Development Claude Skills
8 676 development skills from 759 authors. They write and change code. Half of them fit into 1 830 tokens or less — that is what one costs your context window when the agent loads it. 1 213 ship runnable scripts rather than instructions alone. 42 of them cannot work without an MCP server, most often rube. We also found 1 172 copies of these same skills sitting in other people's repositories — counted once here, not 1 172 times.
8 676 unique 759 authors 5 252 updated this month 1 369 from vendors
Swift iOS architecture guidance and playbooks for MVVM, MVI, TCA, Clean Architecture, VIPER, MVP, Coordinator, and Reactive patterns. Use when designing, implementing, refactoring, or reviewing the architecture of a SwiftUI or UIKit feature, module, or codebase.
A live visual Kanban board and continuity layer for long-running agentic tasks. Nobody wants to read a markdown plan or stare at raw HTML while an agent grinds for an hour, so Plandeck turns the plan into a board that organizes itself. Use it when a task is multi-step, long-running, or needs visual planning. Break the work into cards, declare which card depends on which, and Plandeck computes the critical path, auto-promotes cards to Ready as their dependencies clear, rolls up story-point estimates into an honest percent complete, and names the one next action. Plans, observed transitions, and last-known-good snapshots stay as plain files on disk, so they survive /clear and context resets. After a reset, run plandeck next to recover the single next move and its recent history. If the plan stops parsing, run plandeck doctor before using git. Renders a live board in the browser over SSE. Triggers on plan a project, break down a task, kanban board, task board, visual plan, long-running agent, agentic task, track dependencies, critical path, story-point estimates, what is next, mission journal, recover plan, plandeck.
| Building robust R packages with modern tidyverse patterns. Use this skill when creating or maintaining R packages, designing APIs, choosing dependencies, implementing input validation, writing error messages, or deciding between internal and exported functions. Covers dependency strategy, tidyverse API design patterns, validation approaches, error handling with cli/rlang, testing levels, and documentation priorities.
| Tidy evaluation and programmatic tidyverse patterns using rlang. Use this skill when writing functions that accept column names as arguments, building tidyverse-compatible APIs, or working with data-masking and injection operators. Covers embracing with {{}}, injection (!! and !!!), dynamic dots, .data/.env pronouns, name injection with glue syntax, bridge patterns between selection and data-masking, and package development with rlang.
Use when reviewing or designing Gradle build structure for KMP projects — shared build logic, convention plugins, version catalogs, Android KMP plugin usage, source-set configuration, and module dependency hygiene.
Use when designing, reviewing, or refactoring module boundaries in KMP or Android projects — feature, data, app, and common modules, dependency direction, visibility control, and granularity.
| Build autonomous AI agents with Claude Agent SDK. TypeScript v0.2.141 | Python v0.2.82. structured outputs, and sessions. permissions/hooks, using structured outputs, troubleshooting SDK errors, or working with subagents.
This skill should be used when the user wants Claude Code to act purely as a manager/architect while Gemini CLI does all the coding work. Claude Code drives Gemini like an intern - issuing tasks, reviewing output, requesting fixes - but never writes code itself. Use when user says "manage gemini", "architect mode", "drive gemini", or wants to delegate all implementation to Gemini.
Guided tour of changes or codebase - explains how things work conceptually rather than listing changes mechanically. Use anytime you're asked to explain, review, walk through, or summarize work, branch changes, or codebase architecture.
>- Draft maintainer replies to GitHub PRs and issues in the user's voice. Use when the user asks to reply, respond, comment on, or review a PR/issue, or when drafting feedback for contributors. Handles approvals, change requests, closures, and issue triage. Copies result to clipboard.
Imagine future bug post-mortems for the codebase. Identifies fragile code, implicit assumptions, and likely failure modes by writing realistic incident reports for bugs that haven't happened yet.
Analyzes threads for friction points where the model struggled or user corrected it. Produces actionable improvements for AGENTS.md, skills, tools, and codebase. Use when asked to review a thread, do a postmortem, or analyze what went wrong.
Use when maintaining or checking boundaries of the Mathodology skills repository itself, or deciding whether a change belongs on this branch.
Use when a Mathodology workflow needs export/packaging/API reasoning, or when consulting archived knowledge about the former gateway and API subsystem.
