Blockchain in Go

This project demonstrates a simple implementation of a blockchain using Go. It simulates a decentralized ledger for tracking books and their transactions. The blockchain stores book transactions in blocks, where each block is cryptographically linked to its predecessor.

Features

• Book Creation: Allows the creation of books and generates a unique book ID.
• Blockchain: Stores book transactions as blocks, with each block being validated.
• Genesis Block: The first block in the blockchain, used to initialize the chain.
• API Endpoints:
  • GET /: Returns the entire blockchain.
  • POST /: Adds a new block to the blockchain.
  • POST /new: Creates a new book and returns its details.

Setup

Prerequisites

• Go (version 1.18 or higher)

Installation

1. Clone the repository:

   git clone https://github.com/adammast/bookstore-blockchain-go.git
   cd bookstore-blockchain-go

2. Install dependencies (if any):

   go mod tidy

Running the Server

Run the application:

go run .

This will start a local server on http://localhost:3000.

API Example

• Create a new book:

  • POST /new with JSON payload:

    {
        "title": "The Go Programming Language",
        "author": "Alan A. A. Donovan",
        "publish_date": "2015-10-26",
        "isbn": "9780134190440"
    }

• Add a new transaction (book purchase):

  • POST / with JSON payload:

    {
        "book_id": "book_id_123",
        "user": "John Doe",
        "purchase_date": "2025-03-16",
        "is_genesis": false
    }

• Get blockchain:

  • GET / to retrieve the current blockchain.

Libraries Used

• gorilla/mux: A powerful URL router and dispatcher for Go, used to manage HTTP routes in the project.
• crypto/md5: Part of the Go standard library, used for generating MD5 hashes to create unique book IDs.
• crypto/sha256: Part of the Go standard library, used for generating SHA-256 hashes for block validation.
• encoding/json: Used for encoding and decoding JSON data, which allows communication with the API.
• encoding/hex: Used to encode and decode hexadecimal strings, specifically for generating book IDs and hash outputs.
• sync: Used for concurrency and synchronization.
• log: Used for logging messages to standard output and error output.
• net/http: Part of the Go standard library, used to create and manage the HTTP server and handle requests.
• fmt: Used for formatted I/O operations such as printing to the console.
• io: Provides basic I/O functionality, including writing and reading data to and from the HTTP response.

License

This project is licensed under the MIT License.