Claude Skills
The open format is called Agent Skills and works in Claude Code, Codex, Cursor and other agents — most people know it as Claude Skills.
Every Agent Skill we could find on GitHub, deduplicated by content. 79 437 files from 1 744 authors, of which 61 785 are unique — the rest is the same skill repackaged into someone else's repository. For each one: what it weighs in tokens, whether it ships runnable scripts, and which MCP servers it needs.
Standards for Maven, Gradle, and static analysis in Java projects. Use when setting up Java build tooling, configuring Spotless or Checkstyle, managing JDK versions with sdkman, writing Dockerfiles for Java services, or adding SpotBugs/SonarLint. (triggers: pom.xml, build.gradle, build.gradle.kts, mvnw, gradlew, .sdkmanrc, spotbugs, checkstyle, spotless, eclipse-temurin)
Idiomatic JavaScript patterns and conventions for maintainable code. Use when writing or refactoring JavaScript following idiomatic patterns and conventions. (triggers: **/*.js, **/*.mjs, module, import, export, error, validation)
Modern JavaScript (ES2022+) patterns for clean, maintainable code. Use when working with modern JavaScript features like optional chaining, nullish coalescing, or ESM. (triggers: **/*.js, **/*.mjs, **/*.cjs, const, let, arrow, async, await, promise, destructuring, spread, class)
Development tools, linting, and testing for JavaScript projects. Use when configuring ESLint, Prettier, or test runners for JavaScript projects. (triggers: .eslintrc.*, jest.config.*, package.json, eslint, prettier, jest, test, lint, build)
Core patterns for robust Kotlin code including scope functions and backing properties. Use when writing idiomatic Kotlin, choosing between scope functions (let/apply/run/also/with), encapsulating mutable state with backing properties, or exposing read-only collection interfaces. (triggers: **/*.kt, apply, let, run, also, with, runCatching, backing property, MutableList, internal, private set)
Standards for safe, structured concurrency in Kotlin. Use when writing suspend functions, choosing coroutine scopes, handling cancellation in loops, selecting between StateFlow and SharedFlow, debugging coroutine leaks, or asked why GlobalScope is dangerous. (triggers: **/*.kt, suspend, CoroutineScope, launch, async, Flow, StateFlow, SharedFlow, viewModelScope, GlobalScope, Dispatchers, isActive, yield, runBlocking)
Idiomatic Kotlin 1.9+ standards including null safety, sealed classes, and expression syntax. Use when working with Kotlin null safety, data classes, sealed interfaces, extension functions, or migrating Java code to Kotlin. (triggers: **/*.kt, **/*.kts, val, var, ?., ?:, !!, data class, sealed, when, extension, lazy, lateinit, object)
Standards for Gradle Kotlin DSL, Version Catalogs, and MockK for Kotlin projects. Use when configuring build.gradle.kts, setting up libs.versions.toml, adding MockK for tests, or choosing between Kotlin-compatible test assertion libraries. (triggers: build.gradle.kts, libs.versions.toml, detekt.yml, mockk, kts, version catalog, kotest)
Modern TypeScript standards for type safety and maintainability. Use when working with types, interfaces, generics, enums, unions, or tsconfig settings.
