Prefixed IDs

🆔 Friendly Prefixed IDs for your Ruby on Rails models

Build Status Gem Version

Generate prefixed IDs for your models with a friendly prefix. For example:


Inspired by Stripe's prefixed IDs in their API.

🚀 Installation

Add this line to your application's Gemfile:

gem 'prefixed_ids'

📝 Usage

Add has_prefix_id :my_prefix to your models to autogenerate prefixed IDs.

class User < ApplicationRecord
  has_prefix_id :user

This will generate a value like user_1234abcd.

To query using the prefixed ID, simply you can use either find or find_by_prefixed_id:


We also override to_param by default so it'll be used in URLs automatically.

To disable find and to_param overrides, simply pass in the options:

class User < ApplicationRecord
  has_prefix_id :user, override_find: false, override_param: false

Generic lookup

Imagine you have a prefixed ID but you don't know which model it belongs to.

#=> #<User>
#=> #<Account>


You can customize the prefix, length, and attribute name for PrefixedIds.

class Account < ApplicationRecord
  has_prefix_id :acct, minimum_length: 32, override_find: false, to_param: false


After checking out the repo, run bin/setup to install dependencies. Then, run rake test 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 the created tag, and push the .gem file to

🙏 Contributing

Bug reports and pull requests are welcome on GitHub at This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

📝 License

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

Code of Conduct

Everyone interacting in the PrefixedIds project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.