A rails gem that allows you to use the fast and compact msgpack serialization for ActiveRec/ActiveRes
Ruby JavaScript
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.



Uses the fast and compact msgpack binary format to let you serialize objects.


In your Gemfile include the following line:

gem 'msgpack-rails', :git => 'git://github.com/nzifnab/msgpack-rails.git'


To encode objects use msgpack's to_msgpack method:

@person = Person.new(:first_name => 'bob', :last_name => 'joe')

In your controller's render action (to be consumed as an API like ActiveResource):

respond_to do |format|
    format.mpac { render :text => @person.to_msgpack, :content_type => 'application/x-mpac' }

Additionally you can set up ActiveResource to accept :mpac content types:

class Animal < ActiveResource::Base
  self.format = :msgpack

# Meanwhile, across the desert...

Animal.find(1)   # =>  Expects the content to be in the msgpack format


  1. Serialization options hash

    It is currently more limiting than to_json or to_xml in that the 'options' hash does not (yet) work. If you want the equivalent of this from json:

     @person.to_json(:include => [:group], :methods => [:monkey_see])

    Then you have to generate it as a hash manually:

     @person.serializable_hash(:include => [:group], :methods => [:monkey_see]).to_msgpack

    I plan on finding a way to get this working as the other two format methods do, but for now this work-around should be fine.

  2. Date formats

    The msgpack gem (written in C) does not natively serialize date formats. Instead, I convert the dates to a string and send them that way. This is bad, because they are seen by the ActiveResource endpoint as a string and are not converted to a date. You need to keep this in mind and may have to use to_datetime on dates in those models.


  1. Fix the two gotchas mentioned above

  2. Better render support in the controller (something like render :mpac => @person.to_msgpack without the :content_type requirement)

  3. Better support and testing for rails 2.3 (maybe, but low priority)


If you use or are interested in the msgpack gem (even by itself) and want to or already do use it in Rails (with or without this msgpack-rails gem) I would love to hear about your experiences! What did you do to get it to work for you?

If you have suggestions, ideas, or have taken a look at this gem's code and want to help improve it (fixing bugs, adding additional features, etc) then that's great! Fork the project, make a 'feature branch' with your suggested changes (preferably one major 'feature' per branch/pull request), and then do a pull request from that branch. Feel free to discuss with me ideas etc in the issues tracker here on github.

This project is licensed under the MIT-LICENSE.