REST and JSON API standards for modern Laravel backends. Use when designing REST endpoints, API resources, or JSON API responses in Laravel. (triggers: routes/api.php, app/Http/Resources/**/*.php, resource, collection, sanctum, passport, cors)
Core architectural standards for scalable Laravel applications. Use when structuring service layers, repositories, or scalable architecture in Laravel. (triggers: app/Http/Controllers/**/*.php, routes/*.php, controller, service, action, request, container)
Scalable asynchronous workflows using Queues, Jobs, and Events. Use when implementing queued jobs, event-driven workflows, or async processing in Laravel. (triggers: app/Jobs/**/*.php, app/Events/**/*.php, app/Listeners/**/*.php, ShouldQueue, dispatch, batch, chain, listener)
Expert patterns for DDD, DTOs, and Ports & Adapters in Laravel. Use when applying Domain-Driven Design, DTOs, or ports-and-adapters patterns in Laravel. (triggers: app/Domains/**/*.php, app/Providers/*.php, domain, dto, repository, contract, adapter)
Expert patterns for advanced queries, Redis caching, and database scalability. Use when optimizing Laravel queries, implementing Redis caching, or scaling databases. (triggers: config/database.php, database/migrations/*.php, join, aggregate, subquery, selectRaw, Cache)
Advanced Eloquent ORM patterns for performance and query reuse. Use when working with Eloquent relationships, scopes, or advanced query optimization in Laravel. (triggers: app/Models/**/*.php, scope, with, eager, chunk, model)
Security standards for hardening Laravel applications. Use when securing authentication, authorization, input validation, or CSRF in Laravel. (triggers: app/Policies/**/*.php, config/*.php, policy, gate, authorize, env, config)
Expert standards for session drivers, security headers, and middleware logic. Use when configuring session drivers, security headers, or custom middleware in Laravel. (triggers: app/Http/Middleware/**/*.php, config/session.php, session, driver, handle, headers, csrf)
Automated testing standards with Pest and PHPUnit. Use when writing Pest or PHPUnit feature/unit tests in Laravel applications. (triggers: tests/**/*.php, phpunit.xml, feature, unit, mock, factory, sqlite)
Ecosystem management, Artisan, and asset bundling. Use when managing Composer dependencies, Artisan commands, or Vite asset bundling in Laravel. (triggers: package.json, composer.json, vite.config.js, artisan, vite, horizon, pint, blade)
Response wrapping, pagination, and error standardization. Use when standardizing API response envelopes, pagination, or error formats in NestJS. (triggers: **/*.controller.ts, **/*.dto.ts, ApiResponse, Pagination, TransformInterceptor)
Standards for scalable, modular NestJS backend architecture. Use when designing module boundaries, feature modules, or scalable NestJS architecture. (triggers: **/*.module.ts, main.ts, NestFactory, Module, Controller, Injectable)
Standard workflow for BullMQ jobs in NestJS. Use for: queue processors, redis-throttler, Upstash limits, idle polling (10s), stalled jobs, and retention. Triggers on: bullmq, processors, registerQueue, drainDelay, stalledInterval, removeOnComplete, Redis outages, or failing background tasks. (triggers: **/*.processor.ts, **/*.module.ts, **/bull-queue.constants.ts, **/redis-throttler*.ts, queue, background job, worker, processor, bullmq, drainDelay, stalledInterval, removeOnComplete, redis limit, upstash, fail-open, throttler)
Multi-level caching, Invalidation patterns, and Stampede protection. Use when implementing multi-level caching or cache invalidation strategies in NestJS. (triggers: **/*.service.ts, **/*.interceptor.ts, CacheInterceptor, CacheTTL, Redis, stale-while-revalidate)
Environment variables validation and ConfigModule setup. Use when validating environment variables with Joi/Zod or configuring ConfigModule in NestJS. (triggers: .env, app.module.ts, **/config.ts, ConfigModule, Joi, env)
Controller/Service separation and Custom Decorators. Use when defining NestJS controllers, services, or custom parameter decorators. (triggers: **/*.controller.ts, **/*.service.ts, Controller, Injectable, ExecutionContext, createParamDecorator)
