# API Gateway
Confidence: high
Last verified: 2026-05-22
Generation: human_only


## TL;DR

An API Gateway is a single entry point for all client requests to a microservices architecture. It handles cross-cutting concerns: authentication, rate limiting, request routing, protocol translation, caching, logging, and API composition.

## Core Explanation

Popular gateways: Kong (Lua/OpenResty), AWS API Gateway, Azure API Management, Apigee, Envoy (Lyft, graduated CNCF). BFF (Backend for Frontend) pattern: dedicated gateway per client type. API Gateway vs. Service Mesh: gateway handles north-south traffic (client→server); service mesh handles east-west (service→service).

## Further Reading

- [Kong Gateway Documentation](https://docs.konghq.com/)