Agents Inc.

test-custom-marketplace

agents-inc

Brief description of this skill

PostHog event tracking, user identification, group analytics for B2B, GDPR consent patterns. Use when implementing product analytics, tracking user behavior, setting up funnels, or configuring privacy-compliant tracking.

PostHog analytics and feature flags setup

Better Auth patterns, sessions, OAuth

GitHub Actions, pipelines, deployment

Drizzle ORM, queries, migrations

Prisma ORM, type-safe queries, migrations, relations

Resend + React Email templates

Resend email setup, domain verification

PostHog feature flags, rollouts, A/B testing. Use when implementing gradual rollouts, A/B tests, kill switches, remote configuration, beta features, or user targeting with PostHog.

Express.js routes, middleware, error handling, request/response patterns

Fastify routes, JSON Schema validation, plugin system, TypeScript type providers

Hono routes, OpenAPI, Zod validation

Pino logging, Sentry error tracking, Axiom - structured logging with correlation IDs, error boundaries, performance monitoring, alerting

Pino, Axiom, Sentry installation - one-time project setup for logging and error tracking with source maps upload

Query optimization, caching, indexing

Node.js CLI development with Commander.js, @clack/prompts, and picocolors. Command structure, interactive prompts, state machines, error handling, exit codes, configuration hierarchies.

Modern CLI development combining oclif's command framework with Ink's React-based terminal rendering

Environment configuration, Zod validation

Turborepo, workspaces, package architecture, @repo/* naming, exports, tree-shaking

ESLint 9 flat config, Prettier, TypeScript configuration, Vite, Husky + lint-staged, commitlint - build tooling for monorepos

Anti-over-engineering principles - surgical implementation, not architectural innovation. Use existing utilities, minimal changes, follow established conventions. No new abstractions.

Long-term context management protocol - maintain project continuity across sessions through systematic documentation. Progress tracking, decision logging, insight preservation.

Self-improvement protocol for agents modifying their own prompts/configurations. Evidence-based improvements, structured changes, proven patterns from research.

Investigation requirement - never speculate about code you haven't read. List files, read completely, base analysis on evidence. Prevents hallucination in coding agents.

Success criteria template - every task needs explicit, measurable criteria defining "done". Specific, measurable, achievable, verifiable requirements with verification checklist.

Write verification protocol - never report success without verifying work was actually saved. Re-read files after edits, verify changes exist, only report success after verification passes.

Investigation flow (Glob -> Grep -> Read), evidence-based research with file:line references, structured output format for AI consumption. Use for pattern discovery, implementation research, and codebase investigation.

CLI code review patterns. Use when reviewing CLI applications built with Commander.js, @clack/prompts, picocolors. Covers exit codes, signal handling, error messages, user experience, testing adequacy.

Code review patterns, feedback principles. Use when reviewing PRs, implementations, or making approval/rejection decisions. Covers self-correction, progress tracking, feedback principles, severity levels.

Expo managed workflow

React Native mobile development patterns - New Architecture (Fabric, TurboModules, JSI), component architecture, React Navigation 7+, styling with StyleSheet/NativeWind, FlashList v2 optimization, gestures with Reanimated 4, platform-specific code, Expo SDK 52-54, React 19 features

Authentication, authorization, secrets management, XSS prevention, CSRF protection, Dependabot configuration, vulnerability scanning, DOMPurify sanitization, CSP headers, CODEOWNERS, HttpOnly cookies

WCAG, ARIA, keyboard navigation

CSS Animation patterns - transitions, keyframes, scroll-driven animations, View Transitions API, GPU-accelerated properties, accessibility with prefers-reduced-motion

Motion (formerly Framer Motion) animation patterns - motion components, variants, gestures, layout animations, scroll-linked animations, accessibility

View Transitions API patterns - same-document transitions, cross-document MPA transitions, shared element animations, pseudo-element styling, accessibility

Apollo Client GraphQL patterns - useQuery, useMutation, cache management, optimistic updates, subscriptions

