MCP服务器磁盘使用情况（演示）
什么是MCP？
模型上下文协议（MCP）是一种协议，它使像Claude这样的AI模型能够与外部工具和服务进行交互。它允许Claude访问实时系统信息并代表您执行操作。
了解有关MCP的更多信息：
所得
当与Claude Desktop集成时，此演示MCP服务器使Claude能够实时检查您的磁盘使用情况（在Mac上）。以下是一个交互示例：
!
用户：“我当前的磁盘使用情况如何？”
克劳德：“让我帮你查一下你当前的磁盘使用情况。”
\[批准使用磁盘使用工具，用户同意\]
View result from ``get_disk_usage` from `disk-usage`` (local)
{
"device": "/dev/disk3s5",
"total_gb": "228.0GB",
"used_gb": "177.0GB",
"available_gb": "27.0GB",
"reserved_gb": "24.0GB",
"percent_used": "87%",
"mount": "/System/Volumes/Data",
"summary": "Total: 228.0GB | Used: 177.0GB | Available: 27.0GB | Reserved: 24.0GB | Usage: 87%"
}Claude：“这是您当前的磁盘使用信息：
总磁盘空间：228.0GB\ 使用空间：177.0GB\ 可用空间：27.0GB\ 预留空间：24.0GB\ 使用率：87%\ 安装点：/系统/体积/数据\ 设备：/dev/disk3s5
您的磁盘当前容量为87%，还有27.0GB的可用空间。如果你担心高使用率，你可能想考虑清理一些文件以释放更多空间。"
运作原理
服务器功能
当服务器启动时，它通过MCP协议向Claude通告其功能。以下是克劳德所看到的：
@mcp.tool()
def get_disk_usage() -> Dict[str, str]:
"""Get current disk usage information for the system disk
Returns:
A dictionary containing disk usage information with fields:
- device: Device name
- total_gb: Total size in GB
- used_gb: Used space in GB
- available_gb: Available space in GB
- reserved_gb: Space reserved by system in GB
- percent_used: Usage percentage
- mount: Mount point
- summary: Human-readable summary of disk usage
"""这个告诉克劳德：
- 服务器提供了一个名为
get_disk_usage - 该工具返回一个包含详细磁盘信息的字典
- docstring解释了每个字段的含义
完整的Claude MCP交互流程
- 克劳德的初始系统提示:
You are Claude, an AI assistant. You have access to these tools:
get_disk_usage() -> Dict[str, str]
"Get current disk usage information for the system disk"
To use this tool, respond with a XML block:
get_disk_usage
Explain why you need disk usage information
- 用户查询:
User: What is my current disk usage?- Claude的工具选择响应:
I'll check your disk usage information.
get_disk_usage
User has requested current disk usage information. This tool will provide detailed statistics about disk space utilization.
- 克劳德桌面应用程序→ MCP服务器:
// HTTP POST to MCP Server
{
"jsonrpc": "2.0",
"method": "invoke",
"params": {
"tool": "get_disk_usage",
"args": {}
},
"id": 1
}- MCP服务器→ 克劳德桌面应用程序:
{
"jsonrpc": "2.0",
"result": {
"device": "/dev/disk3s5",
"total_gb": "228.0GB",
"used_gb": "177.0GB",
"available_gb": "27.0GB",
"reserved_gb": "24.0GB",
"percent_used": "87%",
"mount": "/System/Volumes/Data",
"summary": "Total: 228.0GB | Used: 177.0GB | Available: 27.0GB | Reserved: 24.0GB | Usage: 87%"
},
"id": 1
}- 向Claude提出新请求 （以工具输出作为上下文）：
User: What is my current disk usage?
