ai-context

Create expert-level Ruby on Rails generators for models, services, controllers, and full-stack features, plus application templates for whole-app setup. Use when building custom generators, scaffolds, code generation tools, or Rails application templates (rails new -m, app:template, starter-app automation, multi-tenant setup), or when the user mentions Rails generators, Thor DSL, or automated code generation.

A refactoring advisor grounded in Martin Fowler's "Refactoring: Improving the Design of Existing Code" (2nd edition). Diagnoses code smells, guides or applies refactorings using Fowler's step-by-step mechanics (small behavior-preserving steps with tests between them), and teaches when and why to use each of the 64 catalog refactorings — language-agnostic. Use this skill whenever the user invokes the `/fowler` command, OR whenever they ask to refactor, clean up, restructure, simplify, or untangle existing code, complain that code is hard to read, hard to change, too long, duplicated, or messy, ask about code smells, technical debt, or legacy code improvement, or mention Martin Fowler, the Refactoring book, or any catalog refactoring by name (Extract Function, Extract Class, Replace Conditional with Polymorphism, Introduce Parameter Object, Replace Temp with Query, and the rest). Trigger this even when the user doesn't say "refactor" or "fowler" explicitly but is wrestling with how to safely improve the structu

A specialized object-oriented design advisor channeling Sandi Metz's approach (from "Practical Object-Oriented Design in Ruby" and "99 Bottles of OOP"). Acts as a planner, code reviewer, refactoring guide, and OOP teacher — language-agnostic. Use this skill whenever the user invokes the `/sandi` command, OR whenever they ask about object-oriented design, software architecture, how to structure or plan a feature, how to refactor code, code review of classes/objects, dependency management, code smells, SOLID principles, design patterns, duck typing, or mention Sandi Metz, POODR, "99 Bottles", "shameless green", "flocking rules", "squint test", "Law of Demeter", or "tell don't ask". Trigger this even when the user doesn't say "Sandi" explicitly but is wrestling with how to design, structure, or improve OO code, plan a feature's architecture, or evaluate a PR's design.

Diagnose and fix slow RSpec test suites using TestProf and proven optimization techniques. Use this skill whenever the user mentions slow tests, test suite performance, RSpec speed, profiling specs, TestProf, TagProf, let_it_be, TPS profiler, or complains that their test suite takes too long. Also use it when the user sees high GC time in tests, wants to parallelize with test-queue, or asks which profiler to run against an RSpec suite. Prefer this skill over generic performance advice whenever RSpec is in the picture.

Comprehensive ESLint agent for JavaScript/TypeScript code quality. Use when setting up ESLint, configuring linting rules, analyzing code for issues, fixing violations, or integrating ESLint into development workflows. Triggers on requests involving code quality, linting, static analysis, or ESLint configuration for JavaScript, TypeScript, React, or Node.js projects.

Writing high-quality unit tests for JavaScript and TypeScript using Jest. Covers test structure (AAA pattern, USE naming), breaking dependencies (stubs, mocks, dependency injection), testing async code (promises, callbacks, timers), avoiding flaky tests, and test-driven development. Use when writing tests, debugging test failures, refactoring tests for maintainability, or questions about Jest, TDD, mocks, stubs, or test best practices.

Comprehensive Vitest testing framework guide with strong emphasis on Jest-to-Vitest migration. Covers automated migration using codemods, configuration setup, API differences, best practices, and troubleshooting. Use when migrating from Jest, setting up Vitest, writing tests, configuring test environments, or resolving migration issues. Primary focus is seamless Jest migration with minimal code changes.

Comprehensive guide for creating software diagrams using Mermaid syntax. Use when users need to create, visualize, or document software through diagrams including class diagrams (domain modeling, object-oriented design), sequence diagrams (application flows, API interactions, code execution), flowcharts (processes, algorithms, user journeys), entity relationship diagrams (database schemas), C4 architecture diagrams (system context, containers, components), state diagrams, git graphs, pie charts, gantt charts, or any other diagram type. Triggers include requests to "diagram", "visualize", "model", "map out", "show the flow", or when explaining system architecture, database design, code structure, or user/application flows.

Deploy containerized web applications to any Linux server using Kamal 2. Use when users need to deploy, configure, debug, or manage Kamal deployments including initial setup, configuration of deploy.yml, deployment workflows, rollbacks, managing accessories (databases, Redis, Litestream), troubleshooting deployment issues, CI/CD integration, multi-environment setups, or understanding Kamal commands and best practices. Also use when working with Kamal Proxy, Docker-based deployments, zero-downtime deploys, or 37signals deployment tooling.

