June 17, 2021

What Is an API Key?

Your business virtually runs on Application Programming Interfaces (APIs). They enable internal applications, customer-facing applications, and application integrations with your business partners to talk with each other and exchange data and information. All these connections streamline the purchase of products and services for customers, and they drive greater efficiencies across your internal workflows.

By leveraging APIs, your business can add value to those workflows by integrating enterprise systems and connecting to advanced technologies. These include the Internet of Things (IoT) networks, robotic systems, machine learning, and social media Big Data sets.

One of the options for securing an API is the API key. It’s a long string of randomly-generated characters and may look something like this:


The key consists of code passed between an API and application services. The code calls programs from another application, and the key then identifies the end-user, the developer of the code, and the application making the API call.

In this sense, the API key acts as an authentication token or a unique identifier. It guarantees authorization by checking the API’s associated access rights to see whether the application making the call has approved access.

How Are API Keys Used?

API keys are handled by endpoints and used with applications and website interfaces usually referred to as projects by software developers. The keys are not as secure as authentication tokens, but they do provide a layer of security in that they can identify the project behind a call.

Developers can code API keys to restrict project usage to specified environments or a range of IP addresses. This way, an extensible service proxy can reject calls without authorized access from a particular API.

How Do API Keys Authenticate Users?

API key strings check whether an API in an application is enabled, and it tracks and controls how the interface is utilized. This prevents abuse of the API by malicious bots and other forms of cyberattacks.

For example, the keys verify end-user authorization by determining if calls have received permission to access a specific application service. This is an important function because end-users may have authorized access to some but not all of the individual services within an application.

The key can also authenticate users, verifying that the person making the call is actually the person they claim to be and not a hacker spoofing the end-user. The endpoint can also be authenticated by the key, checking with the device authentication token. This confirms if proper permission has been granted.

This comes in handy for services that end-users are allowed to access on one of their devices—such as an on-premises desktop—but not on a mobile device connected to a public Wi-Fi network (unless using SSL, TLS or HTTPS). The API server has the final say regarding whether to authorize each request, as defined by the authentication token.

Making sure you code API keys to properly authenticate is critical. CISO Magazine reported earlier this year that Starbucks left an API key online without password protection that could have been used by attackers to access internal systems and manipulate the list of authorized users. Additionally, ZDNet recently reported that cyber-security firm Imperva accidentally exposed an internal server last year, and this allowed a hacker to steal an AWS API key.

How Do You Get an API Key?

When software developers want to program an API to connect one of their application services to another application service, they need to request an API key from the owner of the application service they want to connect with. Application owners who make connections to their application services available to external developers will typically publish the process for getting an API key.

In most cases, the requesting developer must have at least one API key associated with their application project. Getting the key is quick and easy and mainly involves setting up an account with the application owner and then registering the project for which the key is needed. From there, it’s just a matter of interacting with a console the application owner has created and using drop-down menus to create the credentials to generate the new API key.

The keys rarely expire, but you should double-check just in case the application owner has established a requirement to renew your access to the key, which might be on an annual basis or perhaps every other year.

You should add application and HTTP restrictions to the key before using it in production. Application restrictions are based on the application type and specify which websites, IP addresses, or apps can use the API key. An HTTP restriction could be applied to allow a specific URL with an exact path, such as https://www.example.com/path.

As you code API keys for your applications, be sure to give them the same level of protection as usernames and passwords. The keys should not be hard-coded into source code repositories. This is particularly important for mobile app development since mobile apps are easily downloaded from publishing stores. The code can be directly deobfuscated or reverse-engineered if developers don’t use protective measures against potential cyber threats.

The Value of API Keys to Your Business

API keys play a key role in making sure the connections between application services are valid and authorized. This includes authenticating both the end-user and the device using an application to make a call to another application for a specific service.

Getting the coding right is critical for your business. API keys help you make sure customers can access the services and data they need to place orders without gaining access to any information they are not privileged to see. The same holds true for your internal users. Within each of your corporate applications and databases, there are some areas users can see and others that they can’t. API keys help make sure they only see what they are supposed to see.

APIs are a vital component of the products we build at 3Pillar Global. Whether you are struggling with your current APIs, or planning an API strategy, be sure to download the Business Leader's Guide to APIs. To learn how we can help your product development efforts, contact an expert today.


A Business Leader’s Guide to APIs