🪙 Blocksmith — Minimal Rust Blockchain Node

Blocksmith is a lightweight, educational blockchain node written in Rust, designed to demonstrate:

Basic blockchain implementation;
Proof-of-Work (PoW) mining;
Peer-to-Peer (P2P) networking using libp2p;
An async API service for transaction submission.

⚙️ Architecture Overview

Each node consists of several asynchronous modules running concurrently.

| Module | Description | |:-----------------:|:-----------------------------------------------------------------------------------------------------------------------| | Mining | Computes PoW for the next block in a background thread. Automatically stops when a valid block is received from peers. | | P2P Node | Handles peer discovery, connection establishment/closing, message propagation, and block/transaction broadcast. | | API Service | Provides HTTP endpoint to submit transactions. | | Input Service | Provides ability to query the blockchain state using CLI. | | App State | Shared mutable state protected by Arc<Mutex<_>> for safe concurrent access. |

All modules coordinate through Tokio channels and a shared AppState structure.

🚀 Features

✅ Proof-of-Work (PoW) mining
✅ Libp2p peer discovery and gossiping
✅ Transaction and block propagation
✅ Modular async design (Tokio tasks + blocking miners)
✅ JSON and efficient bincode serialization

🧠 How Mining Works

Each node mines new blocks using simplified PoW algorithm which generates approximately 100000 hashes per second. When another node broadcasts a valid block, the current miner stops mining its own block and moves on to the next one. The same happens when the current miner mines a new block - it broadcasts it and all other miners stop with current mining process and move on to the next block mining.

🛠️ Running Locally

Prerequisites

Rust (>= 1.8)
Cargo
libclang (for libp2p)

Install dependencies

cargo build

Run a single node

cargo run | bunyan

Nodes automatically connect via libp2p::Swarm.

⚙️ Configuration

It is possible to skip mining of the genesis block in all nodes which are launched after the very first one by setting up MINE_GENESIS environmental variable to false either in the .env file or as global environmental variable.

In addition, mining difficulty may be configured by setting up the DIFFICULTY_PREFIX environmental variable. Default value is "000". It is planned to implement changeable mining difficulty algorithm in the future to avoid manual configuration of this value.

It is also possible to configure API service host and port by modifying them in the configuration.yaml file.

🧰 Tech Stack

Rust + Tokio — concurrency runtime
libp2p — Peer-to-Peer networking
sha2 — hashing
serde + bincode — serialization
actix-web — API server
tracing — telemetry and structured logging

💬 Future Improvements

✅ Implement changeable mining difficulty algorithm
✅ Replace Proof-of-Work (PoW) algorithm with Proof-of-Stake (PoS) algorithm
✅ Add persistent storage (LevelDB or RocksDB)
✅ Implement peer reputation and bootstrapping for faster peers discovering
✅ Implement enhanced block/transaction/chain validation
✅ Add WebSocket real-time event stream
✅ Implement block size limit
✅ Implement cryptocurrency minting, tokenomics and add mining rewards

Blocksmith

Install / Use

README