api-gateway

# AWS API Gateway

Amazon API Gateway is a fully managed service for creating, publishing, and securing APIs at any scale. Supports REST APIs, HTTP APIs, and WebSocket APIs.

## Table of Contents

- [Core Concepts](#core-concepts)
- [Common Patterns](#common-patterns)
- [CLI Reference](#cli-reference)
- [Best Practices](#best-practices)
- [Troubleshooting](#troubleshooting)
- [References](#references)

## Core Concepts

### API Types

| Type | Description | Use Case |
|------|-------------|----------|
| **HTTP API** | Low-latency, cost-effective | Simple APIs, Lambda proxy |
| **REST API** | Full-featured, more control | Complex APIs, transformation |
| **WebSocket API** | Bidirectional communication | Real-time apps, chat |

### Key Components

- **Resources**: URL paths (/users, /orders/{id})
- **Methods**: HTTP verbs (GET, POST, PUT, DELETE)
- **Integrations**: Backend connections (Lambda, HTTP, AWS services)
- **Stages**: Deployment environments (dev, prod)

### Integration Types

| Type | Description |
|------|-------------|
| **Lambda Proxy** | Pass-through to Lambda (recommended) |
| **Lambda Custom** | Transform request/response |
| **HTTP Proxy** | Pass-through to HTTP endpoint |
| **AWS Service** | Direct integration with AWS services |
| **Mock** | Return static response |

## Common Patterns

### Create HTTP API with Lambda

**AWS CLI:**

```bash
# Create HTTP API
aws apigatewayv2 create-api \
  --name my-api \
  --protocol-type HTTP \
  --target arn:aws:lambda:us-east-1:123456789012:function:MyFunction

# Get API endpoint
aws apigatewayv2 get-api --api-id abc123 --query 'ApiEndpoint'
```

**SAM Template:**

```yaml
AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31

Resources:
  MyApi:
    Type: AWS::Serverless::HttpApi
    Properties:
      StageName: prod

  MyFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: app.handler
      Runtime: python3.12
      Events:
        ApiEvent:
          Type: HttpA