Wallet functionalities to create raw transaction, to sign on unsigned transaction, to send signed transaction for BTC, BCH, ETH, XRP and so on.

• Bitcoin
• Bitcoin Cash
• Ethereum
• ERC-20 Token
• Ripple

• This project is under refactoring based on Clean Code, Clean Architecture, Refactoring
  • ✅ Domain layer separated (pkg/domain/) - Pure business logic with zero infrastructure dependencies
  • ✅ Application layer (pkg/application/usecase/) - Use case implementations following Clean Architecture
  • ✅ Infrastructure layer (pkg/infrastructure/) - External dependencies (API clients, database, repositories)
  • 🔄 Migration from legacy pkg/wallet/service/ to new pkg/application/usecase/ in progress
  • ✅ Integration tests separated using build tags (//go:build integration)
• Bitcoin Core version 22.0 is released. Signet environment is ongoing.

• Pubkey addresses are given to our users first.
• Users would want to deposit coins on our system.
• After users sent coins to their given addresses, these all amount of coins are sent to our safe addresses managed offline by cold wallet

• Users would want to withdraw their coins to specific addresses.
• Transaction is created and sent after payment is requested by users.

• Internal use. Each accounts can transfer coins among internal accounts.

This is explained for BTC/BCH for now.
There are mainly 3 wallets separately and these wallets are expected to be installed in each different devices.

• Only this wallet run online to access to BTC/BCH Nodes.
• Only pubkey address is stored. Private key is NOT stored for security reason. That's why this is called watch only wallet.
• Major functionalities are
  • creating unsigned transaction
  • sending signed transaction
  • monitoring transaction status.

• Key management functionalities for accounts.
• This wallet is expected to work offline.
• Major functionalities are
  • generating seed for accounts
  • generating keys based on HD Wallet
  • generating multisig addressed according to account setting
  • exporting pubkey addresses as csv file which is imported from Watch only wallet
  • signing on unsigned transaction as first sign. However, multisig addresses could not be completed by only this wallet.

• The internal authorization operators would use this wallet to sign on unsigned transaction for multisig addresses.
• Each of operators would be given own authorization account and Sing wallet apps.
• This wallet is expected to work offline.
• Major functionalities are
  • generating seed for accounts for own auth account
  • generating keys based on HD Wallet for own auth account
  • exporting full-pubkey addresses as csv file which is imported from Keygen wallet to generate multisig address
  • signing on unsigned transaction as second or more signs for multisig addresses.

• Golang 1.25.5+
• golangci-lint 1.44.2+ (for development)
• direnv
• Docker
  • MySQL 5.7
  • Node Server
    • BTC: Bitcoin Core 0.18+ for Bitcoin node
    • BCH: Bitcoin ABC 0.21+ for Bitcoin cash node
    • ETH: go-ethereum, Ganache, erc20-token
    • XRP: rippled, ripple-lib-server

• cmd ... app directories including main.go
  • keygen ... keygen wallet
  • sign ... sign wallet
  • watch ... watch wallet
• data
  • address ... generated files by this CLI
  • certs ... for docker volume directory used by docker-compose.xrp.yml
  • config ... config toml files
  • contract ... generated token abi file
  • dump ... BTC wallet file generated by api dumpwallet command. See Makefile.
  • fullpubkey ... generated files by this CLI
  • gaiad ... genesis.json for cosmos gaiad
  • keystore ... keystore for Ethereum
  • proto ... proto files for ripple gRPC communication
• docker ... docker resources
• docs ... documents
• images ... for only docs
• pkg ... go files
• scripts ... shell scripts
• web
  • erc20-token ... erc20 token contract
  • ripple-lib-server ... Ripple gRPC server

The project follows Clean Architecture principles with clear layer separation:

Pure business logic with zero infrastructure dependencies:

• domain/account/ ... Account types, validators, and business rules
• domain/transaction/ ... Transaction types, state machine, validators
• domain/wallet/ ... Wallet types and definitions
• domain/key/ ... Key value objects and validators
• domain/multisig/ ... Multisig validators and business rules
• domain/coin/ ... Cryptocurrency type definitions

