read and understand even if they have little source code expertise. The purpose of Swagger is to help you build and document your RESTful API. It allows you to develop a programming interface and generate code around it. Swagger can run in the browser or via the command line, with the results presented as HTML or JSON. It also generates code for you in many languages, including JavaScript, PHP, Ruby, Go, and Java. It can be incorporated into your existing API frameworks and tested with regular unit tests. It is also a great way for clients to understand how to access the APIs you build.

Error Codes in API Testing

Error codes in API testing are a pain to deal with. They’re not always obvious and can appear during any phase of the testing process — during testing, staging, or production. Here are the common API testing error codes:


Error Code





The API request is incorrectly constructed or invalid. As a result, the API server was unable to comprehend the request.



The If-None-Match header’s condition was not satisfied. This answer indicates that the requested document has not been changed and that a cached response should be obtained. Examine the If-None-Match HTTP request header value.


The API that the request is attempting to access is not recognized.


Resend your request to the URL given in the Location header of this response to have it processed.


The requested operation failed because the required resource could not be located.

API Integration Testing

API integration testing evaluates a collection of application programming interfaces (APIs) directly and tests to evaluate whether they fulfill functionality, reliability, performance, and security objectives. API integration testing is the last comprehensive step in testing software written with a component-based or service-based architecture. Integration tests ensure that APIs are accurate from start to finish. Endpoints in REST APIs or queries in GraphQL APIs are often evaluated end to end using this method.

Integration testing can detect practically every kind of API-related problem. It can find places where an API is not callable from the client, which could be a sign of typos or a bad URL. It can find issues related to breaking changes and unexpected function behavior. It can catch security problems, including input validation errors, XML-injection attacks, and dangerous combinations of APIs.

BDD Framework for API Testing

BDD (Behavior-driven development) testing is an agile software development approach that extends TDD or Test-Driven Development. The idea of BDD testing is that test cases are written in a natural language that non-programmers can understand. It’s an effective developer-driven testing method used for unit and functional tests, where developers write specific test cases for each feature or requirement before it is implemented. The success of BDD depends on the involvement of business people and testers. Business people should provide scenarios, and testers should specify these scenarios as executable acceptance criteria before development begins.

What are the challenges faced in API testing?

When evaluating API implementations, software testers encounter several distinct challenges. Here are the common challenges in API testing:

  1. Parameter Combination – APIs manage system communication by assigning data values to parameters and transferring those parameters via data requests. All potential parameter request combinations must be tested in the API to test for faults.
  2. Parameter Selection – API calls result in varying levels of information and functionality. The system response itself may be available in the API documentation, but the number of parameters required to make the call differs. Additional parameters may be necessary to create a more robust response.
  3. Call Sequencing – API calls may be sequenced in any order, meaning earlier API calls must complete successfully before subsequent API calls can be made. This presents additional test challenges when working with multiple APIs. Errors may occur due to timing issues, logic errors, or difficulty debugging the call sequence.

API Testing Question and Answers

  • Send the request along with the required data.
  • Obtain a response with output information.
  • Check to see if the response met the requirement and was returned as expected.

You may practice API testing and automation using the program known as the API Challenges. It was uploaded to the cloud for convenient access and is written in Java and capable of running locally. It has a working API and a number of problems for you to solve.

  • Enter Postman and find your workspace. 
  • To open a new tab, click the plus sign. 
  • Enter the request URL and method (action type GET, POST, etc.) for the API endpoint where it says, “Enter request URL,” as seen below. 
  • Press the “Send” button.

A typical API test involves sending calls to one or more API endpoints and comparing the results to what is anticipated. DevOps, QA, and development teams commonly automate API testing as part of their continuous testing procedures.

An application program interface (API) is examined during an API test to ensure that it satisfies the requirements for functionality, security, performance, and dependability. Either on the API directly or as a component of integration testing, the tests are run.

  • You must first launch JMeter and choose the Test Plan.
  • Then, add a Thread Group by performing a right-click on the Test Plan.
  • Next, you must add an HTTP request, add your API’s IP address or server name, and configure the Path and Parameters. Click on Thread Group in the context menu, choose Sampler, and then add HTTP Request. 
  • After that, look online for REST APIs that are openly accessible. For that specific API, copy the Server Name, Path, and Parameters.
  • Once you have the API, use the link to get the server name, path, and parameters. In the JMeter Test Plan’s HTTP Request, copy the values. 
  • You should now add a Listener to see the Test results. To add View Results Tree or View Results in Table, right-click on HTTP Request, select Listeners, and then add.
  • Executing your test plan is the last step. To put more pressure on your API, you can raise the number of threads. The Test Result will display the HTTP Request server’s Request and Response. The Response Data section contains the precise weather values.

Installing a REST client like Talend or vREST is one of the simplest methods to start testing REST APIs with Chrome. You can use these plugins to test the REST APIs you are developing. Once you have the preferred extension, you may begin sending and receiving queries to test the REST API.

  • Install Insomnia first
  • Check your API Docs 
  •  Use Insomnia to send your first HTTP GET request.
  • Make a POST Request
  • Make a request that needs a header
  • Make a PUT Request 
  • Make a DELETE request.

Backend testing includes database testing (including API and SQL testing).

The main benefit of using API testing is that it gives consumers access to applications without requiring them to interface with possibly dissimilar systems. This aids in the early detection and identification of faults so that they do not worsen while the GUI is being tested.

An application program interface (API) is examined during an API test to ensure that it satisfies the requirements for functionality, security, performance, and dependability. Either on the API directly or as a component of integration testing, the tests are run.

API integration testing is the process of evaluating a group of application programming interfaces, or APIs, to see if they behave as expected in terms of functionality, dependability, performance, and security.

An API (Application Programming Interface) is a type of computer interface that permits data interchange and communication between two different software systems. A software system that uses an API contains a number of operations and subroutines that can be used by other software systems.

An extensive API testing tool that Postman provides makes it simple to put up automated tests. The tests and requests you’ve made can be combined into a single automated test sequence.

An open-source automation method for testing RESTful APIs for web apps is known as REST API testing. It is frequently used to test web applications that employ JSON and XML. All methods, including GET, PUT, POST, PATCH, and DELETE are compatible. Java library REST is used.

The most popular open source, cross-platform API testing tool is SOAP UI. Testers can do automated functional, regression, compliance, and load tests on various Web APIs using SOAPUI. All of the industry-standard methods and protocols for testing APIs are supported by SOAPUI.

Similar to a password, an API token enables you to sign in to Dataverse Software APIs and take activities on their behalf. An API token is required by several Dataverse Software APIs.

When faced with a wide range of expected and unexpected queries, API testing is crucial for verifying that your API functions as intended. This procedure is intended to verify the API’s dependability, performance, and security in addition to its functionality.

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