Connect an agent to Bonds API

Tools

• latest

  Most recent sovereign yields for one or more countries and maturities. Maps to GET /api/v1/latest.

• historical

  Yield for one country, maturity, and past date. Maps to GET /api/v1/historical.

• timeseries

  Yield series for one country and maturity between two dates. Maps to GET /api/v1/timeseries.

• spread

  Yield spread of a country against a benchmark (Bund, Treasury). Maps to GET /api/v1/spread.

• curve

  Full sovereign curve for one country. Maps to GET /api/v1/curve.

• intraday

  Intraday snapshots for one country, maturity, and day. Professional plan. Maps to GET /api/v1/intraday.

• fluctuation

  Change, min, and max over a period for one or more countries. Maps to GET /api/v1/fluctuation.

Authentication

Two credentials work. There is no browser login and no public client ID to paste.

• API key. Create one after register, on API keys. Send it as X-API-Key: YOUR_API_KEY. A raw key in Authorization: Bearer is rejected.
• OAuth client credentials. POST https://bonds-api.com/oauth/token with grant_type=client_credentials. client_id is shown next to the key; client_secret is the key. The response is a one-hour access token. Send that token, and only that token, as Authorization: Bearer.

?apikey= on the MCP URL is accepted and forwarded as X-API-Key, but Claude Desktop and claude.ai strip query credentials from the saved connector URL. Do not use npx or mcp-remote.

Claude

1. Settings → Connectors → Add custom connector.
2. Name: Bonds API. Remote server URL: https://mcp.bonds-api.com/mcp. No key in the URL.
3. Claude will notice the 401 and may offer to connect. There is no Bonds login screen behind that button, and no client ID to fill in. Use Claude Code (or Cursor) to send X-API-Key.

claude mcp add --transport http bonds-api https://mcp.bonds-api.com/mcp --header "X-API-Key: YOUR_API_KEY"

Cursor

Cursor Settings → MCP, or ~/.cursor/mcp.json. Header, not query string.

{
  "mcpServers": {
    "bonds-api": {
      "url": "https://mcp.bonds-api.com/mcp",
      "headers": {
        "X-API-Key": "YOUR_API_KEY"
      }
    }
  }
}

ChatGPT

Settings → Connectors → custom MCP connector, remote URL https://mcp.bonds-api.com/mcp. Do not proxy this endpoint through the OpenAI API. A connector that only knows browser OAuth cannot attach an X-API-Key header; use Cursor or Claude Code for keyed calls.