Introduction to API Gateway

An API Gateway is a server that acts as an API front-end, receiving API requests, enforcing throttling and security policies, passing requests to the back-end service, and then passing the response back to the requester. It sits between a client and a collection of backend services.

In microservices architectures, an API Gateway provides a single point of entry for a defined group of microservices. It acts as a reverse proxy, accepting all application programming interface (API) calls, aggregating the various services required to fulfill them, and returning the appropriate result.

Key Functions

• Request Routing: Directing requests to the appropriate backend service.
• Authentication & Security: verifying user identity and managing access rights.
• Rate Limiting: Controlling the number of requests a user can make in a given timeframe to prevent abuse.
• Protocol Translation: Converting between different web protocols (e.g., HTTP to WebSocket).

Why use an API Gateway?

• Simplified Client Interface: Clients only need to know one endpoint.
• Improved Security: Hides the internal structure of the application.
• Centralized Monitoring: Provides a unified view of traffic and performance metrics.