ChainForge

Educational Blockchain Implementation - Learn blockchain fundamentals through hands-on development with Ruby, Sinatra, and MongoDB.

A blockchain implementation with Proof of Work mining, REST API, and comprehensive security features. ChainForge demonstrates core blockchain concepts including cryptographic hashing, chain validation, and immutability through a clean, well-tested Ruby codebase.

Features

• ✅ Proof of Work Mining - Configurable difficulty (1-10)
• ✅ RESTful API - Versioned endpoints (/api/v1)
• ✅ Chain Integrity - SHA256 hashing and validation
• ✅ Security - Rate limiting, input validation
• ✅ Well-Tested - RSpec tests with >90% coverage
• ✅ CI/CD - Automated testing and linting

Quick Start

Prerequisites

• Ruby 3.2.2
• MongoDB
• Docker (optional)

Installation

# Clone repository
git clone https://github.com/Perafan18/chain_forge.git
cd chain_forge

# Install dependencies
bundle install

# Configure environment
cp .env.example .env

# Start MongoDB (or use Docker)
brew services start mongodb-community  # macOS
# Or: docker-compose up -d db

# Run application
ruby main.rb -p 1910

Using Docker (Recommended)

docker-compose up

Application will be available at http://localhost:1910

Your First Blockchain

# Create blockchain
curl -X POST http://localhost:1910/api/v1/chain
# Returns: {"id":"674c8a1b2e4f5a0012345678"}

# Mine a block
curl -X POST http://localhost:1910/api/v1/chain/674c8a1b2e4f5a0012345678/block \
  -H 'Content-Type: application/json' \
  -d '{"data": "Hello, Blockchain!", "difficulty": 2}'

# Returns: {
#   "chain_id": "674c8a1b2e4f5a0012345678",
#   "block_id": "674c8b2c3e5f6a0012345679",
#   "block_hash": "00a1b2c3d4e5f6789...",
#   "nonce": 142,
#   "difficulty": 2
# }

Documentation

Comprehensive documentation is available in the docs/ folder:

Getting Started

• Installation Guide - Detailed setup instructions
• Quick Start Tutorial - Create your first blockchain in 5 minutes
• First Blockchain Tutorial - Complete walkthrough with mining

Architecture & Design

• System Overview - High-level architecture and data flow
• Proof of Work Deep Dive - Mining algorithm explained
• Data Models - MongoDB schema and relationships
• Security Design - Security layers and threat model

API Documentation

• API Reference - Complete endpoint documentation
• Code Examples - Integration examples (Python, JavaScript, Ruby, curl)
• Rate Limiting - Understanding and handling rate limits

Developer Guides

• Development Setup - Complete development environment guide
• Testing Guide - RSpec, coverage, and CI/CD
• Deployment Guide - Production deployment
• Troubleshooting - Common issues and solutions

Project Information

• CHANGELOG - Version history
• CONTRIBUTING - How to contribute
• SECURITY - Security policies
• CLAUDE - Claude Code development guide

API Endpoints

All endpoints are prefixed with /api/v1:

Endpoint	Method	Description	Rate Limit
/chain	POST	Create new blockchain	10/min
/chain/:id/block	POST	Mine and add block	30/min
/chain/:id/block/:block_id	GET	Get block details	60/min
/chain/:id/block/:block_id/valid	POST	Validate block data	60/min

See API Reference for complete documentation.

Development

Run Tests

# Run all tests
bundle exec rspec

# Run with coverage
COVERAGE=true bundle exec rspec

# View coverage report
open coverage/index.html

Code Quality

# Run linter
bundle exec rubocop

# Auto-fix issues
bundle exec rubocop -a

CI/CD

GitHub Actions runs automatically on push and PR:

• ✅ RuboCop linting
• ✅ RSpec test suite
• ✅ Coverage reporting

Educational Project

ChainForge is designed for learning blockchain fundamentals and is NOT intended for production use.

Learn:

• ✅ Blockchain concepts (hashing, chain validation, immutability)
• ✅ Proof of Work mining algorithm
• ✅ API security (rate limiting, input validation)
• ✅ Ruby/Sinatra development
• ✅ MongoDB/Mongoid ODM
• ✅ Testing and CI/CD best practices

Do NOT use for:

• ❌ Production applications
• ❌ Cryptocurrency implementation
• ❌ Storing valuable data
• ❌ Distributed systems

For production blockchains, study Bitcoin or Ethereum implementations.

Contributing

Contributions are welcome! This is a learning project focused on understanding blockchain fundamentals.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/my-feature)
3. Write tests for your changes
4. Ensure tests pass (bundle exec rspec)
5. Ensure code quality (bundle exec rubocop)
6. Commit your changes (git commit -m 'feat: Add my feature')
7. Push to the branch (git push origin feature/my-feature)
8. Open a Pull Request

See CONTRIBUTING for detailed guidelines.

License

MIT License - see LICENSE file for details.

Acknowledgments

Built as a learning exercise to understand blockchain technology fundamentals. Special thanks to the blockchain community for educational resources and inspiration.

Version

Current Version: 2.0.0

See CHANGELOG for version history.

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Ready to start? Check out the Quick Start Tutorial!