Four-phase debugging framework that ensures root cause investigation before attempting fixes. Never jump to solutions. Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

Use when optimizing Tailwind CSS for production, reducing bundle size, and improving performance. Covers PurgeCSS, JIT mode, and build optimization.

Use when vitest configuration, Vite integration, workspace setup, and test environment configuration for modern testing.

Use when erlang's concurrency model including lightweight processes, message passing, process links and monitors, error handling patterns, selective receive, and building massively concurrent systems on the BEAM VM.

Use when configuring Docker environments for act, selecting runner images, managing container resources, or troubleshooting Docker-related issues with local GitHub Actions testing.

Use when creating or modifying GitHub Actions workflow files. Provides guidance on workflow syntax, triggers, jobs, steps, and expressions for creating valid GitHub Actions workflows that can be tested locally with act.

Use when building Android UIs with Jetpack Compose, managing state with remember/mutableStateOf, or implementing declarative UI patterns.

Core BDD concepts, philosophy, and the Three Amigos practice

TanStack Start full-stack React framework with Bun runtime. Use for TanStack Router, server functions, vinxi, or encountering SSR, build, preset errors.

Use when creating or modifying CocoaPods podspec files. Covers required attributes, file patterns, dependencies, and platform specifications for iOS, macOS, tvOS, watchOS, and visionOS projects.

Use when publishing CocoaPods libraries to CocoaPods Trunk. Covers pod trunk registration, podspec validation, version management, and publishing best practices for successful library distribution.

Cucumber best practices, patterns, and anti-patterns

Use when Elixir pattern matching including function clauses, case statements, with statements, and destructuring. Use for elegant control flow.

Use when configuring Expo apps with app.json, app.config.js, and EAS configuration. Covers app metadata, plugins, build configuration, and environment variables.

Use when configuring Fnox secrets management with fnox.toml. Covers file structure, secrets definition, profiles, and hierarchical configurations.

Use when setting up GraphQL Inspector in CI/CD pipelines, GitHub Actions, or GitLab CI for automated schema validation.

Use when implementing async/await, Task management, actors, or Combine reactive patterns in iOS applications.

Use when building iOS apps with UIKit, implementing MVVM/MVC/Coordinator patterns, or integrating UIKit with SwiftUI.

Multi-agent code review with confidence-based filtering

Use when working with Ruby gems, Bundler for dependency management, creating gemspecs, and publishing gems to RubyGems.

Use when formatting shell scripts with shfmt. Covers consistent formatting patterns, shell dialect support, common issues, and editor integration.

Use during implementation when designing modules, functions, and components requiring SOLID principles for maintainable, flexible architecture.

Use when writing or creating new Standard Operating Procedures (SOPs) for AI agents. Covers effective SOP writing, clarity principles, and actionable instruction design.

Use when configuring interactive controls and args for Storybook stories. Helps create dynamic, explorable component demonstrations with proper type constraints.

Use when working with Tailwind CSS utility classes for layout, spacing, typography, colors, and visual effects. Covers utility-first CSS patterns and class composition.

Use when testing GitHub Actions workflows locally with act. Covers act CLI usage, Docker configuration, debugging workflows, and troubleshooting common issues when running workflows on your local machine.

Master REST and GraphQL API design principles to build intuitive, scalable, and maintainable APIs that delight developers. Use when designing new APIs, reviewing API specifications, or establishing API design standards.

Use when biome configuration including biome.json setup, schema versions, VCS integration, and project organization.

Use when bundling JavaScript/TypeScript code with Bun's fast bundler. Covers building for different targets, tree-shaking, code splitting, and optimization strategies.

This skill should be used when the user asks about "bun:ffi", "foreign function interface", "calling C from Bun", "native libraries", "dlopen", "shared libraries", "calling native code", or integrating C/C++ libraries with Bun.

Use when implementing hot reloading with Bun (--hot, --watch), HMR, or automatic code reloading during development. Covers watch mode, hot mode, and HTTP server reload.

