This module provides a Ruby interface for data serialization in YAML format.

The YAML module is an alias for Psych, the YAML engine for Ruby.


Add this line to your application's Gemfile:

gem 'yaml'

And then execute:

$ bundle

Or install it yourself as:

$ gem install yaml


Working with YAML can be very simple, for example:

require 'yaml'

# Parse a YAML string
YAML.load("--- foo") #=> "foo"

# Emit some YAML
YAML.dump("foo")     # => "--- foo\n...\n"
{ :a => 'b'}.to_yaml  # => "---\n:a: b\n"

For detailed documentation, see Psych.


Do not use YAML to load untrusted data. Doing so is unsafe and could allow malicious input to execute arbitrary code inside your application.


Syck was the original for YAML implementation in Ruby's standard library developed by why the lucky stiff.

You can still use Syck, if you prefer, for parsing and emitting YAML, but you must install the 'syck' gem now in order to use it.

In older Ruby versions, ie. <= 1.9, Syck is still provided, however it was completely removed with the release of Ruby 2.0.0.

More info

For more advanced details on the implementation see Psych, and also check out http://yaml.org for spec details and other helpful information.

Psych is maintained by Aaron Patterson on github: https://github.com/tenderlove/psych

Syck can also be found on github: https://github.com/tenderlove/syck


After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.


Bug reports and pull requests are welcome on GitHub at https://github.com/ruby/yaml.