SOLID principles, design patterns, DRY, KISS, and clean code fundamentals. Use when reviewing architecture, checking code quality, refactoring, or discussing design decisions. Triggers on "review architecture", "check code quality", "SOLID principles", "design patterns", or "clean code".
Laravel AI SDK for building AI-powered features. Use when creating agents, generating images or audio, working with embeddings, vector search, or testing AI features. Triggers on tasks involving laravel/ai, AI agents, tool-calling, structured output, streaming, embeddings, reranking, or AI faking in tests.
Laravel + Inertia.js + React integration patterns. Use when building Inertia page components, handling forms with useForm, managing shared data, or implementing persistent layouts. Triggers on tasks involving Inertia.js, page props, form handling, or Laravel React integration.
Git best practices, branching strategies, commit conventions, and PR workflows. Use when reviewing git history, writing commits, setting up branching strategy, or improving git practices. Triggers on "git best practices", "commit message", "branching strategy", or "PR workflow".
Detect AI-generated code patterns ("slop") in PHP/Laravel and TypeScript/React source — comment narration, generic naming, premature interfaces, defensive overdose, mock-everything tests, and the absence of human "scars". Use when reviewing AI-assisted PRs, auditing code for taste/quality (not metrics — that's technical-debt), or hardening a code-review checklist. Triggers on "review for AI slop", "find AI patterns", "check code feels human", "audit code-quality taste".
RESTful API design, error handling, versioning, and best practices. Use when designing APIs, reviewing endpoints, implementing error responses, or setting up API structure. Triggers on "design API", "review API", "REST best practices", or "API patterns".
React and Vite performance optimization guidelines. Use when writing, reviewing, or optimizing React components built with Vite. Triggers on tasks involving Vite configuration, build optimization, code splitting, lazy loading, HMR, bundle size, or React performance.
Project documentation lifecycle for PHP/Laravel and Node/TypeScript/React projects — bootstrapping essential docs, naming and folder conventions, freshness, and cleanup of AI-generated junk and stale files. Use when starting a new project, setting up docs/ structure, auditing markdown files, cleaning up the docs folder, or deciding which docs to keep, archive, or delete. Triggers on "set up docs", "audit docs", "clean up markdown", "what docs does this project need", "organize docs folder", "find stale docs".
React Query and Zustand patterns for state management. Use when implementing data fetching, caching, mutations, or client-side state. Triggers on tasks involving useQuery, useMutation, Zustand stores, caching, or state management.
TypeScript best practices for React development. Use when writing typed React components, hooks, events, refs, or generic components. Triggers on tasks involving TypeScript errors, type definitions, props typing, or type-safe React patterns.
Technical debt inventory, prioritization, and audit for PHP/Laravel (MySQL) and Node/TypeScript/React projects. Use when assessing code health, identifying refactoring candidates, planning debt paydown, or auditing a codebase for accumulated debt. Triggers on "audit technical debt", "find tech debt", "debt inventory", "what should we refactor first", or tasks involving code health, security debt, performance debt, data debt, observability debt, debt prioritization, or remediation planning.
Git Context Controller (GCC) v2 — Lean agent memory backed by real git. Stores hash + intent + optional decision notes instead of verbose markdown. Auto-bridges to aiyoucli vector memory when available. Dual mode: git-backed (lean index.yaml) or standalone (markdown fallback). Triggers on /gcc commands or natural language like 'commit this progress', 'branch to try an alternative', 'merge results', 'recover context'.
| When a user asks how long a task will take, requests a time estimate, or before starting any non-trivial coding task, immediately run scripts/estimate_task.py to analyze the codebase scope and provide a data-driven time estimate. Show the estimate breakdown, risk factors, and checkpoint recommendations without asking.
| Orchestration pattern for large-scale processing where work is distributed, processed independently, then combined. Map phase splits and processes, Reduce phase aggregates results. Use for codebase-wide analysis, bulk transformations, or any task where "do X to everything, then summarize."
IP networking fundamentals for Zephyr RTOS. Covers IoT protocol selection (LwM2M, CoAP, MQTT), IP stack configuration and trimming (IPv4/IPv6, UDP/TCP), and professional SDK integration as Zephyr modules using West manifests. Trigger when building cloud-connected applications, optimizing network memory usage, or integrating external cloud SDKs.