Evaluate JavaScript at bundle time and inline results. Use when optimizing compile-time code generation, embedding files, inlining environment variables, or executing code during the bundling process.

This skill should be used when the user asks about "Next.js with Bun", "Bun and Next", "running Next.js on Bun", "Next.js development with Bun", "create-next-app with Bun", or building Next.js applications using Bun as the runtime.

Use when building server-rendered React with Bun, including streaming SSR, hydration, renderToString, or custom SSR without a framework.

Use for bun:sqlite, SQLite operations, prepared statements, transactions, and queries.

Use when writing tests with Bun's built-in test runner. Covers test organization, assertions, mocking, and snapshot testing using Bun's fast test infrastructure.

This skill should be used when the user asks about "WebSocket in Bun", "real-time communication", "Bun.serve websocket", "ws server", "socket connections", "pub/sub", "broadcasting messages", "WebSocket upgrade", or building real-time applications with Bun.

Use when working with Crystal language development including WebSocket communication, TLS/SSL configuration, HTTP frameworks, ORM operations, and high-performance concurrent systems.

Use when Elixir Ecto patterns including schemas, changesets, queries, and transactions. Use when building database-driven Elixir applications.

Explain code, concepts, or technical decisions in clear, understandable terms

Use when configuring Fnox providers for encryption and secret storage. Covers age encryption, cloud providers (AWS, Azure, GCP), and password managers.

Use when implementing secure secrets management with Fnox. Covers encryption, key management, access control, and security hardening.

Use when validating GraphQL operations/documents against a schema, checking query depth, complexity, or fragment usage.

Use when managing environment variables and project settings with Mise. Covers env configuration, direnv replacement, and per-directory settings.

Use when defining and configuring Mise tasks in mise.toml. Covers task definitions, dependencies, file tasks, and parallel execution.

Use automatically during development workflows when making claims about tests, builds, verification, or code quality requiring concrete evidence to ensure trust through transparency.

Use when styling React Native Web components. Provides patterns for StyleSheet API, platform-specific styles, responsive design, and theming.

Use when working with Ruby blocks, procs, lambdas, and functional programming patterns including closures and higher-order functions.

Use when configuring shfmt for shell script formatting including .shfmt.toml setup, EditorConfig integration, and project-specific settings.

Use for Bun file I/O: Bun.file, Bun.write, streams, directories, glob patterns, metadata.

Use when building APIs with Hono framework on Bun, including routing, middleware, REST APIs, context handling, or web framework features.

Use when running Nuxt 3 with Bun runtime, building Vue/Nuxt apps with Bun, or configuring Nuxt projects to use Bun for development and production.

Use when managing dependencies with Bun's package manager. Covers installing packages, workspaces, lockfiles, and migrating from npm/yarn/pnpm to Bun.

Use when working with Redis in Bun (ioredis, Upstash), caching, pub/sub, session storage, or key-value operations.

Use when working with Bun's runtime APIs including file I/O, HTTP servers, and native APIs. Covers modern JavaScript/TypeScript execution in Bun's fast runtime environment.

Bun shell scripting with Bun.$, Bun.spawn, subprocess management. Use for shell commands, template literals, or command execution.

Use when building or running SvelteKit apps on Bun, including SSR, adapters, and Bun-specific APIs

Use for Web Workers in Bun, worker_threads, parallel processing, and background tasks.

Use when managing agent context, memory, and conversation state in Claude AI agents using the Agent SDK.

Use when configuring Credo static analysis for Elixir projects requiring customized code quality rules and settings.

Writing effective step definitions and organizing test code

Use when working with Expo SDK modules for camera, location, notifications, file system, and other device APIs. Covers permissions, configurations, and best practices.

Use when implementing file-based routing in Expo with Expo Router. Covers app directory structure, navigation, layouts, dynamic routes, and deep linking.

