Here's how you can level up your API testing skills as a software tester.

Understand the basics of API. Start learning API testing with dummy APIs. Learn tool which is used to execute the APIs for example postman. Learn about GET,POST,PATCH,UPDATE AND DELETE apis. Http status codes.

To get started with API testing, it's crucial to first understand the basics of JSON and XML, the two primary data formats used in APIs. JSON, with its key-value pairs and arrays, is easy to read and write, while XML uses tags and attributes to structure data. Once you're familiar with these formats, choose a user-friendly tool like Postman, which offers an intuitive interface for interacting with APIs. Focus on learning key HTTP response codes, such as 200 OK (success) and 404 Not Found (resource missing), as these will help you evaluate the outcomes of your API requests. By mastering these fundamentals, you'll lay a solid foundation for effective API testing.

1st of all you should know what is API and what it does. Understand what are the methods like Put, Post, Get etc and what they do. For example, if you want to understand how any payment method works, try to search for API's related to payment methods and they are easily available on net. Get some understanding of different types of API's like Rest, SOAP. Then just try to get some knowledge of easy tools like Postman to test them. If you use this tool for a week or so, you will get good hand's on API Testing. Its easy and fun to know API's because thats where whole process actually happen. Later once you are comfortable with API testing, you can expand your area with performance, stress, load and other important types of testing.

To deepen your understanding of APIs, start with the basics by learning what APIs are, their types, and their purpose. Understand the HTTP protocol, including methods (GET, POST,PUT,DELETE etc.), status codes, headers, and cookies. Learn RESTful principles like statelessness, resource-based URIs, and common data formats (JSON, XML). Familiarize yourself with authentication and authorization mechanisms, including API keys and OAuth 2.0 . Lastly, study API documentation tools like Swagger/OpenAPI and Postman, and practice reading and understanding API docs from popular sources

To get started with API testing, it is necessary to understand why APIs exist and the problems they solve. Then, you need to learn about the different types of APIs. After that, you should find an example and explore how it works. Without good examples, it is really difficult to get the logic behind APIs. Also Postman is a really useful tool.

Its important to learn the right tools to contribute effectively in API testing. there are many tools available for API testing and in my experience i have worked with Postman, SoapUI and JMeter. Postman - Leverage Postman to manually test the APIs, Create Collection of APIs, write test suites, write tests and automate them. SoapUI - SoapUI is leveraged for REST and SOAP API's different Environments can be configured, DB plugins are supported, Perf testing is possible, Customized Automation framework development is supported, and there are many more functionalities are supported which can be leveraged for API manual and automation Testing. JMeter - Useful for performance and Load testing.

An API (Application Programming Interface), is like a translator or a kind of a bridge that helps different software programs talk to each other. For example, when we use an app to check the weather forecast for next day, the app uses an API to get the latest weather information from a weather service and presents it on our screen. It does work based on a process of: 1. request (to the API for information) 2. processing (API gathers the requested data) 3. response (API sends back an info in a structured way, usually in JSON or XML file)

An API (Application Programming Interface) is a set of rules and protocols for building and interacting with software applications. It defines methods and data formats for communication between different software systems. APIs allow applications to share data and invoke services without understanding their internal workings. Key aspects include endpoints (specific paths for requests), methods (GET, POST, PUT, DELETE), requests and responses (formats like JSON or XML), and authentication and authorization for secure access. APIs are crucial for integration and interconnectivity in modern software ecosystems.

Curiosity?? and mastering the right tools for the right problem are crucial and these tools are helpful: 1. Postman: Ideal for testing REST APIs. It lets you send requests, organize collections, write tests, and automate workflows. 2. SoapUI: Perfect for both SOAP and REST APIs. It provides advanced testing capabilities, including functional, security. 3. Insomnia: A simple, intuitive tool for quick API testing. It supports REST and GraphQL, and its streamlined interface is great for rapid development and debugging. 4. Swagger: Excellent for API documentation and testing. It allows you to visualize and interact with API endpoints through a web interface. 5. JMeter: Primarily for load testing APIs, ensuring they can handle expected traffic.