Integration of advanced IoT protocols for Zephyr RTOS. Covers OpenThread mesh networking, Matter-over-Thread device development, Golioth Cloud SDK patterns, and LoRaWAN basics. Trigger when building smart home devices, wide-area sensor networks, or cloud-integrated hardware fleets.
Automatically generate relationship and dependency maps for any component-based codebase (React, Vue, Svelte, Astro, Next.js, Angular, Solid). Auto-detects framework. Supports TOON format for 30-60% token savings. Use when indexing codebases, mapping component relationships, documenting dependencies, or understanding unfamiliar projects. Generates JSON/TOON files mapping component usage, imports, npm dependencies, utilities, CSS, and data queries.
Automatically generate relationship and dependency maps for any component-based codebase (React, Vue, Svelte, Astro, Next.js, Angular, Solid). Auto-detects framework. Supports TOON format for 30-60% token savings. Use when indexing codebases, mapping component relationships, documenting dependencies, or understanding unfamiliar projects. Generates JSON/TOON files mapping component usage, imports, npm dependencies, utilities, CSS, and data queries.
[AUTO-INVOKE] MUST be invoked BEFORE creating git commits, PRs, or code reviews. Covers Conventional Commits, PR templates, review requirements, and AI-assisted development rules. Trigger: any task involving git commit, git push, PR creation, or code review.
[AUTO-INVOKE] MUST be invoked BEFORE writing or modifying any Solidity contract (.sol files). Covers pragma version, naming conventions, project layout, OpenZeppelin library selection standards, oracle integration, and anti-patterns. Trigger: any task involving creating, editing, or reviewing .sol source files.
Design stable, compatible public APIs using extend-only design principles. Manage API compatibility, wire compatibility, and versioning for NuGet packages and distributed systems.
Write modern, high-performance C# code using records, pattern matching, value objects, async/await, Span<T>/Memory<T>, and best-practice API design patterns. Emphasizes functional-style programming with C# 12+ features.
Understand implementation details of .NET code by decompiling assemblies. Use when you want to see how a .NET API works internally, inspect NuGet package source, view framework implementation, or understand compiled .NET binaries.
Organize DI registrations using IServiceCollection extension methods. Group related services into composable Add* methods for clean Program.cs and reusable configuration in tests.
Modern .NET project structure including .slnx solution format, Directory.Build.props, central package management, SourceLink, version management with RELEASE_NOTES.md, and SDK pinning with global.json.
Scan Apple's SwiftUI documentation for deprecated APIs and update the SwiftUI Expert Skill with modern replacements. Use when asked to "update latest APIs", "refresh deprecated SwiftUI APIs", "check for new SwiftUI deprecations", "scan for API changes", or after a new iOS/Xcode release. Requires the Sosumi MCP to be available.
Backend architecture patterns, API design, database optimization, and server-side best practices for Hono, Cloudflare Workers, and Next.js Route Handlers.
Build and TypeScript error resolution specialist. Use PROACTIVELY when build fails or type errors occur. Fixes build/type errors only with minimal diffs, no architectural edits. Focuses on getting the build green quickly.
Universal coding standards, best practices, and patterns for TypeScript, JavaScript, React, and Node.js development.
Frontend development patterns for React, Next.js, state management, performance optimization, and UI best practices.
Use when researching Apple frameworks, APIs, or WWDC sessions - provides techniques for retrieving full transcripts, code samples, and documentation using Chrome browser and sosumi.ai
Use when ANY question involves Apple framework APIs, Swift compiler errors, or Xcode-bundled documentation. Covers Liquid Glass, Swift 6.2 concurrency, Foundation Models, SwiftData, StoreKit, 32 Swift compiler diagnostics.
Reference — AVFoundation audio APIs, AVAudioSession categories/modes, AVAudioEngine pipelines, bit-perfect DAC output, iOS 26+ spatial audio capture, ASAF/APAC, Audio Mix with Cinematic framework
Complete background task API reference - BGTaskScheduler, BGAppRefreshTask, BGProcessingTask, BGContinuedProcessingTask (iOS 26), beginBackgroundTask, background URLSession, with all WWDC code examples