Rails CLI In-Depth Reference

Complete reference for the Rails CLI surface — commands, generators, database tasks, rake tasks, flags, positional arguments, and shell completion targets. Built for creating a carapace completer.

Data Flow

bin/rails COMMAND [args] [options]
  ├── rails new          → AppGenerator (Thor)
  ├── rails generate     → GenerateCommand → Generator subclasses
  ├── rails server       → ServerCommand (Rack/Puma)
  ├── rails console      → ConsoleCommand (IRB)
  ├── rails dbconsole    → DbconsoleCommand (psql/mysql/sqlite3)
  ├── rails runner       → RunnerCommand (eval code)
  ├── rails test         → TestCommand → Minitest
  ├── rails routes       → RoutesCommand (router inspection)
  ├── rails db:          → Rake tasks (Active Record)
  ├── rails credentials  → CredentialsCommand (encrypted YAML)
  ├── rails encrypted    → EncryptedCommand (generic encrypted files)
  ├── rails notes        → NotesCommand (annotation grep)
  ├── rails query        → QueryCommand (Active Record REPL)
  └── rails <task>       → Rake fallback (Thor delegate)

Sub-Resources

Load the reference that matches your task. When in doubt, load multiple references.

Keywords	Reference
rails new, AppGenerator, --database, --javascript, --css, --api, --minimal, --skip-*, --template, --rc, .railsrc, --dev, --edge, --main, --devcontainer, PluginGenerator	references/rails-new.md
rails generate, rails destroy, generator subcommands, model, scaffold, resource, controller, migration, job, mailer, channel, mailbox, task, helper, jbuilder, system_test, integration_test, generator, application_record, benchmark, scaffold_controller, --skip-routes, --parent, --timestamps, --api, --queue, --assets, --actions, field:type:index, --pretend, --force, --skip, orm hook, template_engine hook, test_framework hook	references/generators.md
rails server, rails console, rails runner, rails dbconsole, rails routes, middleware, initializers, about, stats, boot, dev:cache, restart, secret, version, encrypted, credentials, notes, query, devcontainer, --port, --binding, --sandbox, --environment, --database, --unused, --expanded, --controller, --grep, --enroll, --disenroll	references/cli-commands.md
rails db:*, database rake tasks, migrate, schema, seed, rollback, create, drop, setup, reset, prepare, version, encryption, truncate, charset, collation, fixtures, test:db, multi-db, db:system:change, --to, VERSION, STEP, SCOPE, FIXTURES, FIXTURES_DIR	references/database.md
rails test, test:system, test:all, test:functionals, test:units, test:generators, test:models, test:helpers, test:channels, test:controllers, test:mailers, test:integration, test:jobs, test:mailboxes, test:db, --name, --verbose, --seed, --warnings, --environment	references/testing.md
rails log:clear, tmp:, time:zones, yarn:install, zeitwerk:check, action_mailbox:, action_text:install, active_storage:*, app:template, railties:install:migrations, javascript:install	references/rake-tasks.md
config/application.rb, config/environment.rb, config/boot.rb, config.ru, config/database.yml, config/environments/.rb, config/initializers/, config/routes.rb, config.load_defaults, config.time_zone, config.eager_load, config.cache_classes, config.enable_reloading, config.log_level, config.cache_store, config.session_store, config.autoload_paths, config.consider_all_requests_local, config.force_ssl, config.hosts, config.active_record., config.action_controller., config.action_mailer., config.active_storage., config.action_dispatch., config.assets.*, config.generators, config.x, before_configuration, before_initialize, after_initialize, to_prepare, before_eager_load, initialization queue, boot sequence, Rails::Application	references/configuration.md
RAILS_ENV, RACK_ENV, RAILS_MASTER_KEY, SECRET_KEY_BASE, DATABASE_URL, BUNDLE_GEMFILE, RAILS_RELATIVE_URL_ROOT, RAILS_CACHE_ID, RAILS_APP_VERSION, RAILS_DEVELOPMENT_HOSTS, RAILS_MAX_THREADS, RAILS_MIN_THREADS, RAILS_SERVE_STATIC_FILES, RAILS_LOG_TO_STDOUT, WEB_CONCURRENCY, PORT, VERSION, STEP, SCOPE, VERBOSE, FIXTURES, FIXTURES_DIR, FIXTURES_PATH, LOGS, URL, INGEST_PASSWORD	references/environment.md

Quick Guide

• How do I complete rails new flags? → references/rails-new.md
• How do I complete rails generate <thing>? → references/generators.md
• What flags does rails server accept? → references/cli-commands.md
• What are all the db:* subcommands? → references/database.md
• How do I complete test paths and subcommands? → references/testing.md
• What --environment values are valid? → The string environment — value can be any string, typically development, test, production, or staging. Not enum-limited.
• How does --database work in rails new? → references/rails-new.md
• What field types does generate model accept? → references/generators.md
• How does multi-db completion work for db:* tasks? → references/database.md
• What are the rails credentials:* subcommands? → references/cli-commands.md
• How does db:system:change --to= work? → references/database.md
• What are the aliases for rails commands? → references/cli-commands.md
• How do I complete rails encrypted:edit/show? → references/cli-commands.md
• What does config.load_defaults do? → references/configuration.md
• How does the Rails boot sequence work? → references/configuration.md
• What are the config/environments/*.rb settings? → references/configuration.md
• How does config/database.yml work with multi-db? → references/configuration.md
• What environment variables does Rails recognize? → references/environment.md
• How does DATABASE_URL interact with config/database.yml? → references/environment.md
• What is RAILS_MASTER_KEY used for? → references/environment.md
• How do RAILS_ENV and RACK_ENV relate? → references/environment.md

Cross-Project References

• For Ruby language fundamentals (classes, blocks, gems, Bundler), consult Ruby's official documentation — Rails is a Ruby framework and its configuration DSLs are Ruby-based.
• For Bundler (bundle, Gemfile, BUNDLE_GEMFILE), consult Bundler's official documentation — this skill covers only how Rails uses Bundler in config/boot.rb.
• For Puma server internals (puma.rb, threads, workers, RAILS_MAX_THREADS), consult Puma's official documentation — this skill documents only the Rails-side conventions in config/puma.rb.
• For carapace completion integration (the rails completer in carapace-bin, specs, actions, macros), see the carapace skill.
• For Thor (the CLI framework Rails uses for generators and commands), consult Thor's official documentation.