Sequent is an opinionated CQRS and event sourcing framework (ES) written in Ruby. This site is intended to help you learn and develop CQRS / ES applications in Ruby (using Sequent). Sequent focusses on the domain logic of your application. It is web framework agnostic. You can use it with Rails, Sinatra or whatever framework you like.

Important: The entire documentation applies to the master branch


There are several tutorials available:

1. Getting Started

New to Sequent? The getting started guide is the place to be!

2. Modelling the domain

In this guide we will use the Sequent concepts and create and code a first domain model of our blog application. Go checkout the modelling the domain guide for step by step tutorial to create an app from scatch.

3. Building a web-application

In the building a web-application guide we continue with the application created in the modelling the domain guide and add a web interface for it using the Sinatra web framework.

4. Finishing the webapplication

In the finishing the web-application guide we continue with the blog application and add form validation and let the Author’s add Posts.

5. Rails & Sequent

The Rails & Sequent guide shows how to use Sequent in a Rails application.

Reference Guide

Next to the tutorials there is the Reference Guide to provide and in-depth explanation of the several concepts (like AggregateRoot, Event, Command etc) used in Sequent.

Further reading

There is a lot more information available on CQRS and event sourcing:


Sequent is released under the MIT License.