Improve Security and Reliability: the Power of Automated API Testing

Published: February 19, 2025

Picture this: You’re in the middle of a big product launch. Everything is going smoothly until…the payment gateway crashes right when your first customer tries to make a purchase. Frantic emails start flying, customer service is overwhelmed, and you’re left wondering how this could have happened. It wasn’t an issue with your app, but with the third-party API you integrated with to handle transactions. While it’s frustrating, it’s also a bit terrifying. Such failures aren’t just inconvenient, they can expose your systems to security risks, reputational damage, and lost revenue.

This scenario may sound familiar to many of us and it highlights the importance of keeping APIs both reliable and secure. That’s where automated API testing comes in. Let’s explore why it’s a game-changer for businesses relying on API-driven integrations.

What is Automated API Testing?

Before you panic and imagine complex testing scripts that only seasoned developers can understand, let’s break it down: Automated API testing is simply the use of tools and scripts to automatically test your APIs to ensure they are working as expected. These tests can cover reliability (Is your API up and running?), security (Are there any vulnerabilities?), and performance (Is it fast enough under load?).

It’s like having a tester who never sleeps, ensuring that the APIs your applications depend on are running flawlessly around the clock. Instead of manually checking APIs or crossing your fingers that they won’t fail, automated testing provides you with peace of mind, knowing that any potential issues are caught early before they can cause harm. Think of these API tests as a ‘handshake’ that validates the API contract you’re consuming or providing. Your tests can validate the key aspects of the contract to ensure the “input and output” behaviour hasn’t changed.

At Solsys, we’ve worked closely with product teams and security experts to build some amazing demonstrations of automated API testing. We’ve seen firsthand how this approach can immediately detect issues, streamline development, and improve security.

Key Considerations for Effective Testing

So, how do we ensure that these tests are adding value? Here are a few key points to keep in mind:

1. Human-Centric Language: You want tests that make sense to everyone—not just the developers, but also the business teams. Writing tests in plain, understandable language helps bridge the gap between technical and non-technical stakeholders, ensuring that everyone is on the same page when it comes to the API’s health and specifically what’s being tested and validated.
2. Visibility and Reporting: When a test fails, you don’t want to spend hours playing detective. Clear, actionable reports make all the difference. At Solsyslabs, we’ve seen that readable test outputs and easy-to-navigate dashboards make troubleshooting a breeze, helping teams quickly identify and fix issues.
3. Test Failure Transparency: Knowing why a test failed is just as important as knowing that it failed. Transparent failure logs make it easy to pinpoint the root cause of issues. This minimizes the guesswork and ultimately accelerates resolution.
4. Test Code Maintenance: APIs evolve and so should your tests. It’s crucial to ensure that your tests evolve alongside your API. This is a core part of maintaining an effective testing framework. Test code that keeps up with new versions of the API means less risk of outdated tests missing critical changes. This means that test code should be written to be readable and maintainable, like your main application.
5. Ownership of Tests: Tests must be written and evolve immediately as the API that they’re testing changes. If your product team owns an API, the team that builds or deploys that API should iterate on its tests. We can’t forget that tests belong to everyone involved in the API’s lifecycle, not just the developers. Involving everyone on the product team in test coverage and test purpose ensures that the tests remain relevant, up-to-date, and effective.

How Automated Testing Enhances Security and Reliability

Automated testing is not just about catching bugs. It’s about making sure that your valuable priorities (like security and reliability) are continually checked.

Security-related failures can have far-reaching consequences. Imagine if your API had an authentication vulnerability or a misconfiguration that exposed sensitive data to unauthorized users. That’s a disaster waiting to happen. By including security tests as part of your routine testing suite, you’re actively preventing these issues from slipping through the cracks. This means that “negative” tests should be part of the validations. For example, if I provide no credentials, do I get the correct failure message? Testing that error conditions are validated and responding correctly (especially security error conditions) avoids unexpected behaviour when things go wrong, and ensures your team can make sense of errors.

Testing through an API gateway is another important consideration. It ensures that security policies and controls are consistently applied across all services, preventing weaknesses in one part of your system from affecting others. By regularly testing for vulnerabilities and misconfigurations, you’re making sure your systems stay secure, not just functional.

The Benefits of Automated API Testing

Here are some key benefits that automated API testing provides:

• Improve Reliability: Catch issues early to ensure your API behaves as expected in all environments.
• Detect Security Risks: Identify vulnerabilities before they become serious problems.
• Save Time and Effort: Automate routine tests so your developers can focus on building new features rather than fixing broken APIs.
• Foster Collaboration: With clear reporting, everyone (developers, testers, security teams, and product owners) can work together more effectively to address issues.
• Reduce Costs: There’s nothing more expensive than having several teams all chasing an issue together to find out where something is failing when things go wrong. Failing fast through tests early in the development cycle is the cheapest way to find and fix problems.

Other Use Cases for Automated API Testing

Automated testing isn’t just useful during the initial API development phase. It’s also invaluable in other scenarios such as:

• Continuous Integration: Ensure that every change made to the API doesn’t break anything by testing automatically whenever new code is pushed.
• Production Environments: Regularly test APIs in production to ensure they remain reliable and secure, even after deployments. Designing tests for this type of reuse is a skill in itself, but well worth the effort.
• Onboarding New Third-Party APIs: Testing new third-party APIs quickly ensures they meet your security and reliability standards before integration.
• Regression, Performance, and Load Testing: In DevOps workflows, automated testing can be used for regression testing (ensuring nothing else broke), performance testing (ensuring the API can handle traffic), and load testing (checking how the API performs under stress).

API Testing Has a High ROI

Automated API testing is an absolute must for businesses relying on API-driven integrations. By building solid, automated testing frameworks and making them a core part of your development lifecycle, you’ll not only ensure that your APIs are reliable and secure, but you’ll also save time, reduce headaches, and prevent costly errors.

So, while testing might seem tedious, think of it as an investment in your future success. With automated API testing, you can rest easy knowing that the only surprises in store will be the good kind! Happy testing!

Marek Suchomski is a Technical Account Manager at Solsys, where he has been dedicated to working with clients and our R&D Solsyslabs team on API security and reliability. With a strong development background, Marek brings a deep understanding of both the technical and business aspects of the industry. As both a manager and a long time developer, Marek is committed to assisting his colleagues in navigating the evolving landscape of APIs and cybersecurity.