API Automation benefits with several factors, It can significantly improve your testing quality, efficiency, and consistency. API often undergo changes and updates and having Automated scripts ensures that new changes does not break existing functionality. API Automation helps maintain broad coverage of tests scenarios, including edge cases and boundary conditions which might be overlooked in manual testing. Automation tests runs much faster than manual tests which improves efficiency. Automation enables reduced risk of human errors and it allows tests to be integrated early in the SDLC, which promotes identifying defects in early stages.

Automating your API tests is important for efficiency. Use tools like Newman (Postman's command-line tool) or frameworks like REST Assured for scripting tests and integrating them into your CI/CD pipeline. For example, you can automate your tests to run with each code push, for continuous validation of your API's functionality. This allowing you to catch issues early in the development cycle. By focusing on these three areas—understanding APIs, mastering tools, and learning automation—you can enhance your API testing capabilities and contribute more.

API Automation is easier and less time taking of you have the framework already in place. You can add extensive test cases in automation suite. If test plan is thoroughly created considering edge cases it helps to cover all scenarios. In respect of time, we have also tried API automation straightway skipping manual testing and has helped to some extent. Usually 60-80% testcases are straightforward which can be automated easily, remaining might need more efforts to test and automate if there are too many dependencies on other API's responses or maybe some new thing is added to the application.

Automated API testing enriches the software quality and accelerates release cycles. Several other benefits of automating API tests includes early bug detection, time efficiency, improved collaboration, and Continuous Integration and Continuous Delivery (CI/CD) Support.

Postman & rest Assured playing big picture, Learning automation involves acquiring skills and knowledge to use tools and techniques that automate repetitive tasks and processes. This can include writing scripts, using software frameworks, and employing technologies like robotic process automation (RPA) and artificial intelligence (AI). Key areas include: 1. Programming and Scripting: Writing code in languages such as Python, JavaScript, or Bash to automate tasks. 2. Automation Tools: Using software like Selenium for web testing, Jenkins for CI/CD, or Ansible for IT automation. 3.Robotic Process Automation (RPA): Implementing tools like UiPath or Blue Prism to automate business processes

API testing is all about driving through a combination of various requests .. it's easy to test 100s of combinations through api than UI as the time taken to exercise apis are much lesser. Designing scenarios is critical,be it authentication of your services or validation of request fields and error conditions, test coverage gives your code coverage a big fillip than most other UI tests

One thing I have noted is the fact that, test cases ensure that edge cases are carefully looked at and fully scrutinised. This ensures that the API functionality in the production environment will not invite concerns due to failures in certain API call scenarios. Test cases are a safe guard to ensure that all the anticipated scenarios occur just as they were envisioned. The mantra in a big way when creating test cases, should be, what can go wrong, will go wrong.

There are 2 components to consider on this matter. First of course is test case design while another critical one is the test data preparation. Basing on my experience in testing APIs between our org, the vendor who owned API and an external client, its is key to define the exact scope of API functionality, then the exact scope of the functional and non-functional testing. Usually we were failing at the early stage due to lack of proper API setup (API ends points), lack of proper user entitlements and lack of relevant data (especially in transaction testing, the calendar dates are crucial). In general, the functional test case design does not differ much from ordinary UAT test case design.

Designing comprehensive test cases for API testing is essential for ensuring robustness. My approach involves covering success paths, failure paths, and edge cases, focusing on request and response structures, HTTP methods, and error codes. I anticipate real-world use cases to validate the API's functionality under various scenarios. Additionally, I include performance benchmarks to assess load handling and response times, ensuring the API meets all user expectations.

Designing test cases for an API ensures its functionality, reliability, and security by creating a comprehensive set of test cases for all scenarios, including normal operations, edge cases, and error conditions. First, thoroughly review the API documentation to understand endpoints, request methods, response formats, authentication mechanisms, and business rules. Define test scenarios for positive cases, negative cases, boundary conditions, performance checks, and security validations. Prepare comprehensive test data for each endpoint. Write detailed test cases including test case ID, description, preconditions, request method and endpoint, request headers, request body, like wise

One of the ideas I have found helpful in security testing is employing the ' Zero trust' mindset. Every payload detail should be keenly checked to ensure that it won't be manipulated to inject unwanted data. JWT tokens, usernames, passwords etc should be well validated. In terms of session tokens, their validity periods should be tested as failing when they should with the right error responses returned and they should lead to successful API calls when they should. In summary, the security scenarios should be covered fully, where necessary, the developer should be able to remedy coded points that require further review and action.

