This content originally appeared on DEV Community and was authored by μ΄κ΄νΈ(Gwanho LEE)
Building a Bitcoin CLI Wallet in Rust
Overview
This project is a Rust-based Bitcoin CLI wallet, built from the ground up to showcase real-world system programming, blockchain protocol mastery, and security-conscious software engineering. It serves both as a personal learning milestone and a portfolio-quality demonstration of professional development skills.
Architecture at a Glance
This wallet mirrors the internal structure of modern cryptocurrency clients, providing robust cryptographic handling, efficient network communication, and cross-platform data persistence.
Cryptography & Key Management
β’ BIP39/BIP44 HD Wallets for deterministic key generation
β’ secp256k1 curve for signing transactions (ECDSA)
β’ WIF (Wallet Import Format) support for key portability
β’ Mnemonic-based recovery system with HMAC-SHA256-derived seed
Blockchain Features
β’ UTXO Tracking: Query and track spendable outputs
β’ Transaction Creation: Construct valid Bitcoin transactions from UTXOs
β’ Blockstream API Integration (Testnet): Real-time blockchain data
β’ Gap Limit Handling: Ensures proper address discovery
Storage & Persistence
β’ JSON File Storage for cross-platform wallet state
β’ Atomic I/O operations to prevent data loss
β’ Full Backup/Recovery support via mnemonic phrase
Core Features
β’ 
BIP44-compliant HD address generation
β’ Intelligent UTXO selection
β’ Transaction signing and broadcasting
β’ Real-time wallet balance & transaction sync
β’ Cross-platform support: Linux, macOS, Windows
Security Highlights
β’ Rust guarantees memory safety and avoids common C/C++ vulnerabilities
β’ Private key isolation and zero-copy signing
β’ TLS-encrypted API communication
β’ Multi-stage transaction validation
Tech Stack
β’ Rust 1.70+ (async/await enabled)
β’ bitcoin, bitcoin_hashes, secp256k1 crates
β’ serde + serde_json for state handling
β’ reqwest for HTTP requests
β’ tokio async runtime
β’ cargo test suite for unit/integration testing
Performance
β’ 
Memory: <10MB for 1000+ wallet addresses
β’ 
Transaction Signing: <100ms
β’ 
Sync Time: <2s per request to Blockstream API
β’ Startup Time: <500ms
What I Learned
This project strengthened both foundational and advanced skills in:
Systems Programming (Rust)
β’ Ownership, borrowing, lifetimes
β’ Concurrency with async/.await
β’ Custom error types and Result handling
β’ Low-level data manipulation and optimization
Blockchain Internals
β’ Bitcoin transaction formats and script validation
β’ ECDSA cryptography, hashing algorithms (SHA256, RIPEMD160)
β’ UTXO models, fee estimation, input/output control
β’ Wallet design principles and address gap management
Software Engineering
β’ Modular architecture with clear separation of concerns
β’ Full documentation with doc comments & examples
β’ TDD approach with edge case coverage
β’ CI-ready coding practices
GitHub Repository
View the complete project and code:
https://github.com/leepl37/rust_cli_wallet
βΈ»
What Comes Next
I plan to evolve this project into a full-featured production wallet:
Security Enhancements
β’ HSM (Ledger/Trezor) support
β’ AES-GCM encryption for local files
β’ Multi-sig transaction support
Extended Functionality
β’ REST API and GraphQL integration
β’ Lightning Network support
Developer Experience
β’ Interactive REPL CLI with autocomplete
β’ Property-based testing (e.g. QuickCheck)
β’ Docker-based deployment pipeline
Performance & DevOps
β’ Redis caching for UTXO data
β’ PostgreSQL-based transaction ledger
β’ Prometheus metrics & Grafana dashboards
Letβs build the decentralized future β safely, securely, and in Rust.
Explore the code on GitHub: https://github.com/leepl37/rust_cli_wallet
This content originally appeared on DEV Community and was authored by μ΄κ΄νΈ(Gwanho LEE)