MCP Money

An MCP (Model Context Protocol) money implementation for Nostr using NDK (Nostr Development Kit) with Cashu ecash functionality.

Features

• Cashu Wallet Integration: Full support for Cashu ecash mints and tokens
• Lightning Network: Deposit via Lightning invoices and pay Lightning invoices
• Nostr Zaps: Send zaps to users using npub or NIP-05 identifiers
• Multi-mint Support: Manage multiple Cashu mints simultaneously
• Persistent Storage: Wallet state saved to local file with mint info caching
• MCP Server: Expose wallet functionality through Model Context Protocol
• CLI Interface: Direct command-line usage for all wallet operations

Installation

npm install mcp-money

Usage

MCP Server Mode (Default)

Run without arguments to start the MCP server:

npx mcp-money

CLI Mode

Use specific commands for direct wallet operations:

# Get total balance
npx mcp-money get_balance

# Get balance per mint
npx mcp-money get_mint_balances

# Create deposit invoice
npx mcp-money deposit 1000 https://testnut.cashu.space

# Pay lightning invoice
npx mcp-money pay lnbc1...

# Send a zap
npx mcp-money zap npub1... 100 "Great post!"

# Add a new mint
npx mcp-money add_mint https://mint.example.com

Authentication

The wallet supports multiple ways to provide your Nostr private key:

1. Command line: --nsec nsec1...
2. Environment variable: NSEC=nsec1...
3. Config file: Automatically saved to .wallet.json
4. Auto-generate: Creates new key if none provided

MCP Tools

When running as an MCP server, the following tools are available:

• get_balance: Get the total wallet balance
• get_mint_balances: Get balance breakdown per mint
• deposit: Create a deposit invoice for specified amount and mint
• pay: Pay a Lightning invoice
• zap: Send a zap to a user
• add_mint: Add a mint to the wallet

Integration with AI Assistants

Claude Code Integration

To use this wallet with Claude Code, add it to your project's MCP configuration:

{
  "mcpServers": {
    "mcp-money": {
      "command": "npx",
      "args": ["mcp-money"]
    }
  }
}

Or install globally and reference the binary directly:

npm install -g mcp-money

{
  "mcpServers": {
    "mcp-money": {
      "command": "mcp-money"
    }
  }
}

Goose Integration

To use this wallet with Goose, add it to your ~/.config/goose/config.yaml:

If you have an nsec you want to use, you can set it by passing it as --nsec nsec1....

extensions:
  money:
    args:
    - -y
    - mcp-money
    bundled: null
    cmd: npx
    description: Money for agents
    enabled: true
    env_keys: []
    envs: {}
    name: money
    timeout: 300
    type: stdio

After adding the configuration, restart your AI assistant to begin using the wallet tools.

Configuration

The wallet automatically creates a .wallet.json file to store:

• Private key (nsec)
• Public key (npub)
• Configured relays
• Configured mints
• Cached mint information

Architecture

Built on top of:

• NDK: Nostr Development Kit for Nostr protocol interactions
• NDK Wallet: Cashu wallet implementation
• Nostr Tools: Low-level Nostr utilities
• Bun: Fast JavaScript runtime and package manager

Security

• Private keys are stored locally in .wallet.json
• Mint information is cached for performance
• All Nostr communications use standard NIP protocols
• Lightning payments require explicit confirmation

License

MIT

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

Support

For issues and questions, please open an issue on the GitHub repository.