https://github.com/msgpack/msgpack-ruby

MessagePack implementation for Ruby / msgpack.org[Ruby]
https://github.com/msgpack/msgpack-ruby

Keywords

msgpack

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rubygems mvc activerecord activejob fluentd ruby-gem cncf data-collector nokogiri libxml2

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MessagePack implementation for Ruby / msgpack.org[Ruby]

Host: GitHub
URL: https://github.com/msgpack/msgpack-ruby
Owner: msgpack
License: apache-2.0
Created: 2011-09-29T04:10:15.000Z (over 14 years ago)
Default Branch: master
Last Pushed: 2025-12-11T22:06:54.000Z (3 months ago)
Last Synced: 2026-02-28T22:12:55.944Z (3 days ago)
Topics: msgpack
Language: Ruby
Homepage: http://msgpack.org/
Size: 6.2 MB
Stars: 775
Watchers: 21
Forks: 121
Open Issues: 2
Releases: 0
Metadata Files:
- Readme: README.md
- Changelog: ChangeLog
- License: LICENSE

MessagePack

MessagePack is an efficient binary serialization format.
It lets you exchange data among multiple languages like JSON but it's faster and smaller.
For example, small integers (like flags or error code) are encoded into a single byte,
and typical short strings only require an extra byte in addition to the strings themselves.

If you ever wished to use JSON for convenience (storing an image with metadata) but could
not for technical reasons (binary data, size, speed...), MessagePack is a perfect replacement.

require 'msgpack'
msg = [1,2,3].to_msgpack  #=> "\x93\x01\x02\x03"
MessagePack.unpack(msg)   #=> [1,2,3]

Add msgpack to your Gemfile to install with Bundler:

# Gemfile
gem 'msgpack'

Or, use RubyGems to install:

gem install msgpack

Or, build msgpack-ruby and install from a checked-out msgpack-ruby repository:

bundle
rake
gem install --local pkg/msgpack

Use cases

Create REST API returing MessagePack using Rails + RABL
Store objects efficiently serialized by msgpack on memcached or Redis
- In fact Redis supports msgpack in EVAL-scripts
Upload data in efficient format from mobile devices such as smartphones
- MessagePack works on iPhone/iPad and Android. See also Objective-C and Java implementations
Design a portable protocol to communicate with embedded devices
- Check also Fluentd which is a log collector which uses msgpack for the log format (they say it uses JSON but actually it's msgpack, which is compatible with JSON)
Exchange objects between software components written in different languages
- You'll need a flexible but efficient format so that components exchange objects while keeping compatibility

Portability

MessagePack for Ruby should run on x86, ARM, PowerPC, SPARC and other CPU architectures.

And it works with MRI (CRuby) and Rubinius.
Patches to improve portability are highly welcomed.

Serializing objects

Use MessagePack.pack or to_msgpack:

require 'msgpack'
msg = MessagePack.pack(obj)  # or
msg = obj.to_msgpack
File.binwrite('mydata.msgpack', msg)

Streaming serialization

Packer provides advanced API to serialize objects in streaming style:

# serialize a 2-element array [e1, e2]
pk = MessagePack::Packer.new(io)
pk.write_array_header(2).write(e1).write(e2).flush

See API reference for details.

Deserializing objects

Use MessagePack.unpack:

require 'msgpack'
msg = File.binread('mydata.msgpack')
obj = MessagePack.unpack(msg)

Streaming deserialization

Unpacker provides advanced API to deserialize objects in streaming style:

# deserialize objects from an IO
u = MessagePack::Unpacker.new(io)
u.each do |obj|
  # ...
end

or event-driven style which works well with EventMachine:

# event-driven deserialization
def on_read(data)
  @u ||= MessagePack::Unpacker.new
  @u.feed_each(data) {|obj|
     # ...
  }
end

See API reference for details.

