UUID’s in Rails + SQLite shouldn’t be this hard (so I built a gem)

Source: Dev.to

TL;DR – UUIDs / ULIDs in a Rails + SQLite app

# Gemfile
gem "sqlite_crypto"

# migration
create_table :users, id: :uuid do |t|
  t.string :email
  t.timestamps
end

That’s it.
Foreign keys are auto‑detected, schema.rb stays clean, everything just works.

[→ GitHub] | [→ RubyGems]

The problem I ran into

I was building a Rails 8 app that used SQLite as its production database (thanks to the new WAL‑mode defaults, better busy‑handler handling, etc.). When I tried to add UUID primary keys, SQLite behaved nothing like PostgreSQL.

What broke

What I had to do before writing the gem

1. Verbose migration syntax

   create_table :users, id: false do |t|
     t.string :id, limit: 36, null: false, primary_key: true
     t.string :email
     t.timestamps
   end

2. Manual type specification on every foreign key

   create_table :api_keys, id: false do |t|
     t.string :id, limit: 36, null: false, primary_key: true
     t.references :user, null: false, foreign_key: true,
                       type: :string, limit: 36
   end

3. Custom UUID generation in ApplicationRecord

   class ApplicationRecord
     # example UUID
     "550e8400-e29b-41d4-a716-446655440000"
   end
   
   user.tracking_id  #=> "01ARZ3NDEKTSV4RRFFQ69G5FAV"

Benchmarks

If you’re curious, I prepared a spec especially for checking each ID type’s performance. Run it on your own hardware:

bundle exec rspec --tag performance

Registering custom types

ActiveRecord::Type.register(:uuid, SqliteCrypto::Type::Uuid, adapter: :sqlite3)

The hard part was getting the schema dumper to output clean id: :uuid instead of verbose column definitions. That required prepending modules at exactly the right point in Rails’ initialization sequence.

CI matrix

My CI matrix tests against:

• Ruby 3.1 – 3.4
• Rails 7.1 – 8.1

I discovered edge cases that only appear in specific combinations—Rails 8.0’s schema dumper behaved differently than 7.2’s in subtle ways.

Installation

# Gemfile
gem "sqlite_crypto"

If you hit issues, open a GitHub issue. If it helps your project, consider starring the repo—it helps others discover the gem.

Links

• GitHub Repository – https://github.com/yourname/sqlite_crypto
• RubyGems – https://rubygems.org/gems/sqlite_crypto
• Changelog – https://github.com/yourname/sqlite_crypto/blob/main/CHANGELOG.md

Contributing

If you’ve been thinking about contributing to the Ruby ecosystem but haven’t started — I encourage you to do it. Building sqlite_crypto taught me more about Rails internals than years of application development. The community needs tools, and you might be the person to build the next one.

If you see gaps in your Rails + SQLite workflow, feel free to share them with me. I’m genuinely curious about other pain points in this new SQLite‑first world.

Get in touch

Building something with sqlite_crypto? I’d love to hear about it. Drop a comment or find me on GitHub.