# Rails Event Store

> Rails Event Store (RES) is an open-source library for Ruby and Rails for publishing, consuming, storing, and retrieving events. It helps applications adopt event-driven architecture and decouple business logic.

RES can be used as a publish-subscribe bus, an alternative to ActiveRecord callbacks, an audit log, and a foundation for read models and event sourcing. Event handlers can run synchronously or asynchronously. Event sourcing is one use case, not a requirement for using RES.

The project is funded and maintained by Arkency and released under the MIT license. Ruby Event Store can also be used without Rails.

The documentation links below use the default published version. For version-specific API details, select the documentation version matching the application's gems; `/docs/master/` covers development rather than a published release.

## Getting started

- [Homepage](https://railseventstore.org/): Project overview and use cases.
- [Introduction](https://railseventstore.org/docs/getting-started/introduction): Create a Rails application with RES and find the next steps.
- [Installation](https://railseventstore.org/docs/getting-started/install): Add and configure RES in an existing Rails application.
- [API documentation](https://railseventstore.org/docs/getting-started/api): Generated API references for the project's gems.
- [Using Ruby Event Store without Rails](https://railseventstore.org/docs/advanced-topics/without-rails): Integrate the event store with other Ruby applications.

## Core concepts

- [Publishing events](https://railseventstore.org/docs/core-concepts/publish): Define domain events and publish them to streams.
- [Subscribing to events](https://railseventstore.org/docs/core-concepts/subscribe): Register synchronous and asynchronous event handlers.
- [Reading events](https://railseventstore.org/docs/core-concepts/read): Query events, select streams, and control ordering and batching.
- [Event sourcing](https://railseventstore.org/docs/core-concepts/event-sourcing): Model and persist event-sourced aggregates with AggregateRoot.
- [Projections](https://railseventstore.org/docs/core-concepts/projections): Derive state from a stream of events.
- [Browser](https://railseventstore.org/docs/core-concepts/browser): Inspect streams and events in a web interface for debugging and audit logs.
- [RSpec matchers](https://railseventstore.org/docs/core-concepts/rspec): Test domain events and their publication.

## Project and support

- [Source code](https://github.com/RailsEventStore/rails_event_store): Repository containing the Ruby gems and this website.
- [Releases](https://github.com/RailsEventStore/rails_event_store/releases): Release notes and version history.
- [Support](https://railseventstore.org/support): Community help, learning resources, and paid support from Arkency.
- [Contributing](https://railseventstore.org/contributing): Contribution policy and development guidance.

## Optional

- [Community](https://railseventstore.org/community): Articles, talks, example applications, and community resources.
- [Billetto case study](https://railseventstore.org/billetto): How a ticketing platform uses Rails Event Store in production.