Analyze and map code structure, data flow, and dependencies in legacy codebases. Use for understanding call stacks, dependency trees, side effects, risk profiles, and generating Mermaid diagrams. Ideal for legacy codebases with zero tests.

Detect and refactor code duplication with PMD CPD. TRIGGERS - code clones, DRY violations, duplicate code.

Guide for code conventions and formatting

Multi-language code coverage analysis, reporting, and quality gate enforcement

Standardized, hypothesis-driven debug investigation workflow for unexpected behavior, regressions, incidents, flaky tests, or production issues. Use to plan instrumentation, reproduce with decisive signals, compare runs, and narrow root cause without assuming any vendor or infrastructure.

Systematic debugging with root cause tracing. Use when encountering bugs, test failures, or unexpected behavior - find root cause before attempting fixes, trace backward through call chain.

You are a code education expert specializing in explaining complex code through clear narratives, visual diagrams, and step-by-step breakdowns. Transform difficult concepts into understandable explanations.

Generate detailed code explanations with visual diagrams and step-by-step breakdowns

Use when explaining code, concepts, or system behavior to a specific audience level - provides a structured explanation workflow with depth control and validation steps.

Use when asked to trace existing codepaths or explicitly asked to run the code-explorer subagent.

Use when generating boilerplate code, __init__.py files, or test scaffolds. Provides scripts that generate consistent, convention-following code.

code-guru

Language-specific coding guidelines. Use when implementing code in Python or other supported languages.

This skill should be used when the user asks to 'implement', 'write code', 'build a feature', 'create a function', 'add functionality', 'code this', 'make this work', or needs to write production code for Java/Spring Boot or TypeScript/Next.js following FP, DDD, and testability patterns. Ensures code follows functional core/imperative shell, proper invariants, Either-based error handling, and is designed for testing without mocks.

Migrate legacy code to modern frameworks, languages, and patterns with automated refactoring and testing

Write minimum necessary code following YAGNI principle to prevent bloat and over-engineering. Use when implementing features to keep the codebase lean and avoid premature optimization or speculative features.

Use the VSCode CLI to open files at specific line and column positions when explaining code, debugging, pointing to TODOs, or guiding users to specific locations in files. Automatically invoked when Claude needs to show users exactly where in a file to look.

Refactor code for better organization, cleaner architecture, and improved maintainability. Use for reorganizing file structures, splitting large components, updating imports after moves, and enforcing consistent patterns across the codebase.

You are a code refactoring expert specializing in clean code principles, SOLID design patterns, and modern software engineering best practices. Analyze and refactor the provided code to improve its quality, maintainability, and performance.

Run code snippets in 30+ programming languages including JavaScript, Python, TypeScript, Java, C, C++, Go, Rust, Ruby, PHP, and more. Use when the user wants to execute code, test algorithms, verify output, run scripts, or check code behavior. Supports both interpreted and compiled languages.

Delegates codebase searches to a lightweight agent. Use when searching for existing implementations, classes, or functions without loading search results into context.

Use when asked to simplify recently changed code without changing behavior or explicitly asked to run the code-simplifier subagent.

Analyze codebase with tokei (fast line counts by language) and difft (semantic AST-aware diffs). Get quick project overview without manual counting. Triggers on: how big is codebase, count lines of code, what languages, show semantic diff, compare files, code statistics.

Extract file structure (functions, classes, exports) efficiently without reading entire files, using ast-grep, go doc, ctags, or other language-specific tools to get outlines and signatures

PHP coding standards and WordPress patterns for ActivityPub plugin. Use when writing PHP code, creating classes, implementing WordPress hooks, or structuring plugin files.

Maintain and organize a curated library of code templates, boilerplate, and scaffolds for rapid project initialization

Enforce test-driven development (RED-GREEN-REFACTOR). Use when implementing features, fixing bugs, or changing behavior - write failing test first, then minimal code to pass.

QA engineer and test automation specialist with deep expertise in Flutter testing. Use for designing test strategies, writing unit/widget/integration tests, improving test coverage, and ensuring code reliability.

Transfer code between files with line-based precision. Use when users request copying code from one location to another, moving functions or classes between files, extracting code blocks, or inserting code at specific line numbers.

Validate code examples across the 4-Layer Teaching Method with intelligent strategy selection. Use when validating Python/Node/Rust code in book chapters. NOT for production deployment testing.

Use this when user wants you to walk through (code or text) files in a EDITOR to either explain how some code works, or to show the user what changes you made, etc. You would typically use this repeatedly to show the user your changes or code files one by one, sometimes with specific line-numbers. This way the user is easily able to follow along in their favorite EDITOR as you point at various files possibly at specific line numbers within those files.

Fase 3 - Implementation Protocol. Le Spec.md, solicita arquivos originais, aplica mudancas CIRURGICAS linha por linha, valida multi-tenant, testa e documenta. Preserva logica, zero improviso.

Analyze implementation details, trace data flow, and explain technical workings with precise file:line references. Use when you need to understand HOW code works.

Analyze a GitHub codebase to create comprehensive architecture documentation including ASCII diagrams, component relationships, data flow, hosting infrastructure, and file structure assessment.

You are a code refactoring expert specializing in clean code principles, SOLID design patterns, and modern software engineering best practices. Analyze and refactor the provided code to improve its quality, maintainability, and performance.

Expert in codebase archaeology and documentation retrieval. Use this when starting new project phases, refactoring large modules, or integrating new frameworks.

Deep codebase exploration using semantic search and relationship mapping. Use when you need to understand the current codebase.

Unified dead code detection, AST-based duplicate detection, and cleanup tool combining Legacy Tech Remover + Comprehensive Auditor + Architectural Cleanup with Knip, depcheck, TypeScript, Vue-specific analysis, file size/token limit detection, and AST-powered refactoring suggestions. Use for dead code, duplicates, oversized files, and architectural issues.

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Mandatory inspection before writing any Rails code. Use when: (1) Starting ANY implementation task, (2) Making architectural decisions, (3) Suggesting patterns or conventions, (4) Creating new files/classes. Core rule: Never plan without file path citations. Trigger keywords: analyze, inspect, patterns, conventions, codebase, discover, structure, dependencies, existing, before

Codebase organization for pikru. Use when you need to find where specific functionality lives.

Find and document file locations in the codebase. Use when you need to locate implementation files, tests, configurations, or any code artifacts by feature or topic.

Explores codebase and writes structured analysis documents. Spawned by map-codebase with a focus area.

Navigate, search, and understand project structures. Use when onboarding to a codebase, locating implementations, tracing dependencies, or understanding architecture. Provides patterns for file searching with Glob, code searching with Grep, and systematic architecture analysis.

Monitor and refactor large files into smaller, AI-friendly modules. Use when user asks to check file sizes, split large files, or organize the codebase. Ensures tests pass before and after refactoring.

Comprehensive pre-merge testing for CodeGeass. Tests PR changes FIRST, then runs regression tests on all CLI commands and Dashboard API endpoints.

Implement new features using TDD starting from README + Issue (following codegen-test), aligning with existing implementation conventions, and leveraging Serena MCP semantic search/editing to deliver high performance while being mindful of data races.

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