A Comprehensive Guide to AWS API Gateway Documentation

AWS API Gateway has gotten complicated with all the API types, integration options, and authentication mechanisms flying around. As someone who has built and managed hundreds of APIs using API Gateway in production, I learned everything there is to know about this service. Today, I will share it all with you.

API Gateway is one of those services that seems simple at first — you create an API, define some endpoints, connect them to Lambda or HTTP backends — but the depth of configuration options and the nuances of production deployment can surprise you. Let me walk you through what actually matters.

Components of API Gateway

Probably should have led with this section, honestly. API Gateway comes in three flavors, and choosing the right one matters:

• REST API: The full-featured option. Supports request/response transformation, API keys, usage plans, caching, and WAF integration. This is what I use for most public-facing APIs that need comprehensive management features.
• HTTP API: The lightweight, cheaper alternative. Up to 71% less expensive than REST APIs, with lower latency. Supports JWT authorization natively. I use HTTP APIs for internal microservice communication and simple APIs where I don’t need the advanced features of REST APIs.
• WebSocket API: For real-time, two-way communication. Chat applications, live dashboards, gaming backends, and IoT data streaming. A completely different animal from REST and HTTP APIs.

The choice between REST and HTTP APIs trips up a lot of people. My rule of thumb: if you need request transformation, API keys with usage plans, or resource policies, use REST API. For everything else, HTTP API is simpler, faster, and cheaper.

Setting Up Your API Gateway

That’s what makes API Gateway endearing to us backend developers — the setup process is straightforward but gives you production-grade API infrastructure in minutes. You define resources (URL paths), methods (GET, POST, PUT, DELETE), and integrations (what processes each request).

Here’s my typical setup process for a new REST API:

1. Create the API and define the resource hierarchy
2. Add methods to each resource with the appropriate integration type
3. Configure request validation and transformation if needed
4. Set up CORS for browser-based clients
5. Add authorization (Cognito, Lambda authorizer, or IAM)
6. Deploy to a stage (dev, staging, prod)
7. Configure custom domain name with ACM certificate
8. Set up API keys and usage plans for rate limiting

Deploy through CloudFormation or SAM, not the console. Console deployments are fine for learning, but production APIs need repeatable, version-controlled deployments.

Integration Options

API Gateway supports several backend integration types:

• Lambda Integration (Proxy): The most common pattern. API Gateway passes the entire request to Lambda and returns the Lambda response directly. Simple, flexible, and my default choice for serverless APIs.
• Lambda Integration (Non-Proxy): Allows you to transform the request before it reaches Lambda and transform the response before it goes back to the client. More setup work but useful when you need to reshape data between API consumers and your backend.
• HTTP Integration: Forward requests to an HTTP endpoint — an ALB, an EC2 instance, or any external URL. I use this for APIs that front existing backend services.
• AWS Service Integration: Connect directly to AWS services like SQS, Step Functions, or DynamoDB without Lambda in between. This can reduce latency and cost for simple operations.
• Mock Integration: Return a hardcoded response without a backend. Useful for development and testing, and for health check endpoints that don’t need backend logic.

The direct AWS service integration is underused in my opinion. For simple operations like putting a message on an SQS queue or writing to DynamoDB, skipping Lambda entirely reduces latency, cost, and complexity. I’ve converted several Lambda-backed endpoints to direct service integrations with excellent results.

Security Features

API security isn’t optional, and API Gateway provides multiple layers of protection:

• IAM Authorization: Uses AWS IAM policies and Signature V4 for request signing. Best for service-to-service communication within AWS.
• Amazon Cognito Authorizers: Validates JWT tokens from Cognito User Pools. Perfect for user-facing applications where you need authentication and user management.
• Lambda Authorizers: Custom authorization logic in a Lambda function. I use these when I need to validate tokens from third-party identity providers or implement complex authorization logic that goes beyond simple JWT validation.
• API Keys: Identify callers and enforce usage plans. Not a security mechanism on their own (API keys can be shared), but useful for tracking and throttling.
• Resource Policies: IAM-like policies that control which principals can invoke your API. Useful for restricting access to specific VPCs, accounts, or IP ranges.
• WAF Integration: Attach a WAF Web ACL to protect against common web exploits. I enable this for every internet-facing REST API.
• Mutual TLS: Client certificate authentication for high-security APIs. Requires more setup but provides strong identity verification.

Monitoring and Logging

API Gateway integrates with CloudWatch for both logging and metrics. Enable execution logging to capture the full request/response cycle, including headers, body, and latency breakdown. Access logging captures structured logs in a format you define — I use JSON format and send logs to CloudWatch for analysis with Logs Insights.

Key metrics to monitor: 4XXError and 5XXError counts, latency (integration latency vs API Gateway latency), cache hit ratio (if caching is enabled), and throttling counts. Set up CloudWatch alarms for error rate spikes and latency increases. These are the metrics that tell you when something is going wrong before your users complain.

X-Ray integration provides distributed tracing across API Gateway, Lambda, and downstream services. Enable it for debugging latency issues in complex request flows.

Best Practices

After years of working with API Gateway in production, these are the practices I follow consistently:

• Use stages and stage variables for environment separation
• Enable request validation to reject malformed requests before they reach your backend
• Set up throttling limits at the API, stage, and method level to protect your backend
• Use custom domain names with Route 53 alias records
• Enable caching for GET endpoints with stable responses to reduce Lambda invocations
• Deploy with canary releases when making significant changes
• Document your APIs with OpenAPI specifications

Conclusion

API Gateway is the front door for your APIs on AWS, and investing time in understanding its features pays dividends in security, performance, and operational efficiency. Whether you’re building a simple serverless API or a complex multi-service architecture, API Gateway provides the management, security, and scalability layers that production APIs require. Start with HTTP APIs for simplicity, graduate to REST APIs when you need advanced features, and always deploy through infrastructure as code.