Welcome to Minichain

Building a Blockchain from Scratch

Welcome to Minichain — a hands-on guide to building a minimal but complete blockchain implementation in Rust.

What You’ll Build

By the end of this book, you’ll have built:

Core Primitives

Cryptographic hashing, digital signatures, addresses, transactions, and blocks

Storage Layer

Persistent storage for accounts, blocks, and contract state using sled

Virtual Machine

A register-based VM with 16 registers, gas metering, and execution tracing

Assembler

A custom assembly language that compiles to VM bytecode

Consensus

Proof of Authority (PoA) consensus for block validation

CLI

A complete command-line interface to interact with your blockchain

Why Build a Blockchain?

Building a blockchain from scratch teaches you:

• Cryptographic fundamentals — hashing, signing, verification
• Data structures — merkle trees, state tries
• Virtual machine design — opcodes, gas, execution
• Systems programming — persistence, serialization, performance
• Distributed systems concepts — consensus, state machines

Prerequisites

This book assumes familiarity with:

• Rust programming (ownership, traits, error handling)
• Basic command-line usage
• Git version control

Project Structure

minichain/
├── crates/
│   ├── core/        # Blockchain primitives
│   ├── vm/          # Virtual machine
│   ├── storage/     # Persistent state
│   ├── consensus/   # PoA logic
│   ├── chain/       # Blockchain orchestration
│   ├── assembler/   # Assembly compiler
│   └── cli/         # Command-line interface
├── contracts/       # Example contracts
└── tests/           # Integration tests

Let’s Begin!

Ready to dive in? Start with the Project Overview to understand the architecture, then jump into Chapter 1: Core Primitives.

You can also explore the full contract example at English Auction Smart Contract.