Serializing and deserializing symbols

By default, symbols are serialized as strings:

packed = :symbol.to_msgpack     # => "\xA6symbol"
MessagePack.unpack(packed)      # => "symbol"

This can be customized by registering an extension type for them:

MessagePack::DefaultFactory.register_type(0x00, Symbol)

# symbols now survive round trips
packed = :symbol.to_msgpack     # => "\xc7\x06\x00symbol"
MessagePack.unpack(packed)      # => :symbol

The extension type for symbols is configurable like any other extension type.
For example, to customize how symbols are packed you can just redefine
Symbol#to_msgpack_ext. Doing this gives you an option to prevent symbols from
being serialized altogether by throwing an exception:

class Symbol
  def to_msgpack_ext
    raise "Serialization of symbols prohibited"
  end
end

MessagePack::DefaultFactory.register_type(0x00, Symbol)

[1, :symbol, 'string'].to_msgpack  # => RuntimeError: Serialization of symbols prohibited

Serializing and deserializing Time instances

There are the timestamp extension type in MessagePack,
but it is not registered by default.

To map Ruby's Time to MessagePack's timestamp for the default factory:

MessagePack::DefaultFactory.register_type(
  MessagePack::Timestamp::TYPE, # or just -1
  Time,
  packer: MessagePack::Time::Packer,
  unpacker: MessagePack::Time::Unpacker
)

See API reference for details.

Extension Types

Packer and Unpacker support Extension types of MessagePack.

# register how to serialize custom class at first
pk = MessagePack::Packer.new(io)
pk.register_type(0x01, MyClass1, :to_msgpack_ext) # equal to pk.register_type(0x01, MyClass)
pk.register_type(0x02, MyClass2){|obj| obj.how_to_serialize() } # blocks also available

# almost same API for unpacker
uk = MessagePack::Unpacker.new()
uk.register_type(0x01, MyClass1, :from_msgpack_ext)
uk.register_type(0x02){|data| MyClass2.create_from_serialized_data(data) }

MessagePack::Factory is to create packer and unpacker which have same extension types.

factory = MessagePack::Factory.new
factory.register_type(0x01, MyClass1) # same with next line
factory.register_type(0x01, MyClass1, packer: :to_msgpack_ext, unpacker: :from_msgpack_ext)
pk = factory.packer(options_for_packer)
uk = factory.unpacker(options_for_unpacker)

For MessagePack.pack and MessagePack.unpack, default packer/unpacker refer MessagePack::DefaultFactory. Call MessagePack::DefaultFactory.register_type to enable types process globally.

MessagePack::DefaultFactory.register_type(0x03, MyClass3)
MessagePack.unpack(data_with_ext_typeid_03) #=> MyClass3 instance

Alternatively, extension types can call the packer or unpacker recursively to generate the extension data:

Point = Struct.new(:x, :y)
factory = MessagePack::Factory.new
factory.register_type(
  0x01,
  Point,
  packer: ->(point, packer) {
    packer.write(point.x)
    packer.write(point.y)
  },
  unpacker: ->(unpacker) {
    x = unpacker.read
    y = unpacker.read
    Point.new(x, y)
  },
  recursive: true,
)
factory.load(factory.dump(Point.new(12, 34))) # => #<struct Point x=12, y=34>

Pooling

Creating Packer and Unpacker objects is expensive. For best performance it is preferable to re-use these objects.

MessagePack::Factory#pool makes that easier:

factory = MessagePack::Factory.new
factory.register_type(
  0x01,
  Point,
  packer: ->(point, packer) {
    packer.write(point.x)
    packer.write(point.y)
  },
  unpacker: ->(unpacker) {
    x = unpacker.read
    y = unpacker.read
    Point.new(x, y)
  },
  recursive: true,
)
pool = factory.pool(5) # The pool size should match the number of threads expected to use the factory concurrently.

pool.load(pool.dump(Point.new(12, 34))) # => #<struct Point x=12, y=34>

Buffer API

MessagePack for Ruby provides a buffer API so that you can read or write data by hand, not via Packer or Unpacker API.

This MessagePack::Buffer is backed with a fixed-length shared memory pool which is very fast for small data (<= 4KB),
and has zero-copy capability which significantly affects performance to handle large binary data.

How to build and run tests

Before building msgpack, you need to install bundler and dependencies.

gem install bundler
bundle install

Then, you can run the tasks as follows:

Build

bundle exec rake build

Run tests

bundle exec rake spec

Generating docs

bundle exec rake doc

How to build -java rubygems

To build -java gems for JRuby, run:

rake build:java

If this directory has Gemfile.lock (generated with MRI), remove it beforehand.

