michaelcrubin/blockchain_macadao

Sandbox for testing and developing Blockchain algorithms of common interest

MACADAO Blockchain Dev

This project is a tutorial on blockchain technology, aiming to provide a better understanding of the mechanics behind a blockchain. It demonstrates the implementation of a blockchain from scratch, showcasing the concepts of proof of work and decentralization.

Tutorial Video

Before diving into the code and details of the project, we recommend watching the following introductory video that provides an overview of blockchain technology and its fundamental concepts:

Code Overview

The provided code implements a basic blockchain and exposes an API for interacting with it. Here is a summary of the main components and functionalities:

1. Blockchain Class: This class represents the blockchain itself and contains methods for block creation, proof of work, hashing, validation, transaction management, node management, and chain replacement.

2. API Requests: The code includes several API endpoints implemented using Flask, allowing you to interact with the blockchain. Here are the available endpoints:

   • /mine_block: This endpoint triggers the mining process to create a new block. It calculates the proof of work, adds transactions, and creates a new block in the blockchain.

   • /get_chain: This endpoint retrieves the full chain of the blockchain.

   • /is_valid: This endpoint checks if the entire blockchain is valid.

   • /add_transaction: This endpoint adds a new transaction to the transaction list, which will later be included in a mined block.

   • /connect_node: This endpoint connects a new node to the blockchain network.

   • /replace_chain: This endpoint replaces the current chain with the longest chain in the network, ensuring consensus.

Getting Started

To run this project, follow these steps:

1. Make sure you have Python installed on your machine.

2. Install the necessary dependencies. You can use the following command:

   pip install flask requests
   

3. Copy the provided code into a file named blockchain.py or any other preferred filename.

4. Open a terminal or command prompt and navigate to the directory where the file is located.

5. Run the following command to start the blockchain:

   python blockchain.py
   

API Usage

Once the blockchain is running, you can use the following API endpoints to interact with it:

• To mine a new block, make a GET request to /mine_block.

• To retrieve the full chain, make a GET request to /get_chain.

• To check the validity of the blockchain, make a GET request to /is_valid.

• To add a transaction, make a POST request to /add_transaction with the following JSON payload:

  {
    "sender": "SENDER_ADDRESS",
    "receiver": "RECEIVER_ADDRESS",
    "amount": AMOUNT
  }
  

  Replace SENDER_ADDRESS, RECEIVER_ADDRESS, and AMOUNT with appropriate values.

• To connect a new node to the network, make a POST request to /connect_node with the following JSON payload:

  {
    "nodes": ["NODE1_URL", "NODE2_URL", ...]
  }
  

  Replace "NODE1_URL", "NODE2_URL", etc., with the URLs of the nodes you want to connect.

• To replace the current chain with the longest chain in the network, make a GET request to /replace_chain.

Note: Replace NODE1_URL, NODE2_URL, etc., with the actual URLs of the nodes you want to connect.

Conclusion

This project provides an educational implementation of a blockchain from scratch, emphasizing the concepts of proof of work and decentralization. By running the code and interacting with the provided API endpoints, you can gain a better understanding of how a blockchain functions. Feel free to explore and experiment with the code to enhance your understanding of blockchain technology.