URL Shortener using AWS Lambda, API Gateway & DynamoDB

This project is a serverless URL Shortener built using AWS Lambda, Amazon API Gateway, Amazon DynamoDB, and TypeScript. It allows users to generate short URLs for long URLs and handle redirections efficiently.

Features

• Generate short URLs for long links
• Redirect users from short URLs to original URLs
• Store mappings in DynamoDB with shortCode as the primary key
• Implement error handling for invalid requests
• Deployed using AWS Serverless Application Model (SAM)
• Uses AWS SDK v3 for DynamoDB interactions

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Tech Stack

• AWS Lambda (Node.js 22.x)
• Amazon API Gateway
• Amazon DynamoDB (On-Demand Billing Mode)
• TypeScript
• AWS SDK v3
• AWS SAM (for deployment)
• Thunder Client (for API testing)

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Prerequisites

Before running the project, ensure you have the following:

• Node.js installed
• AWS Account with programmatic access configured
• AWS CLI installed and configured
• AWS SAM CLI installed for deployment

DynamoDB Table Configuration

Attribute Name	Type
shortCode	String
url	String

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📄 Project Structure

├── hello-world
│   ├── app.ts          # Lambda function handler
│   ├── package.json    # Dependencies
│   ├── tsconfig.json   # TypeScript Configuration
│   └── node_modules    # Installed packages (after npm install)
├── template.yaml       # AWS SAM template defining resources
└── README.md           # Project documentation

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⚙️ Setup & Installation

1️⃣ Clone Repository

git clone https://github.com/AbhijeetAayush/Url-Shortener-AWS.git
cd Url-Shortener-AWS

2️⃣ Install Dependencies

npm install

3️⃣ Deploy to AWS using AWS SAM

1. Build the application:

   sam build

2. Deploy using AWS SAM CLI:

   sam deploy --guided

   Follow the prompts to configure your deployment settings.

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🔥 API Endpoints

1️⃣ Shorten URL

• Endpoint:

  POST /shorten

• Request Body:

  {
    "url": "https://example.com"
  }

• Response:

  {
    "shortUrl": "https://{api-gateway-url}/Prod/abc123"
  }

2️⃣ Redirect to Original URL

• Endpoint:

  GET /{shortCode}

• Behavior: Redirects to the original URL stored in DynamoDB.

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🎯 Testing with Thunder Client (VSCode Extension)

1. Install the Thunder Client extension.
2. Send a POST request to /shorten with a JSON body containing a url.
3. Use the returned short URL in a GET request to test redirection.

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💪 Error Handling & Responses

Status Code	Message
400	Missing request body
400	Missing URL
400	ShortCode is required
404	Short URL not found
500	Internal Server Error

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📌 Environment Variables

Name	Description
TABLE_NAME	DynamoDB table name storing URLs

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📌 Logs & Monitoring

• CloudWatch Logs: View execution logs in AWS CloudWatch for debugging.
• SAM Logs: Run the following to fetch logs locally:

  sam logs -n HelloWorldFunction --tail

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📌 AWS SAM Template (template.yaml)

The AWS Serverless Application Model (SAM) template defines the infrastructure:

• AWS Lambda Function (hello-world/app.ts as handler)
• API Gateway Endpoints (/shorten for POST, /{shortCode} for GET)
• DynamoDB Table (ShortenedURLs with shortCode as primary key)
• IAM Policies for Lambda to interact with DynamoDB

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📜 License

This project is licensed under the MIT License.