The Role of SAST and DAST Tools in API Security

APIs—Application Programming Interfaces—help software talk to other software. They make it easier to build applications because developers can plug into existing tools rather than starting from the ground up. For example, if you need a payment system, you can connect to an API instead of building your own.

It’s fast, efficient, and flexible. But here’s the catch: APIs connect systems and share data, which means they’re vulnerable. If you don’t secure them, things can go very wrong.

What Is API Security?

Securing APIs means verifying who’s using them, controlling what they can do, keeping data safe as it travels, and making sure you can spot unusual activity. it’s about putting multiple protections in place so nothing goes unnoticed.

Why is API Security Important?

The numbers tell the story. A 2023 report from Traceable AI found that 74% of organizations had at least three API-related security incidents in the last two years. That’s not random—it’s a sign of how vulnerable APIs are right now.

What’s worse is that many companies don’t even have a clear picture of how their APIs are being used. Only 38% say they fully understand API activity, user behavior, and data flows. And traditional security tools, like Web Application Firewalls, aren’t cutting it. Over half of the respondents said those tools don’t effectively handle API-specific risks.

Keeping track of APIs is another big challenge. Nearly half of organizations struggle to maintain an inventory of their APIs. The average company relies on 127 third-party API connections, but only 33% feel confident they’re managing the risks that come with them.

What are API Security Tools and How Do They Work?

API security tools exist to protect your system. Some tools protect APIs by focusing on how they’re built. They use static analysis, which means looking at the API’s code and setup without running it—kind of like checking the blueprints of a house for cracks before construction starts. Others take a more hands-on approach, using dynamic analysis to test the API while it’s running. Think of it as someone trying all the windows and doors of your house to find where a break-in might be possible.

Smart tools go a step further. They learn what normal activity looks like for your API. If something unusual shows up—like a sudden flood of requests or a strange behavior—they catch it early. 

Types of API Security Tools

There are a lot of tools that help secure APIs, and they all work differently. Take API gateways, for instance. They control traffic and make sure requests are routed properly. They’re also responsible for checking who’s allowed in. 

Then you’ve got Web Application Firewalls, or WAFs—these are more about blocking attacks. Anything suspicious gets stopped before it reaches the API. 

For bigger-picture solutions, you can use API management platforms. These do a bit of everything: security, monitoring, organizing APIs—you name it. If you’re managing a lot of APIs at once, they can simplify things.

And when it comes to finding problems? There are different approaches. SAST tools look at the code before the API is even running. Then there’s DAST tools which tests an API while it’s live. 

Open-source tools are another option. OWASP ZAP (integrated with Codacy), for example, is great for dynamic testing. Kong Gateway handles rate limiting and authentication. Tyk focuses on being lightweight and easy to use. Grype is perfect for spotting issues in third-party libraries, while Cherrybomb helps validate API specifications and run security tests.

The Role of SAST in API Security

When you’re developing an API, one of the biggest concerns is security. That’s where SAST—Static Application Security Testing—comes in. These tools are all about finding vulnerabilities in your code before the API ever sees the light of day. Instead of running the code, SAST tools analyze it as it is, like checking over a plan before starting construction.

The great thing about SAST tools is how easily they can slot into your workflow. If you’re using an IDE or a CI pipeline, these tools integrate directly, pointing out issues while you’re still coding. This makes them perfect for catching problems early—way before deployment.

This approach makes SAST tools ideal for every development phase, from the initial stages to release, which aligns with shift-left security testing principles.

Typically, SAST tools may find input validation issues or insecure data handling. SAST tools help you stick to frameworks like GDPR or HIPAA and take care of compliance for you.

But the real payoff is catching these issues when they’re cheap and easy to fix. A problem found early on is way less painful than one discovered after deployment. It’s just a smarter way to work, making your API stronger from the start and saving everyone a lot of headaches down the line.

The Role of DAST in API Security

When it comes to DAST—Dynamic Application Security Testing—it’s all about testing APIs while they’re live. These tools don’t just look at the code. They go further by interacting with the API in real time, throwing real-world scenarios at it to see how it handles them. Think of it as stress-testing your system to uncover vulnerabilities that might not be obvious otherwise.

One of the things DAST tools are good at is simulating attacks. They mimic the kinds of threats your API might face if someone with bad intentions came knocking. This could be anything from injecting harmful code to pushing your system to its limits with unexpected inputs or high traffic. The goal is to find the cracks before someone else does.

APIs usually have multiple endpoints, and each one is a potential weak spot. DAST focuses on those endpoints, checking for problems like misconfigurations, cross-site scripting, orinjection attacks. These are the types of vulnerabilities that hackers love to exploit, so catching them early can save you a lot of trouble.

Another thing that sets DAST apart is how it can spot unusual behavior in the API’s responses. For instance, if the API starts leaking data it shouldn’t or slows down in ways that don’t make sense, that’s a sign something might be off. Static testing tools usually don’t catch things like this, but DAST tools are built for it.

Integrate SAST and DAST for Comprehensive API Security

You can’t just rely on one tool to secure your APIs. If you use only one method, you can expose your API to security gaps. That’s where combining SAST and DAST comes in.

SAST is about catching issues before anything goes live. It looks at the code—whether it’s the source, bytecode, or binaries—before it’s running. You catch the vulnerabilities early on—things like insecure input validation, or maybe weak encryption. 

But once the API is live? That’s where DAST comes in. You can’t see everything in the code when the API’s running so DAST tests the API in action, simulating what real attackers would do. If the API handles weird input poorly or can’t manage too many requests, DAST shows you that. Static tests don’t catch this. It’s about how the API actually behaves under stress or unpredictable conditions.

The combination of both—SAST and DAST—really ties everything together. SAST handles security during development. And DAST, once the API’s out there, making sure everything works under real conditions. 

APIs change all the time. You make updates, things shift. And every change opens the door for new vulnerabilities. That’s why you need both. Testing constantly throughout the lifecycle is key to making sure you’re protected, whether you’re writing the code or it’s out there on the internet.

Codacy’s security tools make this easy. You catch bugs early with SAST while you’re writing code, then run DAST to test things once the API’s live. It’s an efficient way to make sure your API is solid, without jumping through too many hoops.

If you want a better, simpler way to secure your API, give Codacy a shot. Start a free trial and see for yourself how our tools cover everything from start to finish.