MCP服务器新手教程2026

2026-08-01 约 5 分钟阅读

现在每个AI工具都提MCP，但没人从零讲起。

MCP Server Tutorial for Beginners 2026: From Zero to Your First AI Tool Integration

This tutorial assumes you have never heard of MCP before and want to understand it by doing. By the end you will have connected an AI assistant to a real external tool.

What You Are Building

An MCP server that lets Claude Desktop read a local todo list. When you ask "what is on my todo list?", Claude calls your server, reads the file, and answers.

Step 1: Understand the Three Roles

MCP Client - the AI assistant (Claude Desktop, Cline, etc.)
MCP Server - a small program that wraps a tool or data source
Transport - how they talk (stdio on your machine, HTTP over network)

Step 2: Write the Server

Create todo_server.py:

from mcp.server.fastmcp import FastMCP

mcp = FastMCP("Todo Server")

@mcp.tool()
def add_todo(item: str) -> str:
    with open("todos.txt", "a") as f:
        f.write(item + "
")
    return f"Added: {item}"

@mcp.tool()
def list_todos() -> str:
    try:
        with open("todos.txt") as f:
            return f.read() or "Empty"
    except FileNotFoundError:
        return "Empty"

Step 3: Register with Claude Desktop

Open Claude Desktop > Settings > Developer
Click Edit Config, add the server with command python and args pointing to your script
Restart Claude Desktop

Step 4: Use It

Type: "Add buy milk to my todo list, then show me the list."

Claude calls add_todo, then list_todos, and answers with the file contents. No prompt engineering, no glue code - the protocol did the wiring.

Common Beginner Mistakes

Mistake	Fix
Wrong path in args	Use absolute paths
Server crashes on start	Run python todo_server.py in terminal first to see errors
Claude says no tools available	Restart Claude after config changes
Windows npx errors	Use cmd /c npx ... as the command