MCP Currency Converter

A Model Context Protocol (MCP) server that

Installation

# Using npm
npm install @yansirplus/mcp-wp

# Using yarn
yarn add @yansirplus/mcp-wp

# Using bun
bun install @yansirplus/mcp-wp

Using as a CLI Tool

After installation, you can run the MCP server directly from the command line:

# If installed globally
mcp-wp

# If installed locally
npx @yansirplus/mcp-wp

This will start the MCP server in stdio mode, allowing you to connect to it with MCP clients.

Using as a dependency

// Import the server
import { server } from "@yansirplus/mcp-wp";

// Connect to your own transport
import { YourTransport } from "./your-transport.js";
const transport = new YourTransport();
await server.connect(transport);

// Or use programmatically
const toolResponse = await server.callTool("usd-to-cny", { amount: 100 });
console.log(toolResponse);

// Just use the conversion function
import { convertUsdToCny } from "@yansirplus/mcp-wp";
console.log(convertUsdToCny(100)); // 730

Building

bun run build

Running

Stdio Mode (Command Line)

bun start

HTTP Server Mode

This mode exposes the MCP server over HTTP with Server-Sent Events (SSE):

bun run start:http

The server will run on port 3000 by default. You can set a different port using the PORT environment variable:

PORT=8080 bun run start:http

Endpoints:

• SSE Connection: GET /sse
• Message Endpoint: POST /messages?sessionId=<your-session-id>

Usage

This MCP server provides a single tool:

usd-to-cny

Converts a USD amount to CNY using a fixed exchange rate of 7.3.

Parameters:

• amount: A positive number representing the USD amount to convert

Example Response:

100 USD = 730.00 CNY (rate: 7.3)

Testing with MCP Inspector

You can test this server using the MCP Inspector. Run the server and then connect the inspector to it.

Testing Stdio Mode

1. Start the server: bun start
2. Open the MCP Inspector
3. Select the server type (localhost stdio)
4. Connect to the server
5. Use the "Call Tool" tab to test the usd-to-cny tool

Testing HTTP Mode

1. Start the HTTP server: bun run start:http
2. Open the MCP Inspector
3. Select the server type (HTTP with SSE)
4. Set the SSE URL to http://localhost:3000/sse
5. Set the Message URL to http://localhost:3000/messages
6. Connect to the server
7. Use the "Call Tool" tab to test the usd-to-cny tool

License

MIT