# MCP Python SDK — Build MCP Servers & Clients

> Build MCP servers and clients in Python with FastMCP, plus a CLI for dev and install flows; supports stdio, SSE, and Streamable HTTP transports.

## Install

Save as a script file and run:

# MCP Python SDK — Build MCP Servers & Clients

> Build MCP servers and clients in Python with FastMCP, plus a CLI for dev and install flows; supports stdio, SSE, and Streamable HTTP transports.

## Quick Use

1. Install:
   ```bash
   pip install "mcp[cli]"
   ```
2. Run:
   ```bash
   python -c "import mcp; print('mcp installed')"
   ```
3. Verify:
   - Run one FastMCP demo server and confirm a tool call succeeds in the MCP inspector.


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## Intro

Build MCP servers and clients in Python with FastMCP, plus a CLI for dev and install flows; supports stdio, SSE, and Streamable HTTP transports.

- **Best for:** Python teams building their own MCP tools (servers) or integrating MCP into internal agent runtimes
- **Works with:** Python, uv/pip workflows, MCP transports (stdio/SSE/streamable HTTP) and FastMCP decorators
- **Setup time:** 15 minutes


### Quantitative Notes

- PyPI install group: `mcp[cli]` (repo docs)
- GitHub stars + forks (verified): see Source & Thanks
- Setup time ~15 minutes (Python env + one demo server + inspector)


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## Practical Notes

A minimal, reliable path is: build one FastMCP server with 1–2 tools, run it in dev mode, then validate with the official inspector. Only after that, add auth/env handling and move to HTTP transports. If you’re using Claude Code, prefer explicit install steps and keep tool inputs narrow and typed.

**Safety note:** Don’t expose unconstrained exec/file tools over HTTP without an allowlist and auditing; MCP transports are powerful by design.

### FAQ

**Q: Is this only for servers?**
A: No. The SDK supports both building servers and writing MCP clients that connect to servers.

**Q: Which transport should I pick?**
A: Use stdio for local tools, and Streamable HTTP for production-like deployments; SSE is also supported.

**Q: Do I need uv?**
A: No. uv is recommended in docs, but pip works too (`pip install "mcp[cli]"`).

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## Source & Thanks

> GitHub: https://github.com/modelcontextprotocol/python-sdk
> Owner avatar: https://avatars.githubusercontent.com/u/182288589?v=4
> License (SPDX): MIT
> GitHub stars (verified via `api.github.com/repos/modelcontextprotocol/python-sdk`): 22,953
> GitHub forks (verified via `api.github.com/repos/modelcontextprotocol/python-sdk`): 3,411


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<!-- ZH -->

# MCP Python SDK——用 Python 写 MCP Server/Client

> 用 Python 构建 MCP server/client：提供 FastMCP 与 CLI 开发工具，支持 stdio、SSE 与 Streamable HTTP 传输，便于本地调试与集成。

## 快速使用

1. 安装：
   ```bash
   pip install "mcp[cli]"
   ```
2. 运行：
   ```bash
   python -c "import mcp; print('mcp installed')"
   ```
3. 验证：
   - Run one FastMCP demo server and confirm a tool call succeeds in the MCP inspector.


---

## 简介

用 Python 构建 MCP server/client：提供 FastMCP 与 CLI 开发工具，支持 stdio、SSE 与 Streamable HTTP 传输，便于本地调试与集成。

- **适合谁（Best for）:** 需要自建 MCP 工具（server）或把 MCP 接入内部 agent 运行时的 Python 团队
- **兼容工具（Works with）:** Python、uv/pip 工作流、MCP 传输（stdio/SSE/streamable HTTP）与 FastMCP 装饰器
- **安装时间（Setup time）:** 15 分钟


### 量化信息

- PyPI 安装可选组：`mcp[cli]`（仓库文档）
- GitHub stars + forks（已核验）：见「来源与感谢」
- 跑通约 15 分钟（Python 环境 + demo server + inspector）


---

## 实战要点

最稳的落地路径：先用 FastMCP 写一个只包含 1–2 个工具的 server，用 dev 模式跑起来，再用官方 inspector 验证工具调用链路；跑通后再加鉴权/环境变量管理，并迁移到 HTTP 传输。如果接入 Claude Code，建议显式安装流程，并把工具入参做小且类型化。

**安全提示：** 不要在 HTTP 传输上暴露无约束的 exec/文件工具；MCP 天生能力强，需要白名单与审计配套。

### FAQ

**Q: 只能写 server 吗？**
A: 不是。SDK 既能写 MCP server，也能写 MCP client 去连接现有 server。

**Q: 传输协议怎么选？**
A: 本地工具优先 stdio；更接近生产的部署用 Streamable HTTP；SSE 也支持。

**Q: 一定要用 uv 吗？**
A: 不必须。文档推荐 uv，但 pip 同样可用（`pip install "mcp[cli]"`）。

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## 来源与感谢

> GitHub：https://github.com/modelcontextprotocol/python-sdk
> Owner avatar：https://avatars.githubusercontent.com/u/182288589?v=4
> 许可证（SPDX）：MIT
> GitHub stars（已通过 `api.github.com/repos/modelcontextprotocol/python-sdk` 核验）：22,953
> GitHub forks（已通过 `api.github.com/repos/modelcontextprotocol/python-sdk` 核验）：3,411


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Source: https://tokrepo.com/en/workflows/mcp-python-sdk-build-mcp-servers-clients
Author: MCP Hub