【AWS】AWS SAM CLIでLambda×API GatewayのサーバーレスAPIを作る方法

sam init

Which template source would you like to use?
    1 - AWS Quick Start Templates
Choice: 1

Choose an AWS Quick Start application template
    1 - Hello World Example
Template: 1

Use the most popular runtime and package type? (Python and zip) [y/N]: y

Would you like to enable X-Ray tracing on the function(s) in your application? [y/N]: n

Project name [sam-app]: sam-lambda-api

sam-lambda-api/
├── hello_world/
│   ├── app.py
│   └── requirements.txt
├── events/
│   └── event.json
└── template.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: sam-lambda-api

Globals:
  Function:
    Timeout: 10
    Runtime: python3.13

Resources:
  HelloWorldFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: hello_world/
      Handler: app.lambda_handler
      Events:
        HelloWorld:
          Type: Api
          Properties:
            Path: /hello
            Method: get

Outputs:
  HelloWorldApi:
    Description: API Gateway endpoint URL
    Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/hello/"

import json

def lambda_handler(event, context):
    return {
        "statusCode": 200,
        "body": json.dumps({"message": "Hello from Lambda!"})
    }

sam deploy --guided