Updating documents

Online documentation (https://ruby.msgpack.org) is generated from the gh-pages branch.
To update documents in gh-pages branch:

bundle exec rake doc
git checkout gh-pages
cp -a doc/* ./

Copyright

Author
- Sadayuki Furuhashi frsyuki@gmail.com
Copyright
- Copyright (c) 2008-2015 Sadayuki Furuhashi
License
- Apache License, Version 2.0

Owner metadata

Name: MessagePack
Login: msgpack
Email:
Kind: organization
Description:
Website: http://msgpack.org/
Location:
Twitter:
Company:
Icon url: https://avatars.githubusercontent.com/u/198264?v=4
Repositories: 22
Last ynced at: 2024-03-25T19:32:16.069Z
Profile URL: https://github.com/msgpack

GitHub Events

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Fork event: 5
Issues event: 6
Watch event: 9
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Last Year

Pull request event: 5
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Pull request review event: 1
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Committers metadata

Last synced: 1 day ago

Total Commits: 1,873
Total Committers: 106
Avg Commits per committer: 17.67
Development Distribution Score (DDS): 0.706

Commits in past year: 5
Committers in past year: 3
Avg Commits per committer in past year: 1.667
Development Distribution Score (DDS) in past year: 0.6

Name	Email	Commits
frsyuki	f**i@u**p	550
TAGOMORI Satoshi	t**s@g**m	210
gfx	g**i@c**g	146
Jean Boussier	j**r@g**m	121
tokuhirom	t**m@g**m	94
Muga Nishizawa	m**a@g**m	81
frsyuki	f**i@5**1	55
Muga Nishizawa	m**a@f**)	51
INADA Naoki	s**y@g**m	50
Hideyuki Tanaka	t**i@g**m	38
UENISHI Kota	k**b@g**m	34
Theo	t**o@i**t	29
Naoki INADA	i**n@e**e	24
Tokuhiro Matsuno	t**m@u**p	20
makamaka	m**o@g**m	18
Aaron Patterson	a**n@g**m	17
Naoki INADA	i**n@k**p	16
Gustav Munkby	g**v@g**m	14
Vincent de Phily	v**y@g**m	14
Naoki INADA	i**n@g**r	13
Kazuki Ohta	k**a@g**m	13
Olle Jonsson	o**n@g**m	13
moriyoshi	m**o@m**p	13
Kazuki Oikawa	k@o****g	12
frsyuki	f**i@v**)	11
frsyuki (none)	f**i@v**.	11
Christopher Aue	m**l@c**t	11
Kazuki Ohta	k**k@i**p	10
Koichiro Ohba	k**o@m**g	10
takeshita	t**a@g**m	9
and 76 more...

Committer domains:

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Last synced: 2 months ago

Total issues: 44
Total pull requests: 125
Average time to close issues: over 1 year
Average time to close pull requests: about 1 month
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Merged pull request: 104
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Past year issues: 1
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Past year average time to close issues: 2 days
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Package metadata

Total packages: 6
Total downloads:
- rubygems: 913,344,698 total
Total docker downloads: 4,269,847,084
Total dependent packages: 330 (may contain duplicates)
Total dependent repositories: 282,509 (may contain duplicates)
Total versions: 587
Total maintainers: 6

gem.coop: msgpack

MessagePack is a binary-based efficient object serialization library. It enables to exchange structured objects between many languages like JSON. But unlike JSON, it is very fast and small.

Homepage: http://msgpack.org/
Documentation: http://www.rubydoc.info/gems/msgpack/
Licenses: Apache 2.0
Latest release: 1.8.0 (published about 1 year ago)
Last Synced: 2026-03-01T21:01:36.597Z (2 days ago)
Versions: 254
Dependent Packages: 0
Dependent Repositories: 0
Downloads: 456,657,761 Total
Docker Downloads: 2,134,923,542
Rankings:
- Dependent repos count: 0.0%
- Dependent packages count: 0.0%
- Average: 0.026%
- Downloads: 0.052%
- Docker downloads count: 0.052%
Maintainers (5)
- naruse
- byroot
- tagomoris
- chrisseaton
- frsyuki

rubygems.org: msgpack

MessagePack is a binary-based efficient object serialization library. It enables to exchange structured objects between many languages like JSON. But unlike JSON, it is very fast and small.

