Skill Claude CodeCodex
Use when building command-line interface tools; when choosing argument parsing libraries; when handling stdin/stdout/stderr patterns; when implementing subcommands; when tests for CLI apps fail or are missing.
Skill Claude CodeCodex
Use when building MCP servers in TypeScript, Python, or C#; when implementing tools, resources, or prompts; when configuring Streamable HTTP transport; when migrating from SSE; when adding OAuth authentication; when seeing MCP protocol errors.
Skill Claude CodeCodex
Use when building interactive terminal dashboards or full-screen terminal applications; when implementing keyboard navigation, live data updates, or multi-panel layouts; when TUI is flickering, slow, or unresponsive; when handling terminal resize events.
Skill Claude CodeCodex
Matthew Hagrelius's deep code review process — a staff-level review emphasizing maintainability, reliability in distributed flows, observability, side-effect isolation, foreseeable failure scenarios, understandability, and test quality. Calibrates severity to project maturity (sprint-2 vs pre-GA vs mature prod) so the…
Skill Claude CodeCodex
Use when user requests research requiring multiple sources, comprehensive analysis, or synthesis across topics - technical research, domain knowledge gathering, market analysis, or learning about complex subjects.
Skill Claude CodeCodex
Enforce a precise, minimal design system inspired by Linear, Notion, and Stripe. Use this skill when building dashboards, admin interfaces, or any UI that needs Jony Ive-level precision - clean, modern, minimalist with taste. Every pixel matters.
Skill Claude CodeCodex
Use for every user-visible change in a GNOME app, new or existing, whether or not the request uses design vocabulary. Trigger on the repo rather than the wording — if it depends on gtk4/libadwaita (or is a GNOME-targeted Qt/PySide6 app), anything a user can see or interact with goes through this skill, including…
Skill Claude CodeCodex
Use for any change to a GTK 4/libadwaita app, new or existing, whether or not the request mentions GTK. Trigger on the repo rather than the wording — if Cargo.toml depends on gtk4/libadwaita, or sources import gi/Gtk (Python) or use Gtk (Vala), this applies to every change to that app, including requests phrased…
Skill Claude CodeCodex
Use when building .NET 10 or C# 14 applications; when using minimal APIs, modular monolith patterns, or feature folders; when implementing HTTP resilience, Options pattern, Channels, or validation; when seeing outdated patterns like old extension method syntax.
Skill Claude CodeCodex
The user's standards for writing tests, validating input and handling secrets, and writing C#/.NET. Use when writing or reviewing tests, deciding what to assert, validating input at a boundary, logging, or working in a C#/.NET codebase.
Skill Claude CodeCodex
Use when searching for concepts, ideas, or similar content without exact keywords; when user asks "find similar to...", needs semantic discovery, research across perspectives, or explicitly mentions exa.
Skill Claude CodeCodex
Use when writing, debugging, or reviewing Playwright tests for web apps; before writing test code; when tests are flaky, slow, or brittle; when seeing timeout errors, element not found, or race conditions; when using getByRole, locators, or assertions.
Skill Claude CodeCodex
Use when working with Python code and pyright-lsp plugin is enabled - for finding references, checking types, navigating definitions, or verifying type correctness.
Skill Claude CodeCodex
Use when working with TypeScript or JavaScript code and typescript-lsp plugin is enabled - for finding references, checking types, navigating definitions, or verifying type correctness.
Skill Claude CodeCodex
React and Next.js performance optimization guidelines from Vercel Engineering. This skill should be used when writing, reviewing, or refactoring React/Next.js code to ensure optimal performance patterns. Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance…
Skill Claude CodeCodex
Review UI code for Web Interface Guidelines compliance. Use when asked to "review my UI", "check accessibility", "audit design", "review UX", or "check my site against best practices".
Skill Claude CodeCodex
Use when building distributed apps with Aspire; orchestrating .NET, JavaScript, Python, or polyglot services; when environment variables or service discovery aren't working; when migrating from .NET Aspire 9 to 13+ or Community Toolkit; when seeing AddNpmApp deprecated errors; when OTEL not appearing in dashboard…
Skill Claude CodeCodex
Use when building AI agents with Microsoft Agent Framework (Semantic Kernel + AutoGen unified); when implementing memory or context providers; when threads won't deserialize; when workflow checkpointing fails; when migrating from Semantic Kernel or AutoGen; when seeing ChatAgent or AgentThread errors.
Skill Claude CodeCodex
Use when user asks about YouTube video content, wants to know what a video says, needs information from a YouTube URL, or when video transcription would answer their question.