🤖 Bender - Automated Cryptocurrency Trading Bot for Bitvavo

An open-source crypto trading bot that automates your trading on the Bitvavo exchange. Bender uses technical analysis (RSI, MACD, Bollinger Bands) to execute trades 24/7, featuring multi-market portfolio management, risk controls, and both paper trading and live trading modes.

🧪 A Vibe Coding Origin Story

Bender started as my first "vibe coding" experiment. What began as copy-pasting functions and classes through Claude's chat interface—iterating piece by piece, asking "can you add this?" and "what if we did that?"—has evolved into a fully-fledged trading bot built with Claude Code.

The journey from scattered code snippets in a chat window to a structured project with proper testing, architecture, and documentation has been a testament to how AI-assisted development is changing the way we build software. This project represents the full spectrum: from the earliest days of prompting for individual functions, to now having an AI pair programmer that understands the entire codebase.

🌟 Why Bender?

Ever wished you had a reliable companion to handle your crypto trading while you focus on what matters most to you? That's exactly why I created Bender! As someone passionate about both cryptocurrency and automation, I wanted to share a tool that makes trading more accessible and less time-consuming for everyone.

🎯 What Makes Bender Special

• Peace of Mind: Set your strategy and let Bender handle the rest
• 24/7 Operation: Markets never sleep, and neither does Bender
• Smart Strategies: Implements proven trading strategies while managing risks
• Transparent: Always know what's happening with your trades
• User-Friendly: Built with simplicity in mind - no complex setups needed

📈 Trading Strategy

Bender uses a carefully crafted trading strategy designed for both safety and performance:

🎯 Multi-Signal Buy Strategy

Bender uses 3 independent buy signals - if ANY signal triggers, it buys. This gives more opportunities while maintaining quality:

Signal 1: Strong Oversold (RSI < 40)

• What it means: The price has dropped significantly and is likely to bounce back
• Think of it as: A rubber band stretched down - it wants to snap back up
• Example: BOME-EUR: RSI 24.79 → Strong Oversold! ✓ BUY

Signal 2: Moderate Oversold + Momentum (RSI < 55 AND MACD > Signal)

• What it means: The price dropped somewhat AND momentum is turning positive
• Think of it as: A ball rolling downhill that's starting to slow and reverse
• Example: DOGS-EUR: RSI 38.28, MACD crossing up → Moderate + Momentum! ✓ BUY

Signal 3: Near Support + Momentum (Price < Lower BB × 1.01 AND MACD ≈ Signal)

• What it means: Price hit a support level (floor) and momentum is about to turn
• Think of it as: A basketball hitting the floor - about to bounce
• Example: FLOKI-EUR: At support, MACD crossing → Near Support! ✓ BUY

🛡️ Sell Strategy

Technical Sell Signal (RSI > 60 AND MACD < Signal)

• Price is overbought AND momentum is turning negative
• Exits before major reversals

Automatic Risk Controls

• Stop-Loss: Sells at -5% by default (configurable via STOP_LOSS_PCT)
• Take-Profit: Sells at +15% by default (configurable via TAKE_PROFIT_PCT)

🎲 Intelligent Market Selection

• Multi-factor scoring system analyzing 5 key metrics
• Bid-ask spread filtering (rejects markets with >0.5% spread)
• Volume consistency checks (detects and avoids pump & dump patterns)
• Risk-adjusted returns analysis (Sharpe & Sortino ratios)
• Volatility-focused selection to maximize trading opportunities

💼 Portfolio Management

• Multi-market trading: Runs 3 markets simultaneously by default (configurable via MAX_POSITIONS)
• Smart position sizing: €10 per position by default (configurable via TRADE_AMOUNT)
• Position tracking: Real-time P/L monitoring per position
• Automatic minimum order handling
• Complete trade history with statistics

🔄 Restart-Safe Design

• Resumes with open positions: Safely restarts without losing track of trades
• Position recovery: Automatically loads existing positions on startup
• Continuous monitoring: Checks sell conditions on all open positions

🚀 Getting Started

Prerequisites

• Python 3.8 or higher
• A Bitvavo account (Sign up here to support the project!)

Why Bitvavo?

I chose Bitvavo as our trading platform for several reasons:

• 🛡️ Strong security measures
• 💰 Low trading fees
• 🌍 Excellent European coverage
• 👥 Outstanding customer support
• ⚡ Fast and reliable API

Using my referral link above helps support Bender's development while giving you access to one of Europe's most trusted cryptocurrency platforms!

