API Gateways

What is an API gateway?

An API gateway is an infrastructure component that is a single-entry point that sits in front of one or more backend APIs. Sitting between the client and the services, the Gateway can provide vital cross-cutting functionality and reduce complexity for the individual services.

The Gateway handles each client's request, inspects the request, and routes it to the proper API, allowing the client to be ignorant of the backend implementation.

What API gateway is not?

An API gateway is not part of an application; it should not contain any business logic or provide mashup services beyond the unified URI it gives to the client to obfuscate the backend architecture.

What can an API gateway offer?

While there is almost no limit to what an API gateway can offer, some of the more mainstream usages are.

• Security offloading.

• SSL offloading.

• Load balancing.

• API versioning.

• Client-specific routing.

• Monitoring

• Caching

Do you need an API gateway?

An APIs existence implicitly defines an application as non-trivial; consequently, the arguments against having a gateway are slim. The availability of open-source and free API gateway solutions makes the barrier to entry extremely low, with the most basic configurations being invisible to a solution.