Git & Version Control

Systematic API design methodology with 6 validated patterns covering parameter categorization, safe refactoring, audit-first approach, automated validation, quality gates, and example-driven documentation. Use when designing new APIs, improving API consistency, implementing breaking change policies, or building API quality enforcement. Provides deterministic decision trees (5-tier parameter system), validation tool architecture, pre-commit hook patterns. Validated with 82.5% cross-domain transferability, 37.5% efficiency gains through audit-first refactoring.

Apply Grey Haven Studio's TypeScript/React and Python/FastAPI coding standards from production templates. Use when writing code, reviewing PRs, fixing linting errors, formatting files, or when the user mentions 'code standards', 'Grey Haven style', 'linting', 'Prettier', 'ESLint', 'Ruff', 'formatting rules', or 'coding conventions'. Includes exact Prettier/ESLint/Ruff configs, naming conventions, project structure, and multi-tenant database patterns.

Deploy TanStack Start applications to Cloudflare Workers/Pages with GitHub Actions, Doppler, Wrangler, database migrations, and rollback procedures. Use when deploying Grey Haven applications.

Grey Haven's comprehensive testing strategy - Vitest unit/integration/e2e for TypeScript, pytest markers for Python, >80% coverage requirement, fixture patterns, and Doppler for test environments. Use when writing tests, setting up test infrastructure, running tests, debugging test failures, improving coverage, configuring CI/CD, or when user mentions 'test', 'testing', 'pytest', 'vitest', 'coverage', 'TDD', 'test-driven development', 'unit test', 'integration test', 'e2e', 'end-to-end', 'test fixtures', 'mocking', 'test setup', 'CI testing'.

Use when sending emails - ActionMailer with async delivery via SolidQueue, templates, previews, and testing

Advanced MCP skill demonstrating multi-tool orchestration with git repository analysis

Generates and updates the latest app changelog based on git history since the last version tag.

Creates git commits following team's version control guidelines. Use when the user asks to "commit changes", "create a commit", "make a commit", "커밋해줘", "변경사항 저장", "커밋 메시지 작성", "커밋 만들어줘", or needs to commit staged/unstaged changes to git.

Comprehensive CI/CD pipeline methodology with quality gates, release automation, smoke testing, observability, and performance tracking. Use when setting up CI/CD from scratch, build time over 5 minutes, no automated quality gates, manual release process, lack of pipeline observability, or broken releases reaching production. Provides 5 quality gate categories (coverage threshold 75-80%, lint blocking, CHANGELOG validation, build verification, test pass rate), release automation with conventional commits and automatic CHANGELOG generation, 25 smoke tests across execution/consistency/structure categories, CI observability with metrics tracking and regression detection, performance optimization including native-only testing for Go cross-compilation. Validated in meta-cc with 91.7% pattern validation rate (11/12 patterns), 2.5-3.5x estimated speedup, GitHub Actions native with 70-80% transferability to GitLab CI and Jenkins.

Master 26 documented prompt engineering principles for crafting effective LLM prompts with 400%+ quality improvement. Includes templates, anti-patterns, and quality checklists for technical, learning, creative, and research tasks. Use when writing prompts for LLMs, improving AI response quality, training on prompting, designing agent instructions, or when user mentions 'prompt engineering', 'better prompts', 'LLM quality', 'prompt templates', 'AI prompts', 'prompt principles', or 'prompt optimization'.

Analyze git history for hotspots, coupling, and knowledge distribution. Use when user asks "who knows this code", "what files change most", "hotspots", "bus factor", "knowledge silos", or needs to understand code evolution.

Grey Haven's Linear issue workflow - creating well-documented issues, proper branch naming from issue IDs, commit message integration, PR linking, and status management. Use when creating issues, starting work, or managing project workflow.

Systematic methodology for constructing compact (<150 lines), expressive, Claude Code-integrated subagent prompts using lambda contracts and symbolic logic. Use when creating new specialized subagents for Claude Code with agent composition, MCP tool integration, or skill references. Validated with phase-planner-executor (V_instance=0.895).

Comprehensive documentation systems design including structure, generation, maintenance, and automation. Use when designing documentation systems, automating documentation generation, or managing large-scale documentation projects.

Format commit messages according to Grey Haven Studio's actual commitlint configuration (100 char header, lowercase subject, conventional commits). Use when creating git commits or reviewing commit messages.

TypeScript/JavaScript Test-Driven Development with Vitest, strict red-green-refactor methodology, React component testing, and comprehensive coverage patterns. Use when implementing TypeScript features with TDD, writing Vitest tests, testing React components, developing with test-first approach, or when user mentions 'TypeScript TDD', 'Vitest', 'React testing', 'JavaScript TDD', 'red-green-refactor', 'TypeScript unit tests', or 'test-driven TypeScript'.

Generate pull request descriptions following Grey Haven Studio standards with clear summary, motivation, implementation details, testing strategy, and comprehensive checklist. Use when creating or reviewing pull requests.

Add a new third-party dependency to the project following the version catalog and approval workflow.

Design effective MCP tools and Claude Code integrations using the consolidation principle. Fewer, better-designed tools dramatically improve agent success rates. Use when creating MCP servers, designing tool interfaces, optimizing tool sets, or when user mentions 'tool design', 'MCP', 'fewer tools', 'tool consolidation', 'tool architecture', or 'tool optimization'.

Apply Grey Haven database conventions - snake_case fields, multi-tenant with tenant_id and RLS, proper indexing, migrations for Drizzle (TypeScript) and SQLModel (Python). Use when designing schemas, writing database code, creating migrations, setting up RLS policies, or when user mentions 'database', 'schema', 'Drizzle', 'SQLModel', 'migration', 'RLS', 'tenant_id', 'snake_case', 'indexes', or 'foreign keys'.