Number Classification API

Overview

The Number Classification API is a serverless application hosted on AWS Lambda and exposed via API Gateway. It takes a number as a query parameter and returns interesting mathematical properties, including whether the number is prime, perfect, an Armstrong number, and a fun fact.

Prerequisites

• An AWS account
• Basic knowledge of AWS Lambda and API Gateway

Features

• Determines if a number is prime and perfect.
• Identifies special properties like Armstrong and odd/even.
• Computes the sum of digits.
• Fetches a fun fact about the number from Numbers API.
• Handles CORS for cross-origin requests.
• Returns JSON responses with appropriate HTTP status codes.

API Specification

Endpoint:

GET <your-api-url>/api/classify-number?number=371

Response Example (200 OK):

{
    "number": 371,
    "is_prime": false,
    "is_perfect": false,
    "properties": ["armstrong", "odd"],
    "digit_sum": 11,
    "fun_fact": "371 is an Armstrong number because 3^3 + 7^3 + 1^3 = 371"
}

Response Example (400 Bad Request):

{
    "number": "invalid_input",
    "error": true
}

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Deployment Guide

This guide walks you through deploying the Number Classification API on AWS using AWS Lambda and API Gateway (REST API).

1. Create an AWS Lambda Function

1. Sign in to the AWS Management Console.
2. Navigate to AWS Lambda and click Create function.
3. Select Author from scratch and enter:
   • Function name: NumberClassificationAPI
   • Runtime: Python 3.x
   • Execution role: Create a new role with basic Lambda permissions.
4. Click Create function.

2. Upload the Lambda Code

1. In the Lambda function page, go to Code and click Upload from → .zip file.
2. Upload the ZIP file containing your function code and dependencies (ensure requests is included).
3. Set Handler - Ensure the handler name matches your main function (e.g., lambda_function.lambda_handler if your file is lambda_function.py)
4. • Click Deploy

3. Set Up API Gateway (REST API)

1. Navigate to API Gateway

   • Go to the AWS Management Console
   • Search for API Gateway and open the service

2. Create a New API

   • Click Create API
   • Select REST API (not HTTP or WebSocket)
   • Choose Build
   • Set an API name (e.g., NumberClassificationAPI)
   • Click Create API

3. Create a New Resource

   • In the Resources section, click Actions → Create Resource
   • Set Resource Name: classify-number
   • Click Create Resource

4. Create a Method (GET)

   • Select the classify-number resource
   • Click Actions → Create Method
   • Choose GET and click the checkmark
   • In the Integration Type, select Lambda Function
   • Enter the name of your Lambda function (e.g., NumberClassificationAPI)
   • Click Save and confirm the permissions

5. Enable Lambda Proxy Integration

   • Select the GET method
   • Check Use Lambda Proxy Integration
   • Click Save

4. Enable CORS in API Gateway

1. In API Gateway, navigate to your API and go to CORS settings.

2. Set allowed origins to *.

3. Set allowed methods to GET.

4. Add response headers:

   • Access-Control-Allow-Headers: Content-Type
   • Access-Control-Allow-Methods: GET
   • Access-Control-Allow-Origin: *

5. Save

6. Create a Deployment Stage

   • Click Actions → Deploy API
   • Create a new stage (e.g., prod)
   • Click Deploy

7. Get the Invoke URL

   • After deployment, copy the Invoke URL from the Stages section
   • Your API will be accessible at:

     https://your-api-id.execute-api.your-region.amazonaws.com/prod/api/classify-number?number=371
     

5. Test the API

1. Copy your Invoke URL from API Gateway.
2. Test the API using a browser, Postman, or curl:

   curl -X GET "<your-api-url>/api/classify-number?number=371"

3. Ensure you receive a valid JSON response.

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Conclusion

Your Number Classification API is now fully deployed and accessible. 🚀 Test your endpoint, validate responses, and share your API URL.

Happy coding! 🎉