Data access patterns, Scaling, Migrations, and ORM selection. Use when implementing TypeORM/Prisma repositories, migrations, or database patterns in NestJS. (triggers: **/*.entity.ts, prisma/schema.prisma, TypeOrmModule, PrismaService, MongooseModule, Repository)
Docker builds, Memory tuning, and Graceful shutdown. Use when containerizing NestJS apps, tuning memory, or implementing graceful shutdown. (triggers: Dockerfile, k8s/**, helm/**, Dockerfile, max-old-space-size, shutdown hooks)
Swagger automation and Generic response documentation. Use when generating OpenAPI/Swagger documentation or documenting NestJS API responses. (triggers: main.ts, **/*.dto.ts, DocumentBuilder, SwaggerModule, ApiProperty, ApiResponse)
Global Exception Filters and standard error formats. Use when implementing global exception filters or standardizing error responses in NestJS. (triggers: **/*.filter.ts, main.ts, ExceptionFilter, Catch, HttpException)
Secure file handling, Validation, and S3 streaming. Use when implementing secure file uploads, validation, or S3 streaming in NestJS. (triggers: **/*.controller.ts, FileInterceptor, Multer, S3, UploadedFile)
Standards for Notification Types, Service Architecture, and FCM Integration. Use when building notification services or integrating FCM in NestJS. (triggers: notification.service.ts, notification.entity.ts, notification, push, fcm, alert, reminder)
Structured logging (Pino) and Prometheus metrics. Use when adding structured logging with Pino or Prometheus metrics to NestJS services. (triggers: main.ts, **/*.module.ts, nestjs-pino, Prometheus, Logger, reqId)
Fastify adapter, Scope management, and Compression. Use when optimizing NestJS performance with Fastify, request-scoped providers, or compression. (triggers: main.ts, FastifyAdapter, compression, SINGLETON, REQUEST scope)
WebSocket and SSE selection strategies and scaling. Use when implementing WebSocket gateways or Server-Sent Events in NestJS. (triggers: **/*.gateway.ts, **/*.controller.ts, WebSocketGateway, SubscribeMessage, Sse, Socket.io)
Distributed cron jobs and locking patterns. Use when implementing scheduled tasks or distributed locking patterns in NestJS. (triggers: **/*.service.ts, @Cron, CronExpression, ScheduleModule)
Elasticsearch integration and Sync patterns. Use when integrating Elasticsearch or implementing search index sync in NestJS. (triggers: **/*.service.ts, **/search/**, Elasticsearch, CQRS, Synchronization)
Standards for multi-tenant isolation and PostgreSQL Row Level Security. Use when enforcing tenant isolation or PostgreSQL RLS in NestJS multi-tenant apps. (triggers: src/modules/**, SECURITY.md, src/migrations/**, RLS, Row Level Security, childId, isolation, access policy)
Authentication, RBAC, and Hardening standards. Use when implementing JWT auth, RBAC guards, or security hardening in NestJS. (triggers: **/*.guard.ts, **/*.strategy.ts, **/auth/**, Passport, JWT, AuthGuard, CSRF, Helmet)
Unit and E2E testing with Jest, mocking strategies, and database isolation. Use when writing NestJS unit tests, E2E tests with supertest, or mock providers. (triggers: **/*.spec.ts, test/**/*.e2e-spec.ts, Test.createTestingModule, supertest, jest, beforeEach)
gRPC, RabbitMQ standards and Monorepo contracts. Use when implementing gRPC microservices, RabbitMQ messaging, or monorepo transport in NestJS. (triggers: main.ts, **/*.controller.ts, Transport.GRPC, Transport.RMQ, MicroserviceOptions)
File-system routing, Layouts, and Route Groups. Use when implementing App Router routing, nested layouts, or route groups in Next.js. (triggers: app/**/page.tsx, app/**/layout.tsx, app/**/loading.tsx, App Router, Layout, Route Group, parallel routes)
Scalable project structure using Feature-Sliced Design (FSD). Use when structuring a Next.js project with Feature-Sliced Design architecture. (triggers: src/features/**, src/entities/**, src/widgets/**, FSD, Feature Sliced Design, slices, segments)
Secure token storage (HttpOnly Cookies) and Middleware patterns. Use when implementing authentication, secure session storage, or auth middleware in Next.js. (triggers: middleware.ts, **/auth.ts, **/login/page.tsx, cookie, jwt, session, localstorage, auth)
