Alfa state: direct full access to Java API ready for test, started adapter of remote objects - syntax sugar for direct access to remote objects.

This is an under-construction official gem from Universa to facilitate access to the Java library using Universa's UMI protocol.


  • added syntax sugar for TransactionPack

  • alfa version of the local FS-based contract store.

  • ability to edit contract.state and contract.transactional in new revisions.

  • fixed errors with interchange builder and set based objects

  • ruby sugar for Universa native classes: Role, Adapter, Contract, Binder, HashId.

  • Contract creation, revocation, changing owner in ruby way

  • Network operation for white keys/private networks: parallel state check, contract recistration.

This gem is already used in new Universa projects and is being actively tested.



JVM v1.8.* must be installed.


Add this line to your application's Gemfile:

gem 'universa'

And then execute:

$ bundle

Or install it yourself as:

$ gem install universa


Direct access to UMI

So far, you can only get direct access the the Java API functions. To get it:

require 'universa'

umi = Universa::UMI.new

p umi.version                                         #=> "0.8.8"
key = umi.instantiate "PrivateKey", 2048
contract = umi.instantiate "Contract", key
sealed = contract.seal()
puts "Contract is ok: #{contract.check()}"            #=> contract is ok: true"
puts "Contract id: #{contract.getId.toBase64String}"  #=> contract id: x9Ey+q...

# ruby-style snake case could also be used:
contract_id = contract.get_id.to_base64_string

Docs and resources

for more information see:

Use UMI service (alfa state)

The Universa::Service greatly simplify work taking all boilerplate. Just create objects almost as usual and use them as is they are local:

key = PrivateKey.new(open('mykey.private.unikey', 'rb').read)
contract = Contract.new(key)

p contract.check()

The system will create UMI server and do all the work for you. Look at the RemoteAdapter class to see how does it work. Soon we'll add adapters for all frequently used Universa classes.


After checking out the repo, run bin/setup to install dependencies. Then, run rake spec 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 github.com/[USERNAME]/universa. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.


The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Universa project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the of conduct[https://github.com/[USERNAME]/universa/blob/master/CODE_OF_CONDUCT.md].