Create, evaluate, and optimize GitHub Actions workflows and custom actions. Use when building CI/CD pipelines, creating workflow files, developing custom actions, troubleshooting workflow failures, performing security analysis, optimizing performance, or reviewing GitHub Actions best practices. Covers Ruby/Rails, TypeScript/Node.js, Heroku and Fly.io deployments.

Comprehensive Tailscale VPN setup, configuration, and management for mesh networking, secure access, and zero-trust infrastructure. Covers installation, CLI commands, subnet routers, exit nodes, Tailscale SSH, ACL/grants configuration, MagicDNS, Tailscale Serve/Funnel, API automation, and production deployment best practices. Use when setting up Tailscale, configuring tailnet access controls, deploying subnet routers or exit nodes, enabling Tailscale SSH, exposing services with Serve/Funnel, automating via the Tailscale API, troubleshooting connectivity, or planning production Tailscale deployments.

BDD testing with Cucumber and Gherkin for Ruby and Rails applications. Use when writing feature files (.feature), step definitions, hooks, or implementing Behaviour-Driven Development in Ruby/Rails projects. Covers Gherkin keywords (Feature, Scenario, Given/When/Then, Background, Scenario Outline, Rule), Ruby step definition patterns, Cucumber Expressions, hooks (Before/After/BeforeAll/AfterAll), tags, data tables, doc strings, World modules, and Capybara integration. Triggers on cucumber, gherkin, BDD, feature files, step definitions, acceptance testing, executable specifications.

Integrate RubyCritic to analyze Ruby code quality and maintain high standards throughout development. Use when working on Ruby projects to check code smells, complexity, and duplication. Triggers include creating/editing Ruby files, refactoring code, reviewing code quality, or when user requests code analysis or quality checks.

Comprehensive PostgreSQL configuration and usage analysis for Rails applications. Use when Claude Code needs to analyze a Rails codebase for database performance issues, optimization opportunities, or best practice violations. Detects N+1 queries, missing indexes, suboptimal database configurations, anti-patterns, and provides actionable recommendations. Ideal for performance audits, optimization tasks, or when users ask to "analyze the database", "check for N+1 queries", "optimize PostgreSQL", "review database performance", or "suggest database improvements".

Comprehensive Ruby and Rails code review using Sandi Metz rules and SOLID principles. Analyzes changed files in current branch vs base branch, runs rubycritic and simplecov, identifies OOP violations, Rails anti-patterns, security issues, code smells, and test coverage gaps. Outputs REVIEW.md with VSCode-compatible file links. Use when reviewing Ruby/Rails code, conducting code reviews, checking for design issues, pull request review, code quality analysis, or when user mentions Sandi Metz, POODR, 99 Bottles, SOLID, Law of Demeter, or "Tell Don't Ask".

Comprehensive Ruby on Rails v8.1 development guide with detailed documentation for Active Record, controllers, views, routing, testing, jobs, mailers, and more. Use when working on Rails applications, building Rails features, debugging Rails code, writing migrations, setting up associations, configuring Rails apps, or answering questions about Rails best practices and patterns.

Comprehensive RSpec testing for Ruby and Rails applications. Covers model specs, request specs, system specs, factories, mocks, and TDD workflow. Automatically triggers on RSpec-related keywords and testing scenarios.

Comprehensive test coverage analysis and improvement for Ruby and Rails applications using SimpleCov and SimpleCov Console formatter. Automatically runs coverage reports, identifies gaps, suggests tests, and enforces coverage standards. Integrates with RubyCritic for holistic code quality. Use when running tests, analyzing coverage, improving test suites, or setting up coverage tracking in Ruby/Rails projects.

Ruby language conventions, idioms, and modern features (3.x+) for writing idiomatic Ruby code. Covers error handling patterns, performance optimization, and Ruby-specific idioms. Use when writing or reviewing pure Ruby code, using modern Ruby features (pattern matching, ractors, RBS), optimizing Ruby performance, or establishing Ruby conventions. For Rails-specific guidance use the rails skill. For design patterns use design-patterns-ruby. For testing use rspec. For code style use rubocop.

Comprehensive Ruby implementations of Gang of Four (GoF) design patterns. Use when implementing object-oriented design solutions, refactoring to reduce coupling, solving architecture problems, or when user mentions specific patterns (Factory, Singleton, Observer, Strategy, etc.) in Ruby context.

Static analysis security vulnerability scanner for Ruby on Rails applications. Use when analyzing Rails code for security issues, running security audits, reviewing code for vulnerabilities, setting up security scanning in CI/CD, managing security warnings, or investigating specific vulnerability types (SQL injection, XSS, command injection, etc.). Also use when configuring Brakeman, reducing false positives, or integrating with automated workflows.

Ruby static code analyzer and formatter for enforcing style guidelines, detecting bugs, and improving code quality. Supports Rails, RSpec, and Performance extensions with safe autocorrection capabilities.