msgpack-python

MessagePack (de)serializer.

msgpack-python v0.5.6 1.3M downloads/30d#4,098 on PyPI

Permissive license Apache 2.0 Abandoned released 2018-03-10

What it is and what it does

msgpack-python is a deprecated binary serialization library that once provided MessagePack encoding and decoding for Python. It was last released on 2018-03-10 and has been abandoned since then. The package itself directs all users to install msgpack instead, which is the actively maintained successor.

Do not install this package for new projects. If you encounter it as a transitive dependency, update your dependency tree to use msgpack directly. The high install friction combined with complete abandonment makes this package unsuitable for any current use.

Use it for:

Maintaining legacy code that explicitly requires msgpack-python==0.5.6 and cannot be updated (not recommended).
Understanding historical Python serialization libraries, but only for educational purposes.
Migrating away from msgpack-python to msgpack as part of a deprecation cleanup.

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

MessagePack serialization and deserialization for Python; this package is deprecated and should not be used—install msgpack instead.

No. Do not install msgpack-python. The package is deprecated, abandoned, and explicitly directs users to install msgpack instead. Use msgpack for any new or existing projects that need MessagePack serialization.

Install

msgpack-python on PyPI

pip

pip install msgpack-python

uv

uv add msgpack-python

poetry

poetry add msgpack-python

Installing msgpack-python

Before you install

High install friction and abandoned maintenance status. Last release was 2018-03-10, many years ago. The package itself declares deprecation in its description and directs users to install msgpack instead.

License in practice

Licensed under Apache 2.0 (permissive), which poses no legal barrier, but the deprecation status makes the license terms moot for new projects.

Quickstart

# Do not use this package. Install msgpack instead.
# If you must use the deprecated msgpack-python:
# pip install msgpack-python==0.5.6
import msgpack

Package is deprecated; use msgpack instead. Requires Python 2.7 or 3.5+ based on classifiers, but no longer maintained.

Verify before relying

Whether msgpack is a drop-in substitute or requires code changes.
Current state of downstream projects still depending on msgpack-python and their migration status.

Package facts

License	Apache 2.0 (permissive)
Python support	not specified
Install friction	high — source build required
Runtime dependencies	none
Maintenance	abandoned — 3,079 days since the last release
First released	2010-04-29
Downloads	1,293,583/month — #4,098 on PyPI (30-day window, as of 2026-08-14)
Known vulnerabilities	none known (OSV.dev, checked 2026-08-14)

Evidence: msgpack-python-0.5.6.tar.gz

Intended Audience :: DevelopersLicense :: OSI Approved :: Apache Software LicenseProgramming Language :: Python :: 2Programming Language :: Python :: 2.7Programming Language :: Python :: 3Programming Language :: Python :: 3.5Programming Language :: Python :: 3.6Programming Language :: Python :: 3.7Programming Language :: Python :: Implementation :: CPythonProgramming Language :: Python :: Implementation :: PyPy