Dauphin 🐬

A lightweight and clean BitTorrent client written in Node.js.

Features

• Pure JavaScript implementation (no external torrent libraries)
• HTTP and UDP tracker support
• Peer wire protocol implementation
• Piece verification with SHA-1 hashing
• Clean command-line interface
• Progress tracking

Installation

Global Installation (Recommended)

Install globally to use the dauphin command anywhere:

npm install -g dauphin

Local Installation

Install in your project:

npm install dauphin

From Source

Clone and install:

git clone https://github.com/yourusername/dauphin.git
cd dauphin
npm install
npm link

Usage

Basic Usage

dauphin <torrent-file>

With Options

# Specify output directory
dauphin file.torrent -o ~/Downloads

# Enable debug mode
dauphin file.torrent --debug

# Show help
dauphin --help

# Show version
dauphin --version

Options

• -o, --output <dir> - Output directory for downloads (default: ./downloads)
• -h, --help - Show help message
• -v, --version - Show version number
• --debug - Enable debug mode with detailed error output

Examples

Download Ubuntu ISO:

dauphin ubuntu.torrent

Download to specific folder:

dauphin movie.torrent --output /media/downloads

Architecture

• src/index.js - CLI entry point
• src/torrent-parser.js - Parses .torrent files (bencode decoding)
• src/tracker.js - Communicates with trackers (HTTP/UDP)
• src/peer.js - Handles peer connections and wire protocol
• src/pieces.js - Manages piece selection and verification
• src/downloader.js - Coordinates the download process
• src/utils.js - Utility functions

Protocol Support

• BitTorrent Protocol (BEP 3)
• HTTP Tracker Protocol
• UDP Tracker Protocol (BEP 15)

Development

Running Tests

npm test

Running in Watch Mode

npm run test:watch

Running from Source

npm start -- file.torrent -o ./downloads

Requirements

• Node.js >= 18.0.0

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT