Set up API Gateway for Lambda Function

To set up API Gateway for a Lambda function, you can either use the Lambda console for quick setup or the API Gateway console for more customization.

Here’s a detailed walkthrough of both methods:

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🛠️ Method 1: Setup via Lambda Console (Quick & Easy)

1. Create your Lambda function
   • Go to the AWS Lambda console.
   • Click “Create function” and configure runtime, permissions, and code.
2. Add API Gateway trigger
   • In the Lambda function page, scroll to “Function overview.”
   • Click “+ Add trigger” → Select API Gateway.
   • Choose Create an API → Select HTTP API (lightweight) or REST API (more features).
   • Click “Add” to create and link the API Gateway.
3. Test your endpoint
   • After setup, you’ll see an Invoke URL under the trigger.
   • Use tools like Postman or curl to send HTTP requests to this URL.

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⚙️ Method 2: Setup via API Gateway Console (Customizable)

1. Create an API
   • Go to the API Gateway console.
   • Choose HTTP API or REST API depending on your needs.
   • Click “Create API” and name it.
2. Add a resource and method
   • For REST API: Create a resource (e.g., /hello) and add a method (e.g., GET or POST).
   • For HTTP API: Define routes directly (e.g., /hello with POST method).
3. Integrate with Lambda
   • Choose Lambda function as the integration type.
   • Select your function and grant API Gateway permission to invoke it.
4. Deploy the API
   • Create a stage (e.g., dev, prod) and deploy your API.
   • You’ll get a public Invoke URL for testing.

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🔐 Optional Enhancements

• Enable CORS if your API will be accessed from browsers.
• Add authentication using IAM, Cognito, or custom authorizers.
• Monitor usage with CloudWatch metrics and logging.

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📚 Helpful Resources

• AWS Official Guide
• Step-by-step tutorial with examples
• Baeldung’s integration overview