Homepage: http://msgpack.org/
Documentation: http://www.rubydoc.info/gems/msgpack/
Licenses: Apache 2.0
Latest release: 1.8.0 (published about 1 year ago)
Last Synced: 2026-03-02T01:01:41.051Z (2 days ago)
Versions: 259
Dependent Packages: 329
Dependent Repositories: 282,509
Downloads: 456,685,117 Total
Docker Downloads: 2,134,923,542
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- Dependent packages count: 0.135%
- Average: 0.813%
- Stargazers count: 2.125%
- Forks count: 2.412%
Maintainers (5)
- naruse
- byroot
- tagomoris
- chrisseaton
- frsyuki

proxy.golang.org: github.com/msgpack/msgpack-ruby

Homepage:
Documentation: https://pkg.go.dev/github.com/msgpack/msgpack-ruby#section-documentation
Licenses: apache-2.0
Latest release: v1.8.0 (published about 1 year ago)
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Versions: 65
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- Dependent packages count: 5.48%
- Average: 5.664%
- Dependent repos count: 5.848%

gem.coop: ed-precompiled_msgpack

MessagePack is a binary-based efficient object serialization library. It enables to exchange structured objects between many languages like JSON. But unlike JSON, it is very fast and small.

Homepage: https://msgpack.org/
Documentation: http://www.rubydoc.info/gems/ed-precompiled_msgpack/
Licenses: Apache-2.0
Latest release: 1.8.0 (published 5 months ago)
Last Synced: 2026-02-28T21:01:09.632Z (3 days ago)
Versions: 3
Dependent Packages: 0
Dependent Repositories: 0
Downloads: 910 Total
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- Stargazers count: 2.214%
- Forks count: 2.468%
- Average: 20.833%
- Downloads: 99.482%
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- edouardchin

conda-forge.org: rb-msgpack

Homepage: https://rubygems.org/gems/msgpack
Licenses: Apache-2.0
Latest release: 1.4.2 (published over 4 years ago)
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- Forks count: 15.488%
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- Dependent packages count: 28.82%
- Dependent repos count: 34.025%

rubygems.org: ed-precompiled_msgpack

MessagePack is a binary-based efficient object serialization library. It enables to exchange structured objects between many languages like JSON. But unlike JSON, it is very fast and small.

Homepage: https://msgpack.org/
Documentation: http://www.rubydoc.info/gems/ed-precompiled_msgpack/
Licenses: Apache-2.0
Latest release: 1.8.0 (published 5 months ago)
Last Synced: 2026-02-28T21:01:09.585Z (3 days ago)
Versions: 3
Dependent Packages: 0
Dependent Repositories: 0
Downloads: 910 Total
Rankings:
- Stargazers count: 2.074%
- Forks count: 2.315%
- Dependent packages count: 14.231%
- Average: 30.853%
- Dependent repos count: 43.59%
- Downloads: 92.056%
Maintainers (1)
- edouardchin

Dependencies

Gemfile rubygems

rubocop ~> 0.82.0
simplecov >= 0

msgpack.gemspec rubygems

bundler >= 0 development
json >= 0 development
rake >= 0 development
rake-compiler >= 1.1.9 development
rspec ~> 3.3 development
yard >= 0 development

.github/workflows/ci.yaml actions

actions/checkout v2 composite
ruby/setup-ruby v1 composite

Score: 33.687621519161596

https://github.com/msgpack/msgpack-ruby

Keywords

Keywords from Contributors

Repository metadata

README.md

MessagePack

Use cases

Portability

Serializing objects

Streaming serialization

Deserializing objects

Streaming deserialization

Serializing and deserializing symbols

Serializing and deserializing Time instances

Extension Types

Pooling

Buffer API

How to build and run tests

Build

Run tests

Generating docs

How to build -java rubygems

Updating documents

Copyright

Owner metadata

GitHub Events

Total

Last Year

Committers metadata

Committer domains:

Issue and Pull Request metadata

Top Issue Authors

Top Pull Request Authors

Top Issue Labels

Top Pull Request Labels

Package metadata

gem.coop: msgpack

rubygems.org: msgpack

proxy.golang.org: github.com/msgpack/msgpack-ruby

gem.coop: ed-precompiled_msgpack

conda-forge.org: rb-msgpack

rubygems.org: ed-precompiled_msgpack

Dependencies