majestic-rails

Implement state machines with AASM for workflow management. Covers state transitions, guards, callbacks, and testing.

Use when creating or refactoring Action Mailer emails. Applies Rails 7.1+ conventions, parameterized mailers, preview workflows, background delivery, and email design best practices.

Use proactively for authorization with ActionPolicy. Creates policies, scopes, and integrates with GraphQL/ActionCable. Preferred over Pundit for composable, cacheable authorization.

Implement typed business operations with ActiveInteraction. Covers input types, composition, controller patterns, and testing.

Use when creating or refactoring Active Job background jobs. Applies Rails 8 conventions, Solid Queue patterns, error handling, retry strategies, and job design best practices.

Use when implementing real-time features requiring reliability, especially LLM streaming. Applies AnyCable patterns for message delivery guarantees, presence tracking, and Action Cable migration.

Implement type-safe configuration with anyway_config gem. Use when creating configuration classes, replacing ENV access, or managing application settings. Triggers on configuration, environment variables, settings, secrets, or ENV patterns.

Route Rails business logic to the simplest fitting home: a model, typed operation, state machine, layered boundary, or durable event history.

Review data constraints and referential integrity in Rails models and migrations.

Write and review Ruby and Rails code using DHH and 37signals conventions. Use when implementing, refactoring, or reviewing Rails code for Rails-native simplicity, or when the user mentions DHH, 37signals, Basecamp, HEY, Fizzy, or Campfire.

Native HTML dialog patterns for Rails with Turbo and Stimulus. Use when building modals, confirmations, alerts, or any overlay UI. Triggers on modal, dialog, popup, confirmation, alert, or toast patterns.

Record domain events and dispatch to inbox handlers for side effects, audit trails, and activity feeds. Use when building activity logs, syncing external services, or decoupling event creation from processing. Triggers on event recording, audit trails, activity feeds, or inbox patterns.

Build production-quality Ruby gems. Use when creating new gems, structuring gem architecture, implementing configuration patterns, setting up testing, or preparing for publishing. Covers all gem types - libraries, CLI tools, Rails engines, and API clients.

Use proactively for GraphQL API design, schema optimization, or N+1 query issues. Designs schemas, resolvers, and subscriptions using graphql-ruby patterns.

Use when implementing Hotwire features with Turbo Drive, Turbo Frames, and Turbo Streams. Applies Rails 8 conventions, morphing, broadcasts, lazy loading, and real-time update patterns.

Build modern SPAs with Inertia.js and Rails using React, Vue, or Svelte. Use when creating Inertia pages, handling forms with useForm, managing shared props, or implementing client-side routing. Triggers on Inertia.js setup, SPA development, or React/Vue/Svelte with Rails.

Design Rails applications using layered architecture. Use when analyzing codebases for architecture violations, planning feature implementations, deciding where code belongs, or extracting abstractions from fat models/controllers. Complements dhh-rails-style (which keeps things simple) with guidance for when complexity demands structure.

This skill guides configuring Litestream for continuous SQLite backup in Rails 8+ apps. Use when setting up production backups for SQLite databases (Solid Queue, Solid Cache, Solid Cable).

Implement MCP server authentication with OAuth Dynamic Client Registration (RFC 7591), Authorization Server Metadata Discovery (RFC 8414), and per-agent credential support. Use when building admin UIs that let users connect to third-party MCP servers using OAuth (Linear, Sentry, Granola), bearer tokens (Render, custom APIs), or API keys. Covers metadata discovery, client registration, PKCE authorization, token exchange, token refresh, tool sync, and credential storage patterns.

Write Minitest tests for Ruby and Rails applications. Use when creating test files, writing test cases, or testing new features. Covers both traditional and spec styles, fixtures, mocking, and Rails integration testing patterns.

Review Rails code for query, memory, locking, and throughput problems before they become production incidents.

Review PII handling, encryption, and GDPR/CCPA compliance in Rails applications.

Use when adding polymorphic activity timelines with live Turbo Stream updates to any Rails model. Covers migration, model, concern, shared partials, broadcasting, and optional AI-generated change summaries. Triggers on activity feed, audit trail, timeline, field change tracking, or Turbo Stream broadcasting patterns.

Use when implementing Rails 8 built-in authentication, session management, admin sign-in, password reset, or protecting Rails controllers without Devise. Prefer Rails native auth generator and Minitest.

Review Ruby on Rails diffs, pull requests, patches, or staged changes for framework-specific correctness, regressions, security, data and deployment safety, performance, convention fit, and missing tests. Use whenever changed behavior runs inside a Rails application or engine.

Diagnose Rails errors, failing tests, and unexpected behavior by reproducing the issue, tracing the failing code path, and validating the smallest fix.

Run and fix Rails code-quality checks across Ruby, ERB, and security tooling. Use before pushing Rails changes, when CI reports RuboCop or ERB Lint violations, or when Brakeman reports security warnings.

Use proactively when refactoring Ruby on Rails code. Applies Rails conventions, Sandi Metz rules, and idiomatic Ruby patterns while maintaining test coverage.

This skill guides writing of new Ruby code following modern Ruby 3.x syntax, Sandi Metz's 4 Rules for Developers, and idiomatic Ruby best practices. Use when creating new Ruby files, writing Ruby methods, or refactoring Ruby code to ensure adherence to clarity, simplicity, and maintainability standards.

Final review for code simplicity. Identifies anti-patterns, code smells, and YAGNI violations.

Use when configuring or working with Solid Cache for database-backed caching. Applies Rails 8 conventions, cache key design, expiration strategies, database setup, and performance tuning patterns.

Use when configuring or working with Solid Queue for background jobs. Applies Rails 8 conventions, database-backed job processing, concurrency settings, recurring jobs, and production deployment patterns.

Use when creating or refactoring Stimulus controllers. Applies Hotwire conventions, controller design patterns, targets/values usage, action handling, and JavaScript best practices.

Wrap JSON-backed database columns with ActiveModel-like classes using store_model. Use when creating configuration objects, managing nested JSON attributes, or adding validations to JSON data. Triggers on JSON columns, store_model, typed JSON, configuration objects, or nested attributes.

Use when applying Tailwind CSS styling to Rails views. Uses utility classes, responsive design patterns, and integrates with Rails view helpers.

Build component-based UIs with ViewComponent and view_component-contrib. Use when creating reusable UI components, implementing slots and style variants, or building component previews. Triggers on ViewComponent creation, component patterns, Lookbook previews, or UI component architecture.