How Do API Gateways Work?

An application programming interface (API) is basically a computer interface that allows separate devices or applications to communicate. For example, when you use a search engine, it’s an API that allows your computer to communicate with that search engine’s server to retrieve your information. Likewise, when businesses use integrated software solutions to share customer information from their CRM program with the product design team to develop new ideas, it’s APIs that enable it to do so.

An API determines the kinds of requests an application can make to another application, the kinds of data that can be transferred, and what rules to follow. APIs are crucial to software developers since they need to know what apps their programs can connect with, and they need to be kept up to date on new versions of each API to ensure the full functionality of their products. This is why API providers generally have API portals that allow developers to learn about APIs, test them out, and ask questions on discussion forums and other avenues.

These portals differ from API gateways, which are more like traffic managers. You can think of these management tools similar to the routing system a call center would use to direct calls. Basically, the API gateway controls access to your back-end systems by routing each service request to the correct microservice. Of course, it can also deny requests from unauthorized users or requests that are otherwise inappropriate. Here are some of the most common reasons organizations use API gateways and how they work.



Like most technological solutions, one of the main benefits of using API gateways is simple convenience. These gateways can aggregate requests rather than respond individually to each one, such as a largely outdated request-response architecture. This enables multiple requests to be read simultaneously and means that responses can be given for all in practically real-time. API gateways also make it possible for different clients to connect to different APIs at the same time.

These gateways also benefit companies by letting them control the flow of traffic to their services. As a result, more crucial services can be prioritized over others; for example, traffic to certain areas can be throttled if it’s causing too great a server load. This is especially important these days, considering that most companies pursue digital transformations and typically provide multiple digital services.


Gateways are also useful for client authentication. They can use various means to authenticate each message’s source and allow access to services. Each client will only need to be authenticated once for each service they have access to, making gateways a more convenient security option than most.

Client authorization is typically done at the developer portal, where each client will purchase access to APIs or otherwise become authorized for use. They’ll usually be assigned an API key at that point, which will let them past the gateway. Gateways also help providers make sure their APIs aren’t being tampered with by enabling API firewalls, message integrity checks, and other methods. They can even help with risk assessment before connected to an unknown third-party API.

Data Analysis


Data is one of the most valuable resources any organization has, and API gateways help providers make use of it to gain actionable insights and improve their business processes. For example, gateways can measure how many requests there are for specific microservices, which helps providers learn which ones to prioritize traffic and develop further. You can even keep track of how many requests an individual account makes so you can prioritize valuable clients if needed.

API gateways also translate the data each request needs into the proper format. For example, if a server typically provides HTML format answers, but the requester needs it in XML, the API gateway will automatically update it. These are just some of the best uses for API gateways. You can always find more once you start working with them.