Getting started

Kaui core mountable engine. For Kaui the UI, see killbill-admin-ui-standalone.

Kill Bill compatibility

Kaui version Kill Bill version
0.14.y 0.16.z
0.15.y 0.18.z (Rails 4)
0.16.y 0.18.z (Rails 5)
1.x.y 0.20.z (Rails 5)
2.x.y 0.22.z (Rails 5)


Ruby 2.4.2+ or JRuby required.

Running Kaui locally

Note: use Ruby, not JRuby, for running the app locally.

You can run Kaui locally by using the test/dummy app provided:

export RAILS_ENV=development DB_HOST= DB_USER=root DB_PASSWORD=root DB_PORT=3306
bundle install
bundle exec rails db:migrate
bundle exec rails s

The Kill Bill URL can be configured through the KILLBILL_URL environment variable, e.g.


Mounting Kaui into your own Rails app

The Kaui gem comes with a kaui script to mount it in your existing Rails app.

Kaui expects the container app to define the current_user method, which returns the name of the logged-in user. This is used by Kill Bill for auditing purposes.

Migrations can be copied over to your app via:

bundle exec rake kaui:install:migrations

Finally, a Kill Bill server needs to be running for Kaui to fetch its information (see the Configuration section below). The default login credentials are admin/password. Users, Credentials, Roles and Permissions are passed through to Kill Bill. It uses Basic Auth by default, but the backend is pluggable (LDAP, ActiveDirectory, etc.).

Running tests

rails t

Note: functional and integration tests require an instance of Kill Bill to test against.


Working with the kaui script

In order to generate the Rubygems-friendly kaui script, you need to build the gem and install it locally.

First, build the gem in the pkg directory:

rake build

Then, install and run it from a local directory:

mkdir foo
gem install pkg/kaui-*.gem -i foo
GEM_PATH=$PWD/foo:$GEM_PATH ./foo/bin/kaui /path/to/rails/app --path=$PWD --skip-bundle

Alternatively, you can run the kaui script under bin by setting your loadpath correctly:

ruby -Ilib bin/kaui /path/to/rails/app --path=$PWD --skip-bundle


KAUI has been enhanced to support multi-tenancy. In order to benefit from that mode, remove the properties KillBillClient.api_key and KillBillClient.api_secret from the config/initializers directory.

Admin User Roles

In multi-tenancy mode, there are two kinds of users:

  • The multi-tenant admin user, which has the rights to configure the tenant information (creation of tenant, add allowed users for specific tenant, upload catalog, ...)
  • The per-tenant admin user, which operates just a given tenant

Those roles and permissions are defined the same way other permissions are defined: The Shiro configuration (static config file, LDAP) in Kill Bill, will determine for each user its associated role, and the roles will have a set of available permissions. The new permissions have been created:


The enforcement in KAUI is based on the CanCan gem.

Multi-tenancy screens

KAUI has been enriched with new models and new screens to manage the multi-tenancy, and those are available for the multi-tenant admin user:

  • The kaui_tenants table will list the available tenants (from KAUI point of view); note that this is redundant with the Kill Bill tenants table, and the reason is that the api_secret needs to be maintained in KAUI as well, so listing the existing tenants from Kill Bill would not work since that key is encrypted and cannot be returned. A new screen mounted on /admin_tenants allows to configure new tenants. The view allows to create the new tenant in Kill Bill or simply updates the local KAUI config if the tenant already exists.
  • The kaui_allowed_users table along with the join table kaui_allowed_user_tenants will list all the users in the system that can access specific tenants. The join table is required since a given user could access multiple tenants (e.g multi-tenant admin user), and at the same time many users could access the same tenant. A new screen mounted on /admin_allowed_users allows to configure the set of allowed users associated to specific tenants.