What is MCP?

Model Context Protocol (MCP) is an open standard created by Anthropic for connecting AI assistants to external tools and data sources. An MCP server exposes a set of typed tools that clients like Claude Code, Cursor, and Claude Desktop can call on your behalf whenever the model needs live data.

The Exchange Rate API MCP server is a lightweight bridge that gives your AI assistant direct access to real-time mid-market exchange rates and historical currency data. Once configured, your assistant can answer questions like:

"What's the current USD to EUR rate?"
"Show me GBP/JPY over the last 30 days."
"Convert 250 USD to CAD using a real rate."
"List every supported currency."

Package: @allratestoday/mcp-server on npm. Source: github.com/Exchange-RateAPI/mcp-server.

Tools Exposed

The MCP server exposes four tools that your AI assistant can call automatically:

get_exchange_rate

Get the live mid-market rate for any currency pair. Returns the current exchange rate between two currencies.

No API key needed

get_historical_rates

Get historical exchange rates with flexible periods — 1d, 7d, 30d, or 1y of data points.

API key required

get_rates_authenticated

Get rates for multiple target currencies at once with higher rate limits. Ideal for batch conversions.

API key required

list_currencies

List all 160+ supported currencies with their codes, names, and symbols.

No API key needed

Installation

Choose your AI client below. The MCP server runs via npx — no global install required.

Claude Code

Run this in your terminal:

claude mcp add exchange-rates -- npx -y @allratestoday/mcp-server

# Optional: set API key for authenticated endpoints
claude mcp env exchange-rates ALLRATESTODAY_API_KEY=your_api_key_here

Cursor

Add to .cursor/mcp.json in your project (or ~/.cursor/mcp.json globally):

{
  "mcpServers": {
    "exchange-rates": {
      "command": "npx",
      "args": ["-y", "@allratestoday/mcp-server"],
      "env": {
        "ALLRATESTODAY_API_KEY": "your_api_key_here"
      }
    }
  }
}

Claude Desktop

Edit your Claude Desktop config file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "exchange-rates": {
      "command": "npx",
      "args": ["-y", "@allratestoday/mcp-server"],
      "env": {
        "ALLRATESTODAY_API_KEY": "your_api_key_here"
      }
    }
  }
}

Restart Claude Desktop after editing.

Environment Variables

Variable	Required	Purpose
`ALLRATESTODAY_API_KEY`	Optional	Your API key. Required only for `get_historical_rates` and `get_rates_authenticated`. The other two tools work without a key.

Get a free API key at exchange-rateapi.com/register. The free plan covers personal and development use.

FAQ

Is the MCP server free?

The MCP server itself is open-source (MIT licensed). The underlying Exchange Rate API has a free tier and paid plans. Two tools (get_exchange_rate and list_currencies) work without any API key.

Does it work offline?

No — the tools call the Exchange Rate API over HTTPS to fetch live data. You can cache results locally if you need offline access.

Which AI clients are supported?

Any MCP-compatible client works. We provide setup instructions for Claude Code, Cursor, and Claude Desktop, but any client that supports the Model Context Protocol standard can connect.

Can I contribute?

Yes. The source is on GitHub — issues and pull requests are welcome.

Exchange Rate API MCP Server