---
id: msgpack
version: "1.2.1"
license: Apache-2.0
license_treatment: permissive
maintenance: active
---

# msgpack — MessagePack serializer

License: permissive · Maintenance: active · Popularity: top 1,000 on PyPI

## Install

pip install msgpack
uv add msgpack
poetry add msgpack

## Description

# MessagePack for Python

[![Build Status](https://github.com/msgpack/msgpack-python/actions/workflows/wheel.yml/badge.svg)](https://github.com/msgpack/msgpack-python/actions/workflows/wheel.yml)
[![Documentation Status](https://readthedocs.org/projects/msgpack-python/badge/?version=latest)](https://msgpack-python.readthedocs.io/en/latest/?badge=latest)

## What is this?

[MessagePack](https://msgpack.org/) is an efficient binary serialization format.
It lets you exchange data among multiple languages like JSON.
But it's faster and smaller.
This package provides CPython bindings for reading and writing MessagePack data.

## Install

```
$ pip install msgpack
```

### Pure Python implementation

The extension module in msgpack (`msgpack._cmsgpack`) does not support PyPy.

But msgpack provides a pure Python implementation (`msgpack.fallback`) for PyPy.


### Windows

If you can't use a binary distribution, you need to install Visual Studio
or the Windows SDK on Windows.
Without the extension, the pure Python implementation on CPython runs slowly.


## How to use

### One-shot pack & unpack

Use `packb` for packing and `unpackb` for unpacking.
msgpack provides `dumps` and `loads`...

## AI interpretation — verify before relying

msgpack is a fast binary serialization format that encodes Python objects into compact bytes and decodes them back, similar to JSON but smaller and quicker.

Verdict: msgpack is a stable, actively maintained serialization library (2,100 GitHub stars, no known vulnerabilities) suitable for production use. The Apache-2.0 license poses no restrictions. Medium install friction is manageable given broad wheel coverage; the pure Python fallback ensures PyPy compatibility.

[View on SkillFed](https://skillfed.io/packages/msgpack) · [View on PyPI](https://pypi.org/project/msgpack/)