DeFi Chain: Complete Rust Project 🚀

A complete, modular Rust project for building blockchain and DeFi primitives in a single workspace.

This project includes:

• ⛓️ A proof-of-work blockchain engine
• 👛 Wallet key generation and address derivation
• 📥 A fee-prioritized mempool
• 💱 DeFi modules (AMM, lending, staking)
• 🌐 Peer networking layer
• 💾 Persistent storage wrapper
• 🛠️ RPC/CLI crate with a runnable node binary

Workspace Layout 📦

• blockchain/ - block, chain, and mining logic
• wallet/ - keypair generation, address derivation, transaction type
• mempool/ - pending transaction pool with fee ordering and TTL pruning
• defi/amm/ - constant-product AMM simulation
• defi/lending/ - collateralized borrowing simulation
• defi/staking/ - token locking and reward computation
• network/ - basic peer registry and message broadcasting/gossip behavior
• storage/ - sled-based key-value storage wrapper
• rpc/ - request/response types, CLI config, and executable entrypoint (defi-chain)

Requirements ✅

• Rust (stable)
• Cargo

Install Rust from: https://rustup.rs

Build 🔧

cargo build

Test 🧪

cargo test

Current status: tests pass in this workspace (one AMM unit test).

Run the Node CLI ▶️

The binary is defined in rpc/src/main.rs and named defi-chain.

cargo run -p rpc -- --port 3000 --difficulty 2

With an initial peer:

cargo run -p rpc -- --port 3000 --difficulty 3 --peer 127.0.0.1:4001

CLI Options

• --port <u16> (default: 3000)
• --difficulty <usize> (default: 2)
• --peer <string> (optional)

Module Highlights 🧱

Blockchain ⛏️

• Block includes index, timestamp, previous hash, nonce, data, and hash
• mine increments nonce until hash has difficulty leading zeroes
• Chain::new creates and mines a genesis block
• Chain::add_block mines and appends a new block

Wallet 🔐

• Uses k256 for ECDSA key generation
• Derives addresses by Keccak-256 hashing compressed pubkey bytes and taking the last 20 bytes (0x-prefixed)
• Includes a Transaction struct with signing payload bytes helper

Mempool 📬

• Stores txs grouped by fee in a BTreeMap
• pop_batch(n) returns highest-fee txs first
• prune_expired(now) removes old txs based on TTL

DeFi 💸

• AMM: constant product style swap with 0.3% fee approximation
• Lending: collateral tracking, borrow limit (75%), health factor, liquidation path
• Staking: lock positions and compute block-based rewards

Network 📡

• Tracks known peers
• Broadcasts messages to all peers
• Simulates gossip rebroadcast to peers except sender

Storage 🗃️

• Wraps sled with open, save, and load

Quick Code Example 👇

use blockchain::chain::Chain;

fn main() {
    let mut chain = Chain::new(2);
    chain.add_block("first block".to_string());
    println!("Tip hash: {}", chain.tip().hash);
}

Project Overview 🏁

DeFi Chain is structured as a complete Rust workspace with dedicated crates for chain execution, wallet logic, mempool processing, DeFi protocols, networking, storage, and RPC/CLI interaction.

License 📄

Add a LICENSE file to define project licensing.