Automating API Tests for a C# Rest API: Tools and Approaches

Automating API Tests for a C# Rest API: Tools and Approaches

3 July 2024 Stephan Petzl Leave a comment QA

When it comes to automating tests for a Rest API written in C#, there are generally two main approaches you can consider:

  • Using a GUI tool (e.g., SoapUI)
  • Employing a programmatic approach with a test framework

Each of these methods has its own set of pros and cons. Let’s delve into the details to help you make an informed decision.

GUI Tools

GUI tools like SoapUI and Postman are popular for their ease of use and rich features. However, they may not suit every scenario.


  • Intuitive interface, which makes it easy to set up and run tests.
  • Minimal setup time compared to programmatic approaches.
  • Useful for quick prototyping and exploratory testing.


  • May not integrate well with version control systems like Git.
  • Limited customization options for complex testing scenarios.
  • Paid versions can be costly, and extending free versions may require additional skills (e.g., Groovy for SoapUI).

Programmatic Approach

Writing your own test framework offers greater flexibility and integration capabilities but comes with its own challenges.


  • Highly customizable and adaptable to specific needs.
  • Easy to integrate with version control systems like TFS or Git.
  • Seamless integration into build pipelines, allowing tests to run automatically after each deploy.
  • More control over the technical implementation of the tests.


  • Requires more time and effort to set up initially.
  • May require additional coding skills and maintenance effort.

Real-World Examples

In one scenario, a team decided to build their own C# API testing framework using RestSharp or HttpClient. They chose this approach due to the following reasons:

  • Ease of data setup using the same Entity Framework models as the API.
  • Better version control for both code and test data.
  • Integration into their build pipeline to run tests automatically after each deploy.
  • More control over the technical aspects of the tests.

Another team opted for a lightweight framework in NodeJS, keeping data in JSON files. They chose this over SoapUI due to the high cost of the paid version and the complexity of extending the free version.

Postman was another tool used by a team focused on minimizing setup time and concentrating on test cases rather than building a test framework. This was particularly effective for their typical API and test scenarios.


The choice between a GUI tool and a programmatic approach depends on your specific requirements, team expertise, and project constraints. While GUI tools offer ease of use and quick setup, programmatic approaches provide greater flexibility and integration capabilities.

Enhancing Your Testing Strategy

If you’re looking for a no-code solution to streamline your testing process, consider using Repeato. Repeato is a no-code test automation tool for iOS and Android that leverages computer vision and AI to create, run, and maintain automated tests. Its simplicity and speed make it an excellent choice for quality assurance teams, allowing them to focus on test scenarios rather than the complexities of test setup.

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