rails breaking changes

rubygems

4 curated breaking changes across major versions of rails. Use this as a migration checklist before bumping dependencies.

changes

Breaking changes by transition

7 \u2192 8api
Solid Queue, Solid Cable, Solid Cache built-in — PostgreSQL/MySQL/SQLite backed; Redis no longer required for jobs / ActionCable / cache.
Migration
New apps get Solid* defaults. Existing apps can opt in via `bin/rails solid_queue:install`. Redis-based Sidekiq continues to work.
7 \u2192 8api
Built-in authentication generator: `bin/rails generate authentication`. Kamal 2 is the default deployment tool.
Migration
Opt-in. Devise / Clearance / Rodauth continue to work. For deployment, `config/deploy.yml` is new — Capistrano still supported.
7 \u2192 8runtime
Ruby 3.2+ required.
Migration
Upgrade Ruby: `rbenv install 3.3.0 && rbenv local 3.3.0`. Rails 8 officially tests on 3.2, 3.3, 3.4.
6 \u2192 7config
Hotwire (Turbo + Stimulus) is the default front-end stack. Webpacker deprecated (removed in 7.1).
Migration
New apps: no change needed. Existing apps: keep Webpacker for a release or migrate via `bin/rails app:update` + switch to importmap-rails or jsbundling-rails.

API access

Get this data programmatically \u2014 free, no authentication.

curl https://depscope.dev/api/breaking/rubygems/rails