Bundler makes sure Ruby applications run the same code on every machine.

It does this by managing the gems that the application depends on. Given a list of gems, it can automatically download and install those gems, as well as any other gems needed by the gems that are listed. Before installing gems, it checks the versions of every gem to make sure that they are compatible, and can all be loaded at the same time. After the gems have been installed, Bundler can help you update some or all of them when new versions become available. Finally, it records the exact versions that have been installed, so that others can install the exact same gems.

To install (or update to the latest version):

gem install bundler

To install a prerelease version (if one is available), run gem install bundler --pre. To uninstall Bundler, run gem uninstall bundler.

Bundler is most commonly used to manage your application's dependencies. For example, these commands will allow you to use Bundler to manage the rspec gem for your application:

bundle init
bundle add rspec
bundle install
bundle exec rspec

See bundler.io for the full documentation.

For help with common problems, see TROUBLESHOOTING.

Still stuck? Try filing an issue.

To see what has changed in recent versions of Bundler, see the CHANGELOG.

To get in touch with the Bundler core team and other Bundler users, please see getting help.

If you'd like to contribute to Bundler, that's awesome, and we <3 you. We've put together the Bundler contributor guide with all of the information you need to get started.

If you'd like to request a substantial change to Bundler or to the Bundler documentation, refer to the Bundler RFC process for more information.

While some Bundler contributors are compensated by Ruby Together, the project maintainers make decisions independent of Ruby Together. As a project, we welcome contributions regardless of the author’s affiliation with Ruby Together.

Ruby Together pays some Bundler maintainers for their ongoing work. As a grassroots initiative committed to supporting the critical Ruby infrastructure you rely on, Ruby Together is funded entirely by the Ruby community. Contribute today as an individual or (better yet) as a company to ensure that Bundler, RubyGems, and other shared tooling is around for years to come.

Everyone interacting in the Bundler project’s codebases, issue trackers, chat rooms, and mailing lists is expected to follow the Bundler code of conduct.

Bundler is available under an MIT License.