What is an API gateway?

An API gateway acts as a reverse proxy to accept all application programming interface (API) calls.

Learning Objectives

After reading this article you will be able to:

  • Define API gateway
  • Explain why API gateways are important
  • List the different types of API gateways

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What is an API gateway?

An API gateway is a service, device or proxy that acts as an intermediary that accepts, transforms, routes, and manages API traffic to backend services. It allows for the seamless communication and transfer of data between endpoints, and can be useful when there are multiple platforms that need to interact with each other without granting direct access to the other’s APIs. For example, an API gateway could be used in a company’s IT department to allow different departments to share data without requiring them to access each other's internal systems.

API gateways can handle tasks such as authentication, rate limiting, caching, and request/response transformation, reducing the burden on the application and improving the overall security and performance of the system.

What is an API?

An API stands for application programming interface, and it is a set of protocols, standards, and tools that allows for the seamless exchange of information to access and integrate data, applications, and services from different platforms and systems.

How does an API gateway work?

There are several steps an API gateway must take to communicate between two endpoints. First, an external consumer sends a request to the API service, typically through an HTTP or HTTPS connection. The API gateway receives the request and routes it to the appropriate microservice based on the URL and other criteria. Next, the gateway verifies the source of the request via mTLS, JWT, or the API key, checks the request against the source's authorization, and makes sure the external consumer is not sending too many requests at the same time.

Once the source of the request is verified, the API gateway transforms the request and response payloads as needed to meet the requirements of the external consumer or the underlying microservices. When the gateway receives a response from the microservice, it performs any necessary transformations, and returns the answer to the external consumer. Lastly, the gateway collects data on the requests and responses, allowing organizations to monitor the performance and usage of the micro services and identify any issues or trends.

What are the benefits of using an API gateway?

An API gateway is an important tool for building out and managing APIs for several reasons:

  1. Abstraction: API gateways provide a unified entry point for external consumers to access a set of microservices, abstracting the underlying implementation details and allowing the microservices to evolve independently.
  2. Security: API gateways can handle security tasks such as authentication, authorization, and rate limiting, improving the security of the underlying microservices.
  3. Performance: the API gateways cache responses and perform request/response transformation, improving the system’s overall performance.
  4. Developer experience: API gateways provide analytics, documentation, and testing tools, making it easier for developers to build and maintain microservice-based applications.
  5. Consumer experience: API gateways make it easier for consumers to discover and use the APIs provided by the microservices, improving the overall ease of use and user experience.

What is Cloudflare API Gateway?

The Cloudflare API Gateway offers several advantages to organizations looking to build and deploy APIs. With its global network and caching capabilities, Cloudflare can significantly improve the performance and speed of API requests and responses, reducing latency and improving the overall user experience. The gateway also includes API discovery, integrated API management, and layered defenses.