MCP Server — connect AI to interest rate data

What is MCP, and why does it matter?

The Model Context Protocol (MCP) lets AI assistants call external tools and fetch live data mid-conversation, instead of relying on outdated training data. Point an MCP-compatible agent at our endpoint and it can pull real interest rate data — current or historical — the moment you ask.

Example: ask Claude "What's the spread between SOFR and EURIBOR 3M right now?" and it calls the latest tool automatically — no manual API calls, no copy-pasting JSON.

Available MCP tools

Seven tools, one per REST endpoint — see the full API reference for parameters.

Getting started

One endpoint for every client. Authenticate with your API key as a header or query parameter — no separate MCP credential to manage.

Send your API key one of three ways:

• Authorization: Bearer YOUR_API_KEY
• X-API-Key: YOUR_API_KEY
• ?apikey=YOUR_API_KEY on the URL itself — for clients whose config only accepts a plain URL

Need a key first? Register for a free trial, then grab it from your dashboard.

Connect Claude Desktop / claude.ai

Add a custom connector with the endpoint URL and your key embedded as a query parameter — the simplest option for clients that only take a plain URL.

{
  "mcpServers": {
    "interestratesapi": {
      "url": "https://mcp.interestratesapi.com/mcp?apikey=YOUR_API_KEY"
    }
  }
}

On claude.ai, add it under Settings → Connectors → Add custom connector with the same URL (including ?apikey=) as the remote server address. Restart Claude Desktop after editing the config file.

Connect Claude Code (CLI)

Add the server with your key as an auth header, from any terminal:

claude mcp add --transport http interestratesapi https://mcp.interestratesapi.com/mcp \
  --header "Authorization: Bearer YOUR_API_KEY"

Then, inside a Claude Code session, run /mcp to confirm it's connected, or claude mcp list from the terminal.

Connect Cursor

Add to ~/.cursor/mcp.json (or .cursor/mcp.json in a project for a project-only setup):

{
  "mcpServers": {
    "interestratesapi": {
      "url": "https://mcp.interestratesapi.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

Save, then fully quit and reopen Cursor. Try: "What's the current Fed Funds Rate?"

Python example

A minimal client that calls the latest tool over MCP's JSON-RPC 2.0 protocol.

import httpx
import json
import asyncio

MCP_SERVER_URL = "https://mcp.interestratesapi.com/mcp"
API_KEY = "YOUR_API_KEY"

async def call_mcp_tool(tool_name: str, arguments: dict):
    async with httpx.AsyncClient(timeout=30) as client:
        init_response = await client.post(
            MCP_SERVER_URL,
            headers={"Authorization": f"Bearer {API_KEY}"},
            json={
                "jsonrpc": "2.0",
                "id": "1",
                "method": "initialize",
                "params": {
                    "protocolVersion": "2024-11-05",
                    "capabilities": {},
                    "clientInfo": {"name": "PythonClient", "version": "1.0.0"},
                },
            },
        )
        session_id = init_response.headers.get("Mcp-Session-Id")

        response = await client.post(
            MCP_SERVER_URL,
            headers={"Authorization": f"Bearer {API_KEY}", "Mcp-Session-Id": session_id},
            json={
                "jsonrpc": "2.0",
                "id": "2",
                "method": "tools/call",
                "params": {"name": tool_name, "arguments": arguments},
            },
        )
        return response.json()

async def main():
    result = await call_mcp_tool("latest", {"symbols": "FED_FUNDS,SOFR"})
    print(json.dumps(result, indent=2))

asyncio.run(main())

Frequently asked questions