Kaidos is a lightweight, educational blockchain and cryptocurrency implementation written in Python. It features a complete UTXO transaction model (similar to Bitcoin), proof-of-work mining, wallet management, and peer-to-peer networking capabilities. This project serves as both a learning resource for blockchain technology and a functional cryptocurrency system.
- Complete UTXO System: Implements the Unspent Transaction Output model used by Bitcoin for secure coin tracking
- Proof-of-Work Mining: Includes mining functionality with difficulty adjustment and block rewards
- Halving Mechanism: Block rewards that halve every 210,000 blocks, similar to Bitcoin's economic model
- Transaction Fees: Miners receive transaction fees as incentives for including transactions in blocks
- Secure Wallet Management: Tools to create and manage cryptographic keys and addresses
- Multi-Signature Support: Create addresses requiring multiple signatures for enhanced security
- Merkle Tree Verification: Efficient transaction verification using cryptographic Merkle trees
- P2P Networking: Decentralized node communication for transaction and block propagation
- Consensus Algorithm: Implements chain selection based on proof-of-work and chain length
- Command-Line Interface: Simple CLI tools for all blockchain operations
# Grab the code
git clone https://github.com/jolovicdev/kaidos.git
cd kaidos
# Set up a virtual environment
python -m venv venv
source venv/bin/activate # On Windows: venv\Scripts\activate
# Install it in dev mode so you can tinker
pip install -e .# Make yourself a wallet
kaidos-wallet create
# See what wallets you've got
kaidos-wallet list
# Check your balance
kaidos-wallet balance <address>
# Need a new address? No problem
kaidos-wallet address <wallet_id>
# See all your addresses
kaidos-wallet addresses <wallet_id>
# Send some coins!
kaidos-wallet tx <sender> <recipient> <amount>
# Or save the transaction for later
kaidos-wallet tx <sender> <recipient> <amount> --output transaction.json
# Check your unspent coins
kaidos-wallet utxos <address># Set up your node first
kaidos-node init
# Fire it up!
kaidos-node start --host <host> --port <port>
# Do some mining (and earn some coins)
kaidos-node mine <miner_address>
# Check out the blockchain
kaidos-node blocks
# Send that transaction you saved earlier
kaidos-node send transaction.json
# Sync with other nodes
kaidos-node consensus
# Got friends? Add their nodes
kaidos-node add-peer <peer_address>
# See who you're connected to
kaidos-node list-peers
# What transactions are waiting to be mined?
kaidos-node transactions
# Check specific address balances
kaidos-node utxos <address>Check out COMMANDS.md for all the cool things you can do.
Want to send someone some Kaidos coins? It's pretty simple:
-
Create your transaction:
kaidos-wallet tx <your_address> <their_address> <amount> --output transaction.json
-
Send it to the network:
kaidos-node send transaction.json
- Blocks: Containers for batches of transactions with cryptographic links to previous blocks
- Blockchain: The complete history of all blocks linked in a secure chain
- Transaction Manager: Handles the UTXO set, transaction validation, and mempool management
- Wallet: Manages cryptographic keys, addresses, and transaction signing
- Node: Provides network communication and consensus mechanisms
The Unspent Transaction Output (UTXO) model is a fundamental concept in Kaidos:
- Coins exist as "unspent outputs" from previous transactions
- When spending coins, these outputs are consumed as inputs for new transactions
- Change from transactions is returned as a new UTXO to the sender
- Transaction fees (the difference between inputs and outputs) are collected by miners
- Block Rewards: Miners receive 50 coins initially for each new block
- Halving Schedule: Rewards halve every 210,000 blocks (25, 12.5, 6.25, etc.)
- Difficulty Adjustment: Mining difficulty adjusts based on block generation time
- Proof-of-Work: Miners must find a block hash with a specific number of leading zeros
- Chain Selection: The longest valid chain with the most cumulative work is considered canonical
If you want to run the tests:
# Run everything
pytest
# Just test the blockchain parts
pytest Kaidos/tests/test_blockchain.py
# See all the details
pytest -v
# Check how much of the code is covered
pytest --cov=KaidosKaidos/
├── cli/ # The command line tools
│ ├── node_cli.py # For node commands
│ └── wallet_cli.py # For wallet commands
├── core/ # The heart of it all
│ ├── block.py # Block structure
│ ├── blockchain.py # Chain management
│ ├── exceptions.py # Custom errors
│ ├── merkle_tree.py # Merkle tree implementation
│ └── transaction_manager.py # Handles transactions and UTXOs
├── network/ # P2P networking
│ └── node.py # Node implementation
├── wallet/ # Wallet functionality
│ ├── wallet.py # Manages keys and addresses
│ └── multisig.py # Multi-signature wallet support
└── tests/ # Making sure it all works
├── test_blockchain.py # Tests for blockchain
├── test_consensus.py # Tests for consensus
├── test_merkle_tree.py # Tests for Merkle tree
├── test_multisig.py # Tests for multi-signature
├── test_network.py # Tests for networking
├── test_transaction_manager.py # Tests for transactions
└── test_wallet.py # Tests for wallet
Kaidos uses ZenithDB (a SQLite wrapper) for persistent storage of:
- Blockchain Data: All blocks and their transactions
- UTXO Set: The current set of unspent transaction outputs
- Mempool: Pending transactions waiting to be mined
- Wallet Information: Encrypted keys and address data
- Network Data: Peer connection information and node configuration
This project is licensed under the MIT License - see the LICENSE file for details.