Use when discovering, exploring, or retrieving gluestack-ui components via MCP tools. Provides access to component source code, variants, demos, and metadata.

Use when auditing GraphQL operations for complexity metrics, depth analysis, directive usage, or query performance concerns.

Use when detecting breaking changes between GraphQL schema versions, comparing schemas across branches, or validating schema migrations.

Manage MCP servers - discover, analyze, execute tools/prompts/resources. Use for MCP integrations, capability discovery, tool filtering, programmatic execution, or encountering context bloat, server configuration, tool execution errors.

Use when managing development tool versions with Mise. Covers installing tools, version pinning, and replacing language-specific version managers.

Validate test effectiveness with mutation testing using Stryker (TypeScript/JavaScript with Vitest or bun test via @hughescr/stryker-bun-runner) and mutmut (Python). Find weak tests that pass despite code mutations. Use to improve test quality.

Use when working with Ruby's object-oriented programming features including classes, modules, inheritance, mixins, and method visibility.

Use when creating or modifying Storybook stories for components. Ensures stories follow CSF3 format, properly showcase component variations, and build successfully.

HTTP API testing for TypeScript (Supertest) and Python (httpx, pytest). Test REST APIs, GraphQL, request/response validation, authentication, and error handling.

Use when multiple fix attempts fail and you need to systematically restore to a working baseline and reimplement instead of fixing broken code.

Use when managing blueprints directory structure and avoiding duplication. Always search existing blueprints before creating to prevent duplicate documentation. Handles naming conventions and cross-references.

Use for Docker with Bun, Dockerfiles, oven/bun image, containerization, and deployments.

Use when integrating Drizzle ORM with Bun's SQLite driver for type-safe schema definitions and migrations.

Use when building HTTP servers with Bun.serve, handling requests/responses, implementing routing, creating REST APIs, or configuring fetch handlers.

Use when integrating tools, permissions, and MCP servers with Claude AI agents using the Agent SDK.

Use when managing Helm values files and configuration overrides for customizing Kubernetes deployments.

Idempotent API operations with idempotency keys, Redis caching, DB constraints. Use for payment systems, webhook retries, safe retries, or encountering duplicate processing, race conditions, key expiry errors.

Use when managing state and side effects in Ink applications using React hooks for terminal UIs.

Use when creating terminal layouts with Ink using Flexbox-based positioning and styling for CLI applications.

Use when building SwiftUI views, managing state with @State/@Binding/@ObservableObject, or implementing declarative UI patterns in iOS apps.

Use when writing technical documentation, READMEs, or project documentation in markdown. Covers structure, conventions, and best practices.

Use when working with React Native Web projects. Provides core concepts, components, and cross-platform patterns for building web applications with React Native.

Use when responding to production incidents following SRE principles and best practices.

Use when building reliable and scalable distributed systems.

Use when defining version policies, banning dependencies, pinning versions, or creating partitioned version groups in syncpack. Covers advanced version management patterns.

Use when creating or updating technical blueprint documentation for new features, API changes, or architectural modifications. Always search existing blueprints first to avoid duplication, then write with proper structure.

Use when migrating from Jest to Bun's test runner, import compatibility, mocks, and config.

Use for test lifecycle hooks: beforeAll, afterAll, beforeEach, afterEach, fixtures, preload.

Use for mock functions in Bun tests, spyOn, mock.module, implementations, and test doubles.

Use when defining and working with Ecto schemas including field types, associations, and embedded schemas. Use when modeling database entities in Elixir.

Use when building and deploying Expo apps with EAS Build. Covers build configuration, development builds, production builds, and app store submission.

Use when implementing over-the-air (OTA) updates with Expo Updates. Covers update configuration, checking for updates, and update strategies.

Generate Jest unit tests for JavaScript/TypeScript with mocking, coverage. Use for JS/TS modules, React components, test generation, or encountering missing coverage, improper mocking, test structure errors.