MCP 协议 2025：AI 应用的 USB-C 标准

import ast
import subprocess
from pathlib import Path
from mcp.server import Server
from mcp.types import Tool, TextContent, Resource

app = Server("code-analyzer")

# 注册工具
@app.list_tools()
async def list_tools() -> list[Tool]:
    return [
        Tool(
            name="analyze_python",
            description="分析 Python 代码中的问题",
            inputSchema={
                "type": "object",
                "properties": {
                    "code": {"type": "string", "description": "Python 代码"},
                },
                "required": ["code"],
            },
        ),
        Tool(
            name="run_tests",
            description="运行项目的测试用例",
            inputSchema={
                "type": "object",
                "properties": {
                    "path": {"type": "string", "description": "项目路径"},
                },
                "required": ["path"],
            },
        ),
    ]

@app.call_tool()
async def call_tool(name: str, arguments: dict) -> list[TextContent]:
    if name == "analyze_python":
        tree = ast.parse(arguments["code"])
        issues = []
        for node in ast.walk(tree):
            # 检查空 except
            if isinstance(node, ast.ExceptHandler) and node.type is None:
                issues.append("⚠️ 裸 except 会捕获所有异常，建议指定异常类型")
            # 检查函数是否过长
            if isinstance(node, ast.FunctionDef) and len(node.body) > 50:
                issues.append(f"⚠️ 函数 `{node.name}` 超过 50 行，建议拆分")
        
        return [TextContent(
            type="text",
            text= "\n".join(issues) if issues else "✅ 没有发现明显问题"
        )]
    
    elif name == "run_tests":
        result = subprocess.run(
            ["python", "-m", "pytest", arguments["path"], "-v"],
            capture_output=True, text=True, timeout=30
        )
        return [TextContent(type="text", text=result.stdout[-2000:])]

# 注册资源（暴露可访问的数据）
@app.list_resources()
async def list_resources() -> list[Resource]:
    return [
        Resource(
            uri="project://config",
            name="项目配置文件",
            description="项目的 pyproject.toml 配置",
            mimeType="text/plain",
        )
    ]

if __name__ == "__main__":
    app.run(transport="stdio")