Fee Calculator API

A TypeScript/Express.js API for calculating fees based on time periods, with Swagger documentation.

Features

• Calculate fees for daily or monthly periods
• RESTful API with comprehensive error handling
• Swagger/OpenAPI documentation
• TypeScript for type safety
• Ready for deployment on Render

API Endpoints

• GET / - Health check endpoint
• GET /api/ - API health check
• POST /api/feeCalc - Calculate fees based on parameters
• GET /api-docs - Swagger UI documentation

Local Development

Prerequisites

• Node.js >= 18.0.0
• npm (included with Node.js)

Setup

1. Clone the repository

2. Install dependencies:

   npm install

3. Run in development mode:

   npm run dev

4. Build for production:

   npm run build

5. Start production server:

   npm start

The server will run on http://localhost:3000 by default.

Fee Calculation API Usage

Endpoint: POST /api/feeCalc

Calculate fees based on time period and amount.

Query Parameters:

• days (integer, optional): Number of days (use when isMonthly=false)
• months (integer, optional): Number of months (use when isMonthly=true)
• isMonthly (boolean, required): Whether to calculate monthly fees
• fees (number, required): Fee percentage
• money (number, required): Base amount to calculate fees on

Example Requests:

Daily calculation:

curl -X POST "http://localhost:3000/api/feeCalc?days=10&isMonthly=false&fees=2.5&money=1000"

Monthly calculation:

curl -X POST "http://localhost:3000/api/feeCalc?months=3&isMonthly=true&fees=5&money=2000"

Response:

"250$ in 10 days"

Project Structure

├── src/
│   ├── index.ts           # Main application entry point
│   ├── api/
│   │   └── api.ts         # API routes and documentation
│   └── functions/
│       └── feeCalculator.ts # Core calculation logic
├── dist/                  # Compiled JavaScript (generated)
├── package.json           # Dependencies and scripts
├── tsconfig.json          # TypeScript configuration
├── render.yaml            # Render deployment configuration
└── README.md              # This file

Development Scripts

• npm run dev - Start development server with hot reload
• npm run build - Compile TypeScript to JavaScript
• npm start - Start production server
• npm run postinstall - Automatically runs build after install

Dependencies

Production

• express - Web framework
• swagger-jsdoc - Generate Swagger specs from JSDoc
• swagger-ui-express - Serve Swagger UI
• prompt-sync - Console input utility

Development

• typescript - TypeScript compiler
• @types/* - Type definitions
• ts-node - TypeScript execution for development
• nodemon - Development server with auto-restart

License

MIT License