Installation

# Clone the repository
git clone https://github.com/latinvm/bender.git
cd bender

# Create and activate a virtual environment
python -m venv venv
source venv/bin/activate  # On Windows, use `venv\Scripts\activate`

# Install dependencies and the trader command
pip install -r requirements.txt
pip install -e .

# Set up your configuration
cp .env.example .env
# Edit .env with your Bitvavo API credentials

🔧 Configuration

1. Create an API key in your Bitvavo account
2. Add your credentials to the .env file:

BITVAVO_API_KEY=your_api_key
BITVAVO_API_SECRET=your_api_secret
BITVAVO_OPERATOR_ID=1 (64 bit integer)

📊 Trading Strategy Settings

All trading parameters can be customized via the .env file:

# Trading Strategy Configuration
TRADE_AMOUNT=10.0                # Amount in EUR to invest per position
STOP_LOSS_PCT=5.0                # Stop loss percentage (e.g., 5.0 = -5%)
TAKE_PROFIT_PCT=15.0             # Take profit percentage (e.g., 15.0 = +15%)
MAX_COIN_PRICE=10.0              # Maximum coin price in EUR to consider
STRATEGY_INTERVAL=60             # Seconds between strategy execution cycles
MARKET_CACHE_HOURS=6             # Hours to cache top 50 market selections
MAX_CANDIDATES=30                # Maximum markets to analyze in detail

What These Settings Mean:

• TRADE_AMOUNT: How much EUR to invest per position (default: €10)
• STOP_LOSS_PCT: Maximum loss before auto-selling (default: 5% = -5% loss)
• TAKE_PROFIT_PCT: Target profit before auto-selling (default: 15% = +15% gain)
• MAX_COIN_PRICE: Only trade coins under this price (default: €10)
• STRATEGY_INTERVAL: How often to check for trading signals in seconds (default: 60)
• MARKET_CACHE_HOURS: How long to cache market rankings (default: 6 hours)
• MAX_CANDIDATES: Number of top markets to analyze deeply (default: 30)

Example Custom Configuration:

# More aggressive settings
TRADE_AMOUNT=25.0
STOP_LOSS_PCT=3.0
TAKE_PROFIT_PCT=20.0
STRATEGY_INTERVAL=30

🎮 Usage

Virtual Trading (Paper Trading - Recommended for Testing!)

Test your strategies with virtual money using real Bitvavo market data:

# Start virtual trading (logs to console)
trader virtual

# Start virtual trading with live monitor (logs to file)
trader virtual --monitor

# Start fresh with reset wallet and live monitor
trader virtual --monitor --reset

# Show virtual trading statistics
trader virtual --stats

# Reset virtual wallet to initial balance
trader virtual --reset

Why Use Virtual Trading?

• Test strategies risk-free with simulated trades
• Uses real-time Bitvavo market data
• Separate database tracks all virtual trades
• Live terminal UI with --monitor flag
• Perfect for learning and strategy optimization

Real Trading

To run the trading bot with real money:

# Start real trading (logs to console)
trader trade

# Start real trading with live monitor (logs to file)
trader trade --monitor

# Show real trading statistics
trader trade --stats

⚠️ WARNING: This uses real money! Test with virtual trading first.

Monitor Mode

When you use the --monitor flag, Bender runs a beautiful live terminal UI:

• Real-time updates - See trades happen instantly as the bot runs
• Live positions - Watch your positions and P/L update every 5 seconds
• Trading statistics - View win rate, total trades, and performance metrics
• Logs to file - All output goes to logs/YYYY-MM-DD.log instead of console
• Interactive - Press r to refresh, q to quit

# Virtual trading with live monitor
trader virtual --monitor

# Real trading with live monitor
trader trade --monitor

Backtesting

Test strategies on historical data:

trader backtest --market VET-EUR --start 2024-01-01 --end 2024-12-31

🔧 Known Issues & Fixes

Bitvavo Rate Limit Bug (FIXED ✅)

The upstream python-bitvavo-api library has a bug that causes ValueError: sleep length must be non-negative. This has been fixed in Bender with an automatic patch.

What was the issue?

Exception in thread Thread-1:
ValueError: sleep length must be non-negative

Our solution: Bender automatically patches the library on startup to handle this gracefully. No action needed from you!

For technical details, see docs/BITVAVO_RATE_LIMIT_FIX.md

🧪 Running Tests

Bender has a comprehensive test suite. To run the tests:

# Activate the virtual environment
source venv/bin/activate  # On Windows: venv\Scripts\activate

# Install development dependencies
pip install -r requirements-dev.txt

# Run all tests
python -m pytest tests/ -v

# Run a specific test file
python -m pytest tests/test_config.py -v

# Run with coverage report
python -m pytest tests/ --cov=src/trader --cov-report=term-missing

Test Categories:

• test_config.py - Configuration loading and validation
• test_database.py - Trade database operations
• test_enhanced_strategy.py - Trading strategy logic and signals
• test_multi_market_strategy.py - Multi-market portfolio management
• test_market.py - Market operations and API interactions
• test_virtual_wallet.py - Virtual trading wallet functionality
• test_bitvavo_patch.py - Bitvavo rate limit fix verification

💡 Contributing

Contributions are welcome! Feel free to:

• Report bugs
• Suggest new features
• Submit pull requests

❤️ Support the Project

If you find Bender helpful, the best way to support its development is by:

1. Using my Bitvavo referral link when creating your account
2. Starring the project on GitHub
3. Sharing your success stories!

📝 License

This project is licensed under the MIT License - see the LICENSE file for details.

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Happy Trading with Bender! 🤖✨

Remember: Trading cryptocurrency involves risk. Always trade responsibly and never invest more than you can afford to lose.