GraphQL API Gateway Overview
What is a GraphQL API Gateway?

What is a GraphQL API Gateway?

A GraphQL API Gateway is an API Gateway specifically designed to work with GraphQL. Traditional API Gateways are designed to work with REST APIs, where the URL and HTTP method are usually enough to route the request to the right service.

GraphQL APIs are different in that they usually use a single endpoint, and the content of the request body is what determines which service or services should handle the request.

GraphQL API Gateways don't usually have a single origin. The nature of the language makes it an excellent solution to aggregate and compose multiple services into a single unified API. Therefore, GraphQL API Gateways also have the responsibility of aggregating and composing data from multiple services. Widely known patterns for this are the Schema Stitching Pattern and the Federation Pattern.

As with traditional API Gateways, GraphQL API Gateways are responsible for:

  • Authentication
  • Authorization
  • Rate limiting
  • Logging
  • Monitoring
  • Caching
  • Tracing
  • Error handling

Depending on the complexity of your architecture, it might be beneficial to have a single GraphQL API Gateway that handles the above listed responsibilities for multiple services. E.g. if you're composing multiple backends into a unified API, handling authentication, rate limiting, logging, monitoring, tracing and error handling at the gateway level allows you to simplify your services. Applying the API Gateway pattern will not just reduce complexity and repetition in your services, but also ensures that you establish a layer of security between your services and the outside world.

The GraphQL API Gateway can take ownership of a wide range of security responsibilities. It can validate the incoming request, ensure that the agent is authenticated and authorized to perform the requested operation, and that the request is not malicious.

The Gateway can calculate the complexity of a request and apply rate limits and quotas. In addition, it can also apply the Persisted Operations Pattern to only allow pre-registered Operations for extra security.

As you can see, the GraphQL API Gateway is a powerful pattern to help you build secure and scalable API architectures. At the same time, it's a complex pattern that requires a lot of work to implement and maintain. For that reason, I'm creating this website to help you understand the different ways of using and implementing GraphQL API Gateways.