Wise Currency Converter Server

A Model Context Protocol (MCP) server that provides currency conversion using the Wise API.

Prerequisites

You need a Wise API key to use this server. Get your API key from Wise API.

Features

• Convert Currency: Convert amounts between different currencies using real-time or historical Wise exchange rates
• List Currencies: Get a list of all supported currency codes
• Rate Caching: Built-in caching to minimize API calls
• Cross-rate Calculation: Automatic fallback to USD-based cross-rate calculation when direct rates are unavailable

Installation

npm install
npm run build

Configuration

API Key Setup

Set your Wise API key as an environment variable:

export WISE_API_KEY="your-api-key-here"

Or copy the example environment file and add your key:

cp .env.example .env
# Edit .env and add your API key

Security Note: Never commit your API key to version control. The .gitignore file is configured to exclude .env files.

Usage

As an MCP Server

The server runs on stdio and can be used with any MCP client:

node dist/index.js

Available Tools

1. convert_currency

Converts an amount from one currency to another.

Parameters:

• source_currency (string, required): Source currency code (e.g., USD, EUR, GBP)
• amount (number, required): Amount to convert
• target_currency (string, required): Target currency code
• date (string, optional): Date for historical rate in YYYY-MM-DD format

Example Response:

{
  "source_currency": "USD",
  "source_amount": 100,
  "target_currency": "EUR",
  "target_amount": 92.45,
  "exchange_rate": 0.9245,
  "date": "2024-01-15"
}

2. list_currencies

Returns a list of all supported currency codes.

Example Response:

{
  "currencies": ["USD", "EUR", "GBP", "JPY", ...],
  "total": 40
}

Configuration with Claude Desktop

To use this MCP server with Claude Desktop, add it to your config file:

macOS

Edit ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "wise-currency": {
      "command": "node",
      "args": ["/path/to/wise-currency-converter-mcp/dist/index.js"],
      "env": {
        "WISE_API_KEY": "your-api-key-here"
      }
    }
  }
}

Windows

Edit %APPDATA%\Claude\claude_desktop_config.json:

{
  "mcpServers": {
    "wise-currency": {
      "command": "node",
      "args": ["C:\\path\\to\\wise-currency-converter-mcp\\dist\\index.js"],
      "env": {
        "WISE_API_KEY": "your-api-key-here"
      }
    }
  }
}

Supported Currencies

The server supports 40 major world currencies including:

• USD, EUR, GBP, JPY, AUD, CAD, CHF, CNY, SEK, NZD
• MXN, SGD, HKD, NOK, KRW, TRY, RUB, INR, BRL, ZAR
• And 20 more...

Testing

Test the server functionality:

# Run the test script
WISE_API_KEY="your-api-key" node test.js

Development

# Install dependencies
npm install

# Build the project
npm run build

# Watch for changes during development
npm run dev

# Run the server directly for testing
WISE_API_KEY="your-api-key" node dist/index.js

Project Structure

wise-currency-converter-mcp/
├── src/
│   ├── index.ts         # MCP server implementation
│   ├── wise-client.ts   # Wise API client with caching
│   └── types.ts         # TypeScript type definitions
├── dist/                # Compiled JavaScript output
├── test.js             # Test script for validation
├── .env.example        # Example environment configuration
├── .gitignore          # Git ignore rules
├── package.json        # Node.js dependencies
└── tsconfig.json       # TypeScript configuration

Architecture

• TypeScript: Full type safety and better IDE support
• MCP SDK: Official Model Context Protocol SDK for server implementation
• Wise API: Real-time and historical exchange rates
• Caching: 1-minute TTL cache to reduce API calls
• Error Handling: Graceful fallback to cross-rate calculation
• Security: API key stored in environment variables, sanitized error logging

Troubleshooting

API Key Issues

• Ensure your API key is correctly set in the environment
• Check that the API key has the necessary permissions for rate queries
• The server will warn if no API key is detected

Connection Issues

• Verify the Wise API endpoint is accessible
• Check network connectivity
• Review error messages in the console output

License

MIT