Use case layer following Clean Architecture:

• application/usecase/keygen/ ... Key generation use cases (btc, eth, xrp, shared)
• application/usecase/sign/ ... Signing use cases (btc, eth, xrp, shared)
• application/usecase/watch/ ... Watch wallet use cases (btc, eth, xrp, shared)

External dependencies and implementations:

• infrastructure/api/bitcoin/ ... Bitcoin/BCH Core RPC API clients. API References
• infrastructure/api/ethereum/ ... Ethereum JSON-RPC API clients. API References
• infrastructure/api/ripple/ ... Ripple gRPC API clients to communicate with ripple-lib-server
• infrastructure/database/ ... Database connections and generated code (MySQL, sqlc)
• infrastructure/repository/ ... Data persistence implementations (cold wallet, watch wallet)
• infrastructure/storage/ ... File storage implementations (address, transaction)
• infrastructure/network/ ... Network communication (WebSocket, gRPC)

• wallet/service/ ... Legacy business logic orchestration (being migrated to application/usecase/)
• wallet/key/ ... Key generation logic (HD wallet, seeds)
• wallet/wallets/ ... Wallet implementations (btcwallet, ethwallet, xrpwallet)

• command/ ... Command implementations (keygen, sign, watch)
• config/ ... Configuration management
• logger/ ... Logging utilities
• di/ ... Dependency injection container
• address/ ... Address formatting and utilities
• account/ ... Account-related utilities (backward compatibility type aliases)
• contract/ ... Smart contract utilities (ERC-20 token ABI)
• converter/ ... Data conversion utilities
• testutil/ ... Test utilities

• ripple-lib-server
  • ./web/ripple-lib-server
• erc20-token
  • ./web/erc20-token

Installation

• For Bitcoin
• operation scripts

• Makefile - Main Makefile with modular includes
• Makefile modules (in make/ directory):
  • watch_op.mk - Watch wallet operations
  • keygen_op.mk - Keygen wallet operations
  • sign_op.mk - Sign wallet operations
  • And other specialized modules for builds, tests, Docker, etc.

• Remove github.com/cpacia/bchutil due to outdated code. Try to replace to github.com/gcash/bchd
• Separate dependent test as Integration Test using tag (//go:build integration)
• Complete migration from pkg/wallet/service/ to pkg/application/usecase/
• Add ATOM tokens on Cosmos Hub
• Add Polkadot
• Various monitoring patterns to detect suspicious operations.
• Add Github Action as CI
• Generate mnemonic instead of seed. bip-0039

• Setup Signet environment for development use
• Fix overpaying fee issue on Signet. It says 725% overpaying.
• native SegWit-Bech32
• Multisig-address is used only once because of security reason, so after tx is sent, related receiver addresses should be updated by is_allocated=true.
• Sent tx is not proceeded in bitcoin network if fee is not enough comparatively. So re-sending tx functionality is required adding more fee.

• Add any useful APIs using contract equivalent to ETH APIs
• Monitoring for ERC20 token

• Make sure that quantity-tag is used properly. e.g. when getting balance, which quantity-tag should be used, latest or pending.
• Handling secret of private key properly. Password could be passed from command line argument.

• Handling secret of private key properly. Password could be passed from command line argument.

This project follows Clean Architecture principles with clear layer separation:

Application Layer (application/usecase, wallet/service, command)
    ↓ depends on
Domain Layer (domain/*)
    ↑ implements interfaces defined by
Infrastructure Layer (infrastructure/*, wallet/key)

• Domain Layer: Pure business logic with zero infrastructure dependencies
• Application Layer: Use cases orchestrate business logic by coordinating domain objects and infrastructure services
• Infrastructure Layer: Implements interfaces defined by domain layer (Dependency Inversion Principle)
• Dependency Direction: Outer layers depend on inner layers, never the reverse

For detailed architecture guidelines, see AGENTS.md.

• The pkg layout pattern, refer to the linked URLs for details.