MCP, or Model Context Protocol, is a protocol created by Anthropic (the creators of Claude) to streamline and standardise LLM (large language model) access to external tools and resources.

FastMCP is a Python framework that allows you to implement MCP in your Python applications.

In this article, I'll walk you through creating an Exchange Rate MCP server that you can use in your coding agent, Claude Desktop, or any other MCP-compatible environment to get current exchange rates.

What really is the point of MCP?

LLMs, such as ChatGPT, Gemini, and Claude models, are trained on vast datasets up to a specific date, known as the knowledge cut-off date.

This is fine when you ask them about anything historical, but the moment you ask for something current — "what's the USD to EUR rate right now?" — they'll either guess based on stale training data or, worse, hallucinate a number that looks plausible but is completely wrong.…