Tool Response:
{
"device": "/dev/disk3s5",
"total_gb": "228.0GB",
"used_gb": "177.0GB",
"available_gb": "27.0GB",
"reserved_gb": "24.0GB",
"percent_used": "87%",
"mount": "/System/Volumes/Data",
"summary": "Total: 228.0GB | Used: 177.0GB | Available: 27.0GB | Reserved: 24.0GB | Usage: 87%"
}
Provide a helpful response to the user based on this disk usage information.- 克劳德的最终回应:
Here's your current disk usage information:
Total Disk Space: 228.0GB
Used Space: 177.0GB
Available Space: 27.0GB
Reserved Space: 24.0GB
Usage Percentage: 87%
Mount Point: /System/Volumes/Data
Device: /dev/disk3s5
Your disk is currently at 87% capacity, with 27.0GB of space still available. If you're concerned about the high usage, you might want to consider cleaning up some files to free up more space.这显示了完整的流程：
- Claude从了解可用工具开始
- 用户提问
- Claude认识到需要磁盘信息，并建议使用该工具
- 批准后，工具响应被注入到对话中
- Claude将原始数据处理成有用的响应
技术实现
# Tool advertisement from server
{
"tools": [
{
"name": "get_disk_usage",
"description": "Get current disk usage information for the system disk",
"parameters": {}, # No parameters needed
"returns": {
"type": "object",
"properties": {
"device": {"type": "string"},
"total_gb": {"type": "string"},
"used_gb": {"type": "string"},
"available_gb": {"type": "string"},
"reserved_gb": {"type": "string"},
"percent_used": {"type": "string"},
"mount": {"type": "string"},
"summary": {"type": "string"}
}
}
}
]
}- 用户查询:
User: "What is my current disk usage?"- 克劳德的工具选择:
Claude认识到此查询需要磁盘信息，并决定使用 get_disk_usage 工具。
Claude: "Let me check your current disk usage for you."
[approval to use disk-usage tool, user gives consent]- 工具调用和响应:
// Raw tool response
{
"device": "/dev/disk3s5",
"total_gb": "228.0GB",
"used_gb": "177.0GB",
"available_gb": "27.0GB",
"reserved_gb": "24.0GB",
"percent_used": "87%",
"mount": "/System/Volumes/Data",
"summary": "Total: 228.0GB | Used: 177.0GB | Available: 27.0GB | Reserved: 24.0GB | Usage: 87%"
}- 克劳德的自然反应:
Claude处理原始数据并提供人性化的响应：
Here's your current disk usage information:
Total Disk Space: 228.0GB
Used Space: 177.0GB
Available Space: 27.0GB
Reserved Space: 24.0GB
Usage Percentage: 87%
Mount Point: /System/Volumes/Data
Device: /dev/disk3s5
Your disk is currently at 87% capacity, with 27.0GB of space still available. If you're concerned about the high usage, you might want to consider cleaning up some files to free up more space."通信协议
在幕后，MCP通过WebSocket使用双向JSON-RPC协议。其工作原理如下：
- 初始化:
// Claude -> Server
{
"jsonrpc": "2.0",
"method": "initialize",
"params": {
"protocolVersion": "2024-11-05",
"capabilities": {},
"clientInfo": {
"name": "claude-ai",
"version": "0.1.0"
}
},
"id": 0
}- 工具广告:
服务器以其功能进行响应，包括 get_disk_usage 工具及其模式。
- 工具调用:
// Claude -> Server
{
"jsonrpc": "2.0",
"method": "invoke",
"params": {
"tool": "get_disk_usage",
"args": {}
},
"id": 1
}- 服务器响应:
// Server -> Claude
{
"jsonrpc": "2.0",
"result": {
"device": "/dev/disk3s5",
"total_gb": "228.0GB",
"used_gb": "177.0GB",
...
},
"id": 1
}此基于WebSocket的协议允许：
- 持久连接
- 双向通信
- 结构化类型信息
- 工具发现和文档
实施
- MCP服务器(
disk_usage_server.py)使用Pythonsubprocess模块来运行df命令 - 它特别关注
/System/Volumes/Data分区（macOS上的磁盘3s5） - 服务器解析输出并返回结构化数据，包括：
- 总磁盘空间 - 已用空间 - 可用空间 - 预留空间（系统预留的空间） - 使用百分比 - 安装点和设备信息
需求
- macOS（此工具专为Mac的磁盘结构而设计）
- Python 3.11+
- pip（Python包管理器）
运行服务器
- 克隆此存储库
- 安装依赖项：
pip install -r requirements.txt- 运行服务器：
python disk_usage_server.py备注：此服务器专门查找 /System/Volumes/Data macOS上的分区（disk3s5）。它不适用于其他操作系统。
Claude桌面集成
- 创建一个
claude-config.txtClaude Desktop配置目录中的文件（通常~/.config/claude-desktop/在macOS上），使用：
{
"mcpServers": {
"disk-usage": {
"command": "python3",
"args": [
"
/disk_usage_server.py"
]
}
}
}- 替换 `
` 保存服务器文件的实际路径
- 重新启动克劳德桌面
学习成果
该项目展示了：
- 如何使用Python创建一个简单的MCP服务器
- 如何将系统命令集成到MCP工具中
- 如何为AI消费构建数据结构
- 如何处理系统特定的细节（如磁盘分区）
- 如何提供清晰、易读的技术数据摘要
文件
disk_usage_server.py：主MCP服务器实现requirements.txt：Python依赖关系claude-config.txt：克劳德桌面配置示例