API Gateway hierarchy

API gateways serve as a single point of entry through which external users can connect to a collection of microservices. This conceals the intricate operational complexity and empowers microservices to develop autonomously.

API gateways take charge of security functions including authentication, authorisation and rate regulation. This fortifies the security of the underlying microservices.

Product, API and endpoint relationships

• Products: Each product contains at least one API.

• APIs: Each API can be part of multiple products.

• Endpoints: Endpoints are API-specific and cannot be in multiple APIs.

Products

A Product is a collection of APIs that has been grouped together to make them easier to consume, based on the functions they perform. Each product contains at least one API.

You need to subscribe to a product to get access to its APIs. Once subscribed you will be issued with a subscription key. This key is sent as a header when using the APIs contained in the product.

APIs

An API (application programming interface) is a set of subroutine definitions, protocols and tools for building application software. Each API contains at least one endpoint. APIs can be included in multiple products.

To use an API you must be subscribed to a product that it is present within.

Endpoints

An endpoint is a function that can be performed by an API. An endpoint exists in only one API. Each endpoint has a description of what it does. All the required information to use the endpoint can be found on the APIM.