The 4 layers of caching in Next.js. Use when configuring request memoization, data cache, full-route cache, or router cache in Next.js. (triggers: **/page.tsx, **/layout.tsx, **/action.ts, unstable_cache, revalidateTag, Router Cache, Data Cache)
Secure, reusable data access patterns with DTOs and Taint checks. Use when building a data access layer with DTOs and server-side taint checking in Next.js. (triggers: **/lib/data.ts, **/services/*.ts, **/dal/**, DAL, Data Access Layer, server-only, DTO)
Fetch API, Caching, and Revalidation strategies. Use when fetching data, configuring cache behavior, or implementing revalidation in Next.js. (triggers: **/*.tsx, **/service.ts, fetch, revalidate, no-store, force-cache)
Best practices for multi-language handling, locale routing, and detection strategies across App and Pages Router. Use when adding i18n, locale routing, or language detection in Next.js. (triggers: middleware.ts, app/[lang]/**, pages/[locale]/**, messages/*.json, next.config.js, i18n, locale, translation, next-intl, react-intl, next-translate)
Image, Font, Script, and Metadata optimization strategies. Use when optimizing Next.js images, fonts, scripts, or page metadata for performance. (triggers: **/layout.tsx, **/page.tsx, next/image, next/font, metadata, generateMetadata)
Legacy routing, getServerSideProps conventions, and strict architectural constraints. Use when working in a Pages Router project with getServerSideProps, getStaticProps, or _app in Next.js. (triggers: pages/**/*.tsx, pages/**/*.ts, Pages Router, getServerSideProps, getStaticProps, _app, useRouter)
SSG, SSR, ISR, Streaming, and Partial Prerendering (PPR). Use when choosing a rendering strategy (SSG, SSR, ISR, PPR, or Streaming) in Next.js. (triggers: **/page.tsx, **/layout.tsx, generateStaticParams, dynamic, dynamicParams, PPR, streaming)
Core security standards for App Router and Server Actions. Use when securing Next.js App Router routes, Server Actions, or API endpoints. (triggers: app/**/actions.ts, middleware.ts, action, boundary, sanitize, auth, jose)
Mutations, Form handling, and RPC-style calls. Use when implementing Server Actions, form mutations, or RPC-style data mutations in Next.js. (triggers: app/**/actions.ts, src/app/**/actions.ts, app/**/*.tsx, src/app/**/*.tsx, use server, Server Action, revalidatePath, useFormStatus)
RSC usage, ''use client'' directive, and Component Purity. Use when working with React Server Components or deciding where to place the ''use client'' boundary. (triggers: app/**/*.tsx, src/app/**/*.tsx, app/**/*.jsx, src/app/**/*.jsx, use client, Server Component, Client Component, hydration)
Best practices for managing state (Server URL vs Client Hooks). Use when managing URL state, client state, or global state in a Next.js application. (triggers: **/hooks/*.ts, **/store.ts, **/components/*.tsx, useState, useContext, zustand, redux)
Zero-runtime CSS strategies (Tailwind) and RSC compatibility. Use when implementing Tailwind CSS or zero-runtime styling compatible with React Server Components. (triggers: **/*.css, tailwind.config.ts, **/components/ui/*.tsx, tailwind, css modules, styled-components, clsx, cn)
Unit, Integration, and E2E testing standards for App Router. Use when writing unit, integration, or Playwright E2E tests for a Next.js App Router project. (triggers: **/*.test.{ts, tsx}, cypress/**, tests/**, vitest, playwright, msw, testing-library)
Ecosystem optimization, deployment, and developer flow. Use when configuring Next.js build optimization, deployment settings, or developer tooling. (triggers: next.config.js, package.json, Dockerfile, turbopack, output, standalone, lint, telemetry)
Next.js version migrations using official guides and codemods. Use when migrating a Next.js project to a new major version using codemods. (triggers: package.json, next upgrade, migration guide, codemod)
Universal standards for high-performance development. Use when optimizing, reducing latency, fixing memory leaks, profiling, or improving throughput.
PHP best practices, PSR standards, and code quality guidelines. Use when writing PHP following PSR standards, SOLID principles, or improving code quality. (triggers: **/*.php, psr-12, camelCase, PascalCase, dry, solid)
Claude Skills — questions
Answers built from the skills we actually parsed.