The security analysis will be of added help in strengthening the capability of API testing and help to take necessary steps to identify and mitigate risks, ensuring the development of a robust and safe application. Knowledge of the most common vulnerabilities and security testing techniques, such as penetration testing and fuzz testing, enables the decloaking of hidden bugs and security flaws. It further elevates the testing process by ensuring proper authentication and validation of the data, coupled with encryption in the APIs, using security tools. Collaboration with the security teams and staying updated with all the latest security trends would build one's skills better and make them a valuable resource for the team.

Manual and automated penetration testing uncover complex vulnerabilities, and tools like Burp Suite, OWASP ZAP, and Postman provide detailed security analysis. Automated security scans will also help to QA to identify common code vulnerabilities . Authentication and authorization testing are also part of security testing to ensure proper access controls, while input validation prevents injection attacks. To avoid sudden change in pattern one should logging and monitoring detect suspicious activities, and regular updates of third-party dependencies patch.

Security testing is a crucial part of API testing. I focus on identifying common security threats like injections, authentication issues, and data exposure. Performing regular penetration testing and using security-focused tools helps me uncover vulnerabilities. This proactive approach ensures the application is safeguarded against potential attacks and data breaches, which is vital in today's digital landscape.

Analyzing security involves assessing the measures in place to protect information systems from unauthorized access, use, disclosure, disruption, modification, or destruction. include: 1. Identify Assets:Determine what data and systems need protection. 2. Threat Modeling:Identify potential threats and vulnerabilities. 3. Risk Assessment: Evaluate the likelihood and impact of various threats. 4. Security Controls: Examine existing security measures and determine their effectiveness. 5. Penetration Testing: Simulate attacks to find weaknesses. 6. Compliance Checks: Ensure adherence to relevant laws, regulations, and standards. 7. Monitoring and Logging: Continuously track and analyze security events. 8. Review and Update

I've observed that API testing is constantly evolving, with new tools and methodologies emerging regularly. To stay ahead, I continuously practice by working on real projects, experimenting with various types of APIs, and tackling complex testing scenarios. I've engaged with the testing community, shared knowledge, and learned from others' experiences. I believe proficiency comes with practice, and my hands-on experience has been crucial in becoming skilled in API testing.

To enhance your API testing skills, you need to constantly practice and stay updated. Experiment with different types of APIs, work on real-world projects, and challenge yourself with complex test scenarios. Engage with the testing community, share your knowledge, and learn from others' experiences. Remember, proficiency comes with practice, and the more hands-on experience you gain, the more skilled you'll become in API testing.

The concept of practice cannot be overstated enough. If you want to level up then you have to practice and experiment. Elite athletes train for hours EVERY DAY, if you want to be an elite API tester then you need to practice and push yourself to new limits. Everyday learn or do something, knowledge not used once gained is knowledge lost. Put your knowledge to work every day, if things are boring or repetitive, then find a new way to do it. Use a different tools, change your approach. optimize. find a method that works for you and do, again, and again, and again. There is no substitute for experience.

A lesson learned story: we conducted extensive API testing for a new online banking feature with our client, where they were a part of it. Unfortunately, we failed to log the proof of testing & its final positive results. When a formal signoff was supposed to be given by client's senior manager , there was no documentation to refer back to since client thought we will cover it while we assumed client is going to capture it. As a result, we had to repeat the entire testing process from scratch, leading to significant delays and increased costs. This incident underscored the importance of meticulous documentation in API testing to ensure accountability and efficiency. Since that case it was always agreed in advance who owns logs and evidence.

To level up API testing skills, keep on learning good practices and keep updated with industry trends. Learn API testing tools REST, SOAP UI etc. API documentation is important to be practiced. Work with different types of authentication mechanisms OAuth, JWT tokens, API keys etc. API automation plays a key role like Postman, Rest Assured and libraries Python, RestSharp