Realtime Exchange Rate MCP Server

🚀 Realtime Exchange Rate MCP Server

Give your AI coding assistant a live window into the foreign-exchange market.

A Model Context Protocol server that enables Claude Code, Cursor, Claude Desktop, Windsurf, and any other MCP-compatible client to fetch real-time currency rates, historical data, and perform multi-currency lookups.

After installation, your assistant can answer questions such as:

• "What's the current USD to EUR rate?"
• "Show me how GBP/JPY moved over the last 30 days."
• "Convert 250 USD into CAD at a real rate."
• "Compare USD against EUR, GBP, and JPY simultaneously."
• "List every supported currency."

🚀 Quick Start

This is a Model Context Protocol server that allows compatible clients to access real - time currency rates and related data. First, you need to obtain an API key, then install the server, and finally configure it according to different clients.

✨ Features

• Rich Currencies: Support over 150 ISO 4217 codes, covering all major and most exotic currencies.
• High - Frequency Updates: Mid - market rates are refreshed approximately every 60 seconds.
• Historical Data: Provide up to 1 - year historical data with different granularities (1d, 7d, 30d, 1y).
• Multiple Tools: Expose 4 useful tools, including get_exchange_rate, get_historical_rates, get_rates_authenticated, and list_currencies.
• Compatible Transport: Use stdio (subprocess) and are MCP 1.x compatible.
• Runtime Requirement: Require Node.js ≥18.

📦 Installation

The server is published as an npm package. The simplest installation method is zero - install via npx, which is used in the following configurations.

# Run without installing (recommended)
npx -y @allratestoday/mcp-server

# Or install globally
npm install -g @allratestoday/mcp-server
allratestoday-mcp

Both commands start the stdio MCP server and wait for a client to connect. They are not intended to be run directly from the shell; instead, your MCP client should launch them as a subprocess.

💻 Usage Examples

Basic Usage

Each client reads MCP servers from different config files. Here are the configuration methods for different clients:

Claude Code

Use the built - in CLI:

claude mcp add allratestoday -- npx -y @allratestoday/mcp-server
claude mcp env allratestoday ALLRATES_API_KEY=art_live_xxxxx

Restart Claude Code. Verify by asking it: "What's the current USD to EUR rate?"

Cursor

Edit ~/.cursor/mcp.json (or .cursor/mcp.json inside your project for project - scoped servers):

{
  "mcpServers": {
    "allratestoday": {
      "command": "npx",
      "args": ["-y", "@allratestoday/mcp-server"],
      "env": {
        "ALLRATES_API_KEY": "art_live_xxxxx"
      }
    }
  }
}

Restart Cursor. The four tools should appear in the MCP tool picker.

Claude Desktop

Edit the config file (path depends on OS):

{
  "mcpServers": {
    "allratestoday": {
      "command": "npx",
      "args": ["-y", "@allratestoday/mcp-server"],
      "env": {
        "ALLRATES_API_KEY": "art_live_xxxxx"
      }
    }
  }
}

Fully quit and reopen Claude Desktop (Cmd + Q on macOS, right - click tray icon → Exit on Windows). Closing the window alone keeps the old config loaded.

Windsurf

Edit ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "allratestoday": {
      "command": "npx",
      "args": ["-y", "@allratestoday/mcp-server"],
      "env": {
        "ALLRATES_API_KEY": "art_live_xxxxx"
      }
    }
  }
}

Restart Windsurf.

Generic stdio MCP client

Any MCP host that supports stdio transport works. The launch command is:

npx -y @allratestoday/mcp-server

Set the environment variable ALLRATES_API_KEY. The protocol version is MCP 1.x.

Advanced Usage

Verify it works

After configuring your client, test in the following order:

1. Server starts: Open the client. If the MCP integration shows a red dot or "failed to connect", the API key is missing or wrong (see Troubleshooting).
2. Tools are listed: Most clients have a "tools" or "MCP" panel. You should see:
   • get_exchange_rate
   • get_historical_rates
   • get_rates_authenticated
   • list_currencies
3. A live call returns a number: Ask the assistant:

   What's the current USD to EUR rate? The assistant will call get_exchange_rate(source: "USD", target: "EUR") and reply with a real rate (e.g. "USD to EUR is currently 0.9214."). If it fabricates a number without making a tool call, the server isn't connected.

📚 Documentation

Tools reference

All four tools require an API key.

get_exchange_rate

Get the current mid - market rate between two currencies.

Input

Example call

{ "source": "USD", "target": "EUR" }

Example response

{ "rate": 0.92145, "source": "wise" }

get_historical_rates

Get time - series data points for a currency pair over a fixed period.

Input

Granularity by period

Example call

{ "source": "USD", "target": "INR", "period": "30d" }

Example response (truncated)

{
  "source": "USD",
  "target": "INR",
  "period": "30d",
  "data": [
    { "date": "2026-03-27T00:00:00Z", "rate": 83.42, "timestamp": 1743033600000 },
    { "date": "2026-03-28T00:00:00Z", "rate": 83.51, "timestamp": 1743120000000 },
    "..."
  ]
}

get_rates_authenticated

Get rates for multiple targets in one call, with optional historical timestamp or grouping window.

Input

Example call

{ "source": "USD", "target": "EUR,GBP,JPY" }

Example response

[
  { "rate": 0.9214, "source": "USD", "target": "EUR", "time": "2026-04-26T11:00:00Z" },
  { "rate": 0.7891, "source": "USD", "target": "GBP", "time": "2026-04-26T11:00:00Z" },
  { "rate": 151.34, "source": "USD", "target": "JPY", "time": "2026-04-26T11:00:00Z" }
]

list_currencies

Get all supported currencies with codes, names, and symbols. Cached upstream for 24 hours.

Input — none.

Example response (truncated)

{
  "currencies": [
    { "code": "USD", "name": "US Dollar", "symbol": "$" },
    { "code": "EUR", "name": "Euro", "symbol": "€" },
    { "code": "GBP", "name": "British Pound", "symbol": "£" },
    "..."
  ],
  "count": 162
}

Environment variables

You should set these in your MCP client's config (in the env block), not in your shell, because MCP servers are launched as subprocesses with isolated environments.

🔧 Technical Details

Troubleshooting

Inspect server logs

To see what the server is doing, run it manually with the API key set:

ALLRATES_API_KEY=art_live_xxxxx npx -y @allratestoday/mcp-server

You should see no output when healthy (stdio is reserved for the MCP protocol). Any errors print to stderr.

Error reference

The server maps API errors to clear, actionable messages.

The LLM will surface these messages in its response, so a user prompt that hits a 429 results in the assistant saying "the API quota has been exceeded — please try again next month or upgrade your plan."

📄 License

MIT — see LICENSE.