What is the function of an API gateway?

The function of an API gateway is primarily to provide a single access point for multiple microservices. This architecture is particularly relevant in environments where services are broken down into smaller, independently deployable components, commonly referred to as microservices.

An API gateway acts as a mediator that routes incoming requests from clients to the appropriate microservice, handling various tasks such as authentication, request routing, and response aggregation. This centralization simplifies client interactions because clients only need to know about the API gateway instead of the details of each individual service. This design enhances security by allowing easier implementation of security measures in one place, facilitates monitoring and logging of requests, and can optimize the performance of the system by managing load balancing and caching responses.

The other options cover different aspects, such as server health monitoring, direct client-server communication, and resource management, but they do not encompass the core function of the API gateway as primarily serving as a unified entry point for microservices.