Frankfurter MCP Server

frankfurter-mcp

Official Model Context Protocol server for the Frankfurter exchange-rate API. A thin, stateless proxy over Frankfurter's v2 blended multi-source reference rates.

Tools

• get_rates — blended rates. No date = latest; date = that day; start+end = time series (requires quotes). Optional base, quotes, providers.
• convert — convert an amount between two currencies; returns the rate used.

Rates are daily reference rates, not real-time trading rates. Not financial advice.

Run

npm install
npm run build
npm start            # listens on :3000, POST /mcp

Docker:

docker build -t frankfurter-mcp . && docker run -p 3000:3000 frankfurter-mcp
docker run -p 3000:3000 ghcr.io/lineofflight/frankfurter-mcp:latest

The prebuilt ghcr.io/lineofflight/frankfurter-mcp image is available once package publishing is enabled for the repo; building from source always works.

Point any MCP client at http://<host>:3000/mcp (Streamable HTTP).

Configuration

• PORT — HTTP port (default 3000).
• FRANKFURTER_API_URL — upstream API base (default https://api.frankfurter.dev). Set this to a self-hosted Frankfurter instance if desired. The value must be a host root: any path prefix in it is discarded (e.g. https://example.com/api resolves to https://example.com/v2/rates), so a self-hosted instance must be reachable at the host root.

Development

npm test       # vitest
npm run lint   # biome

License

MIT