DynamoTalk - Serverless Chat Application

A real-time chat application built with AWS serverless services, Next.js, and Tailwind CSS.

Architecture

This application uses AWS serverless services for scalability and cost-effectiveness:

Backend Services:

• AWS Lambda - API logic and message processing
• DynamoDB - Message storage and user data
• API Gateway - RESTful API endpoints
• WebSocket API - Real-time communication
• Cognito - User authentication
• S3 - File uploads and avatars
• CloudFront - Content delivery

Frontend:

• Next.js 14 with App Router
• TypeScript
• Tailwind CSS
• AWS SDK integration

Database Design

Users Table

PK: USER#{userId}
Attributes: username, email, avatar, createdAt, lastSeen

Rooms Table

PK: ROOM#{roomId}
Attributes: name, description, type, createdBy, members[]

Messages Table

PK: ROOM#{roomId}
SK: MESSAGE#{timestamp}#{messageId}
Attributes: userId, content, messageType, attachments

Connections Table

PK: CONNECTION#{connectionId}
Attributes: userId, roomId, connectedAt

Getting Started

1. Install Dependencies

npm install

2. Deploy AWS Infrastructure

npm run infra:deploy

This creates all AWS resources (Cognito, DynamoDB) automatically.

3. Configure Environment

Copy the output values to .env.local - see INFRASTRUCTURE.md for details.

4. Start Development

npm run dev

Infrastructure Management

npm run infra:deploy   # Deploy AWS infrastructure
npm run infra:diff     # Preview changes
npm run infra:destroy  # Remove all AWS resources

Project Structure

src/
├── app/                 # Next.js App Router
├── components/          # React components
├── lib/                # Utilities and AWS config
└── types/              # TypeScript definitions

infrastructure/
├── lib/                # CDK stack definitions
└── bin/                # CDK app entry point

scripts/                # Deployment scripts