Low-level access

Let’s recap how we first build a server so we can easily compare it to how low-level access is different. Here’s how you build a simple MCP server with a high-level API:

from mcp.server.fastmcp import FastMCP
mcp = FastMCP("Echo")
@mcp.resource("echo://{message}")
def echo_resource(message: str) -> str:
    """Echo a message as a resource"""
    return f"Resource echo: {message}"
@mcp.tool()
def echo_tool(message: str) -> str:
    """Echo a message as a tool"""
    return f"Tool echo: {message}"

The FastMCP class is what you use to instantiate a server – in this case, an instance called mcp. Then we use @mcp to define resources, tools, and prompts.

This is a high-level way of building a server, but what if you want more control over how the server is built? Here’s how you can do that using low-level access.

Let’...