API Gateway
A server that acts as a single entry point for a set of backend APIs or microservices, handling request routing, authentication, rate limiting, and protocol translation.
In-Depth Explanation
An API gateway is a reverse proxy that sits between clients and backend services, providing a unified interface for accessing multiple APIs. It centralises cross-cutting concerns like authentication, rate limiting, logging, and protocol translation.
Key API gateway functions:
- Request routing: Directing requests to the appropriate backend service based on URL path, headers, or other attributes
- Authentication and authorisation: Verifying API keys, JWT tokens, or OAuth credentials before forwarding requests
- Rate limiting: Controlling request volume to prevent abuse and protect backends
- Protocol translation: Converting between protocols (e.g., REST to gRPC, HTTP to WebSocket)
- Request/response transformation: Modifying request or response payloads as needed
- Caching: Caching common responses to reduce backend load
- Load balancing: Distributing requests across multiple backend instances
- Monitoring and logging: Centralised request logging and analytics
Popular API gateway solutions:
- AWS API Gateway: Managed service integrated with Lambda and other AWS services
- Azure API Management: Enterprise API management with developer portal
- Google Cloud API Gateway: Managed gateway for Google Cloud
- Kong: Open-source, highly extensible gateway
- Nginx/Envoy: High-performance reverse proxies used as API gateways
- Cloudflare Workers: Edge-based API gateway capabilities
API gateway patterns:
- Backend for Frontend (BFF): Different gateways optimised for different clients (web, mobile)
- Gateway aggregation: Combining multiple backend calls into a single client response
- Gateway offloading: Moving cross-cutting concerns from services to the gateway
Business Context
API gateways simplify client integrations, centralise security enforcement, and provide visibility into API usage, making them essential for businesses exposing APIs or running microservices.
How Clever Ops Uses This
Clever Ops implements API gateways for Australian businesses, centralising authentication, rate limiting, and monitoring for APIs that power web applications, mobile apps, and third-party integrations.
Example Use Case
"A SaaS company implements AWS API Gateway in front of their microservices, centralising JWT authentication, applying per-customer rate limits, and gaining unified API usage analytics across all services."