Blockchain Project

This project is an implementation of blockchain and it's concepts in Python & Flask with Postman used for API development

Getting Started

1. Download Anaconda
2. Download Visual Studio Code
3. Download Postman
4. Clone the directory and open it in vs code
5. In terminal, enter activate to activate the base environment of Anaconda

Install the below dependencies to avoid any errors incase they're not already installed

6. Install Flask

pip install flask

7. Install Flask-Cors

pip install -U flask-cors

8. Install requests Lib

pip install requests

9. Install pycrypto (collection of hash functions)

pip install pycrypto

10. In the terminal, run the following command

python node.py

or to run multiple nodes, in a new terminal

python node.py -p<port_number>

11. Open Postman Client, Test the below API Calls

API Calls

Below is a list of API calls and short description about what they do, these api calls can conveniently be executed in Postman Localhost & Port have been set in node.py file, by default I've set them as 0.0.0.0 with port=5000

Blockchain

Creates a blockchain.txt file that contains information regarding the transactions and other information related to the blockchain

• [POST] Mine a Block:

localhost:5000/mine

• [GET] Get snapshot of current blockchain:

localhost:5000/chain

Transaction

• [POST] Add a New Transaction:

localhost:5000/transaction

Before executing the above api call, in Postman, Go to "Body" > "Raw" > Select "Json" in the current window and enter the following data:

eg. { "recipient": "NameofRecipient", "amount": 5 }

• [GET] Get a List of all Open Transactions:

localhost:5000/transactions

Wallet

creates a wallet.txt file with your port number that contains information regarding your wallet such as public key, private key

• [POST] Generate Wallet:

localhost:5000/wallet

• [GET] Fetch Wallet:

localhost:5000/wallet

• [GET] Fetch Wallet Balance:

localhost:5000/balance

Node/Server

You can run multiple nodes and test communication between the two by opening two terminals inside vs code and executing the python node.py file with arguments -p 5001 or --port 5001. So, it will look like python node.py -port 5001

You can create as many nodes/servers you want by using the open ports and appending them to the python node.py --port <port_number> command

• [POST] Add Peer Node to Your Chain Network:

localhost:5000/node

Before executing the above api call, in Postman, Go to "Body" > "Raw" > Select "Json" in the current window and enter the following data:

e.g. { "node": "localhost:5001" }

• [DELETE] Delete Peer Node:

e.g. localhost:5000/node/localhost:5001

• [GET] Get all the Nodes in your Network:

localhost:5000/nodes

File Contents

• block.py - represents single block of our blockchain

• blockchain.py - represents the blockchain

• node.py - contains all the routes for API calls

• node_console.py - provides a user interface using while loop to interact with blockchain from within the vs code terminal

• transaction.py - represents open transactions

• wallet.py - Implements functionality to generate wallet, public & private key and other security related algorithm

• API_calls_screenshot Folder - contains screenshots of successful API calls and their output

• Utility > hash_util.py - Implements functionality to hash a block

• Utility > printable.py - Converts binary data to string for printing in console

• Utility > verification.py - Implements proof of work and verification of chain and transactions

• Legacy_blockchain_files - contains old files related to project

Shoutout

Huge credits to Dapp university & howCode for explaining the concepts and how to implement them in python.

1. Dapp University Video Link
2. howCode Video Link