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AWS API Gateway

Modern applications rely on APIs to connect services, share data, and deliver seamless digital experiences. But as APIs grow in number and complexity, managing them becomes a challenge — especially at scale.
That’s where AWS API Gateway comes in. 

It is a fully managed service from Amazon Web Services that makes it easy to create, publish, maintain, monitor, and secure APIs. It acts as a front door for applications to access data, business logic, or functionality from backend services, such as AWS Lambda, EC2, or on-premise systems. 

In simple terms, AWS API Gateway helps you build and manage RESTful APIs and WebSocket APIs without worrying about infrastructure. It handles everything — from traffic management and security to monitoring and version control — allowing developers to focus on building functionality, not managing servers. 

What is AWS API Gateway? 

AWS API Gateway is a fully managed service from Amazon Web Services that helps developers create, publish, secure, monitor, and manage APIs at scale. 

It acts as a front door for applications to access data or functionality from backend services such as AWS Lambda, EC2 instances, or on-premises systems. 

With API Gateway, you can build RESTful APIs, HTTP APIs, or WebSocket APIs that connect different services and clients — including web, mobile, and IoT applications. 

In short:
AWS API Gateway provides a simple way to create and manage APIs without provisioning or maintaining servers. It handles: 

• API traffic routing 

• Authorization and authentication 

• Request and response transformation 

• Monitoring and logging 

• Caching, throttling, and rate limiting 

It’s a key part of AWS’s serverless architecture, often used alongside AWS Lambda for building scalable, low-maintenance applications. 

 

How AWS API Gateway Works 

It sits between your client applications and backend systems. It processes incoming requests, applies rules (security, throttling, caching), and routes the request to the correct backend. 

Here’s a step-by-step breakdown of how it works: 

• API Definition: 

• You define endpoints, methods (GET, POST, PUT, DELETE), and request/response schemas. 

• Integration: 

• Connect the API to AWS Lambda, EC2, DynamoDB, or any HTTP backend. 

• Security: 

• Use AWS IAM, Cognito, or custom authorizers for authentication. 

• Deployment: 

• Deploy APIs into different stages like dev, test, and prod. 

• Traffic Handling: 

• API Gateway scales automatically based on request volume. 

• Monitoring: 

• Use Amazon CloudWatch to track metrics, latency, and errors. 

Essentially, API Gateway handles everything from request validation to execution — allowing developers to focus on logic, not infrastructure. 

 

AWS API Gateway Features 

AWS API Gateway comes with powerful features designed to support modern, scalable, and secure applications: 

• Multi-Protocol Support – Build REST, HTTP, or WebSocket APIs. 

• Automatic Scaling – Scales automatically to handle thousands or millions of requests per second. 

• Built-In Security – Integrates with AWS Identity and Access Management (IAM), Cognito, and SSL/TLS. 

• Request Validation and Transformation – Validate payloads and transform data before forwarding. 

• Caching – Reduce backend load and latency by caching responses. 

• Throttling and Quotas – Prevent abuse by controlling request rates and usage limits. 

• Custom Domains – Use your own domain name with SSL certificates. 

• Monitoring and Logging – View metrics and logs through Amazon CloudWatch. 

• Versioning and Stages – Manage multiple API versions easily. 

• Seamless AWS Integration – Works natively with Lambda, DynamoDB, S3, SNS, and more. 

Together, these features make AWS API Gateway a complete API management solution for cloud-native and hybrid applications. 

 

AWS API Gateway Pricing 

AWS API Gateway uses a pay-as-you-go pricing model — you only pay for what you use.
Pricing depends on API type (REST, HTTP, or WebSocket) and the number of requests. 

Here’s a simplified overview: 

1. REST APIs 

• $3.50 per million requests (after the free tier). 

• Additional charges for data transfer, caching, and custom domain usage. 

2. HTTP APIs 

• $1.00 per million requests, making it more cost-effective for most workloads. 

• Lower latency and cheaper than REST APIs. 

3. WebSocket APIs 

• Billed based on the number of messages and connection minutes. 

4. Free Tier 

• 1 million API calls per month for the first 12 months. 

Other cost factors: 

• Caching: $0.02 per GB-hour. 

• Data transfer out: Standard AWS transfer rates apply. 

• Custom Domain Names: Billed per regional endpoint. 

Tip: Use HTTP APIs for simpler serverless integrations (e.g., with Lambda) to reduce costs by up to 70%. 

 

What Are the Benefits of AWS API Gateway? 

AWS API Gateway offers a wide range of business and technical benefits: 

• Fully Managed Service – No need to provision or manage servers. 

• Scalability on Demand – Automatically handles high traffic volumes. 

• Security and Compliance – Built-in IAM, Cognito, and encryption support. 

• Reduced Latency – Response caching and AWS edge integration improve performance. 

• Cost Efficiency – Pay only for API calls and data transfer. 

• Simplified Deployment – Manage multiple environments (dev, test, prod) easily. 

• Integration with AWS Ecosystem – Works seamlessly with Lambda, DynamoDB, S3, and CloudFront. 

• Developer Productivity – Frees developers from infrastructure management. 

It’s particularly powerful for microservices, mobile backends, and serverless applications, where scalability and low overhead are crucial. 

 

AWS API Gateway vs Load Balancer 

Both AWS API Gateway and AWS Load Balancer (ALB/NLB) handle network traffic — but they serve very different purposes. 

Aspect	AWS API Gateway	AWS Load Balancer (ALB/NLB)
Purpose	API management and request routing	Traffic distribution across servers
Best For	APIs, serverless apps, microservices	Web apps, container clusters, EC2 services
Integration	Works with Lambda, DynamoDB, and other AWS services	Works mainly with EC2, ECS, and EKS
Protocol Support	HTTP, REST, WebSocket	HTTP, HTTPS, TCP, UDP
Authentication	Supports IAM, Cognito, OAuth 2.0	No native authentication layer
Caching	Built-in response caching	No caching capabilities
Developer Tools	API versioning, transformation, metrics	Traffic routing and health checks
Pricing Model	Pay per API call	Pay per hour/throughput capacity

In summary: 

• Use API Gateway for API-driven architectures and serverless applications. 

• Use Load Balancer for distributing incoming traffic to backend servers or containers. 

 

What is the Difference Between REST, HTTP, and WebSocket APIs in API Gateway? 

AWS API Gateway supports three main types of APIs — each designed for different use cases and performance needs. 

API Type	Description	Use Case
REST API	Traditional API structure using HTTP methods (GET, POST, etc.). Includes caching, request validation, and API keys.	Legacy systems, complex integrations, enterprise APIs.
HTTP API	Modern, faster, and more cost-effective version of REST API. Lower latency and simplified configuration.	Serverless apps, Lambda integrations, lightweight APIs.
WebSocket API	Enables full-duplex (two-way) communication between client and server.	Real-time apps like chat, gaming, IoT, and live dashboards.

Quick tip: 

• Choose HTTP APIs for most new projects — they’re cheaper and faster. 

• Use WebSocket APIs when you need real-time, persistent connections. 

Conclusion 

It is the backbone of API management in the AWS ecosystem — offering scalability, security, and simplicity for building and managing APIs at any scale.
It empowers developers to create high-performance, cost-efficient APIs without managing infrastructure, perfectly complementing serverless architectures and microservices. 

Whether powering web apps, mobile backends, or IoT systems, AWS API Gateway ensures that your APIs are fast, reliable, and future-ready — built for the cloud and optimized for innovation. 

Related Terms:

• API Gateway

• AWS Lambda

• Serverless Computing