Skip to main content

MCP Python SDK

Python implementation of the Model Context Protocol (MCP)

PyPI MIT licensed Python Version Documentation Protocol Specification

[!NOTE] This is v2 of the MCP Python SDK, the current stable release line. It is a major rework of the SDK, both to support the 2026-07-28 MCP specification (and every earlier revision) and to fix long-standing architectural issues. Coming from v1? See What's new in v2 for the tour of what changed and the migration guide for every breaking change.

Not ready to migrate? v1.x lives on the v1.x branch, continues to receive critical bug fixes and security patches, and is documented at https://py.sdk.modelcontextprotocol.io/v1/. Since pip install mcp now installs 2.x, keep a <2 upper bound on your requirement (for example mcp>=1.28,<2) until you've migrated.

Something rough, confusing, or broken? Open an issue or find us in #python-sdk-dev on the MCP Contributors Discord.

Documentation

The documentation lives at https://py.sdk.modelcontextprotocol.io/.

It has a Get started guide, What's new in v2, the API reference, and the migration guide.

What is MCP?

The Model Context Protocol lets you build servers that expose data and functionality to LLM applications in a secure, standardized way. Think of it like a web API, but designed for LLM interactions. With this SDK you can:

  • Build MCP servers that expose tools, resources, and prompts to any MCP host
  • Build MCP clients that connect to any MCP server
  • Speak every standard transport: stdio, Streamable HTTP, and SSE

Requirements

Python 3.10+.

Installation

uv add "mcp[cli]"      # or: pip install "mcp[cli]"

The cli extra adds the mcp command-line tool (mcp dev, mcp run, mcp install) on top of the SDK; install plain mcp if you don't need it. For one-off commands, uv run --with "mcp[cli]" mcp ... works without a project.

A server in 15 lines

Create a server.py:

from mcp.server import MCPServer

mcp = MCPServer("Demo")


@mcp.tool()
def add(a: int, b: int) -> int:
    """Add two numbers."""
    return a + b


@mcp.resource("greeting://{name}")
def greeting(name: str) -> str:
    """Greet someone by name."""
    return f"Hello, {name}!"

Full example: docs_src/index/tutorial001.py

That's a complete MCP server: one tool, one templated resource. Open it in the MCP Inspector:

uv run mcp dev server.py

Call add with a=1, b=2 and you get 3 back.

Notice what you did not write: no JSON Schema (a: int, b: int is the schema), no request parsing, no validation code, no protocol handling. Two type-hinted Python functions and a docstring.

Get started takes it from here.

A client in 10 lines

The same package is a full MCP client. Serve server.py over HTTP:

uv run mcp run server.py --transport streamable-http

then point a Client at it:

import asyncio

from mcp import Client


async def main() -> None:
    async with Client("http://localhost:8000/mcp") as client:
        result = await client.call_tool("add", {"a": 1, "b": 2})
        print(result.structured_content)  # {'result': 3}


asyncio.run(main())

A URL means Streamable HTTP, the transport you deploy. Client can also launch a local server as a stdio subprocess or take any custom transport; Clients has the rest.

Contributing

We are passionate about supporting contributors of all levels of experience and would love to see you get involved in the project. See the contributing guide to get started.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

mcp-2.1.1.tar.gz (4.0 MB view details)

Uploaded Source

Built Distribution

If you're not sure about the file name format, learn more about wheel file names.

mcp-2.1.1-py3-none-any.whl (357.9 kB view details)

Uploaded Python 3

File details

Details for the file mcp-2.1.1.tar.gz.

File metadata

  • Download URL: mcp-2.1.1.tar.gz
  • Upload date:
  • Size: 4.0 MB
  • Tags: Source
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/7.0.0 CPython/3.13.14

File hashes

Hashes for mcp-2.1.1.tar.gz
Algorithm Hash digest
SHA256 50b7ba1ebbe117008ea7bdd288234043e69c20b403d6851d19661e6d431a75ef
MD5 c164f76cff04da9e638e53b33f0d62d5
BLAKE2b-256 d46e21fb8e5d579dbe21d96ea4d5034200d46d8bdf2261053b5bd041f3c2f612

See more details on using hashes here.

Provenance

The following attestation bundles were made for mcp-2.1.1.tar.gz:

Publisher: publish-pypi.yml on modelcontextprotocol/python-sdk

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file mcp-2.1.1-py3-none-any.whl.

File metadata

  • Download URL: mcp-2.1.1-py3-none-any.whl
  • Upload date:
  • Size: 357.9 kB
  • Tags: Python 3
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/7.0.0 CPython/3.13.14

File hashes

Hashes for mcp-2.1.1-py3-none-any.whl
Algorithm Hash digest
SHA256 1c6c31c5d6471c58db76af3af8af67f46d11d01f0a59077d0a308cbdb3d3e915
MD5 049e8569b7d26839151ecde1b2a5f5d0
BLAKE2b-256 50af8644cc5fa26a59afd2df2e98eeb19e72926887fa4b7441aba4ff661140db

See more details on using hashes here.

Provenance

The following attestation bundles were made for mcp-2.1.1-py3-none-any.whl:

Publisher: publish-pypi.yml on modelcontextprotocol/python-sdk

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

Release history Release notifications | RSS feed

This release

2.1.1 This release

2 files

2.1.0

2 files

2.0.1

2 files

2.0.0

2 files

1.29.1

2 files

1.29.0

2 files

1.28.1

2 files

1.28.0

2 files

1.27.2

2 files

1.27.1

2 files

1.27.0

2 files

1.26.0

2 files

1.25.0

2 files

1.24.0

2 files

1.23.3

2 files

1.23.2

2 files

1.23.1

2 files

1.23.0

2 files

1.22.0

2 files

1.21.2

2 files

1.21.1

2 files

1.21.0

2 files

1.20.0

2 files

1.19.0

2 files

1.18.0

2 files

1.17.0

2 files

1.16.0

2 files

1.15.0

2 files

1.14.1

2 files

1.14.0

2 files

1.13.1

2 files

1.13.0

2 files

1.12.4

2 files

1.12.3

2 files

1.12.2

2 files

1.12.1

2 files

1.12.0

2 files

1.11.0

2 files

1.10.1

2 files

1.10.0

2 files

1.9.4

2 files

1.9.3

2 files

1.9.2

2 files

1.9.1

2 files

1.9.0

2 files

1.8.1

2 files

1.8.0

2 files

1.7.1

2 files

1.7.0

2 files

1.6.0

2 files

1.5.0

2 files

1.4.1

2 files

1.4.0

2 files

1.3.0

2 files

1.2.1

2 files

1.2.0

2 files

1.1.3

2 files

1.1.2

2 files

1.1.1

2 files

1.1.0

2 files

1.0.0

2 files

0.9.1

2 files

Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page