Anyone who works with Ruby on Rails applications knows that, as a project grows, quickly understanding the relationships between models can become increasingly difficult.
Even when using traditional ERD (Entity Relationship Diagram) generation tools, there is usually some friction in the workflow: generating files, manually updating diagrams, or relying on external processes.
With that in mind, I created the Rails Realtime ERD gem.
What is Rails Realtime ERD?
rails-realtime-erd is a Ruby on Rails gem that allows you to visualize your schema ERD diagrams in real time directly inside your application.
The idea is simple:
- Install the gem
- Add it to your project
- Open a route
- See your diagram automatically updated
No manual image generation. No intermediate exports. No leaving your application context.
Key Features
- ✅ Real-time schema visualization
- ✅ Simple integration with Rails applications
- ✅ Built on Rails Engine
- ✅ Automatic updates as your models evolve
- ✅ Integrated web interface
Perfect for:
- Understanding existing architectures
- Onboarding new developers
- Quickly exploring model relationships
- Keeping living documentation of your application's domain
Installation
Add the gem to your Gemfile:
gem "rails-realtime-erd"
Then run:
bundle install
Now simply access:
/rails/erd
in your project to visualize your diagram.
Why create this gem?
During consulting work, training sessions, and Rails application development, I often felt the lack of a more dynamic experience for inspecting an application's domain.
I wanted something closer to the experience we already have with:
/rails/mailers/sidekiq- internal dashboards
- integrated development tools
In other words: open a URL and start exploring immediately.
That's how Rails Realtime ERD was born.
Open Source Project
The gem is open source and available on GitHub:
Contributions, feedback, issues, and suggestions are very welcome.
If you work with Rails and enjoy tools that improve productivity and architectural understanding, give it a try.