URQL GraphQL client patterns - useQuery, useMutation, exchange architecture, caching strategies, subscriptions

SWR data fetching patterns - useSWR, useSWRMutation, caching, revalidation, infinite scroll

tRPC type-safe API patterns, procedures, React Query integration

Error boundary patterns, fallback UI, reset/retry functionality, react-error-boundary library

TypeScript Result/Either types for type-safe error handling, railway-oriented programming patterns, error as values

File upload patterns - drag-drop dropzones, chunked/resumable uploads, S3 presigned URLs, file validation (MIME type, magic bytes), progress tracking, image preview, accessibility (ARIA)

Client-side image handling - preview generation, Canvas API resizing, compression, EXIF orientation, format conversion, memory management with object URL cleanup

React Hook Form patterns - useForm, Controller, useFieldArray, validation resolver, performance optimization

VeeValidate v4 patterns - useForm, useField, defineField, useFieldArray, schema validation with Composition API

Zod schema validation patterns for TypeScript - schema definitions, type inference, refinements, transforms, discriminated unions

Angular 17-19 standalone components, signals, control flow, dependency injection patterns

Next.js 15 App Router patterns - file-based routing, Server/Client Components, streaming, Suspense, metadata API, parallel routes, Turbopack, async params

Server Actions patterns for mutations, revalidation, and form handling in Next.js App Router

Nuxt 3 patterns - file-based routing, data fetching (useFetch/useAsyncData), useState, server routes, middleware, auto-imports, layouts, SEO

Component architecture, hooks, patterns

File-based routing, loaders, actions, defer streaming, useFetcher, error boundaries, progressive enhancement

SolidJS fine-grained reactivity patterns - signals, effects, memos, stores, createResource, control flow components, Suspense, SolidStart

Vue 3 Composition API patterns, reactivity primitives, composables, lifecycle hooks

Type-safe i18n for Next.js App Router

ICU message format internationalization

Type-safe i18n for Vue 3 Composition API

MSW handlers, browser/server workers, test data. Use when setting up API mocking for development or testing, creating mock handlers with variants, or sharing mocks between browser and Node environments.

Bundle optimization, render performance

Local-first architecture with sync queues

Service Worker lifecycle, caching strategies, offline patterns, update handling, precaching, runtime caching

Socket.IO v4.x client patterns, connection lifecycle, reconnection, authentication, rooms, namespaces, acknowledgments, binary data, TypeScript integration

Server-Sent Events for unidirectional server-to-client streaming, EventSource API, fetch streaming, reconnection patterns, message parsing

Native WebSocket API patterns, connection lifecycle, reconnection strategies, heartbeat, message typing, binary data, custom hooks

REST APIs, React Query, data fetching

Atomic state management with auto-dependency tracking

MobX observable state management patterns with mobx-react-lite. Use when implementing reactive client state with observables, computed values, actions, and the observer HOC.

NgRx SignalStore patterns for Angular state management. Use when managing client state with Angular Signals, composing store features, handling entities, or integrating RxJS effects.

Pinia stores, Vue 3 state patterns. Use when managing client state in Vue applications, choosing between Options/Setup stores, composing stores, or implementing persistence.

Redux Toolkit patterns for complex client state. Use when managing enterprise-scale state, needing DevTools, entity normalization, or RTK Query for data fetching.

Zustand stores, client state patterns. Use when deciding between Zustand vs useState, managing global state, avoiding Context misuse, or handling form state.

Class Variance Authority - type-safe component variant styling with cva(), compound variants, and VariantProps

SCSS Modules, cva, design tokens

Tailwind CSS v4 - utility-first CSS framework with CSS-first configuration

Cypress E2E testing patterns - test structure, data-cy selectors, cy.intercept() mocking, custom commands, fixtures, component testing, accessibility testing with cypress-axe, and CI/CD integration

Playwright E2E testing patterns - test structure, Page Object Model, locator strategies, assertions, network mocking, visual regression, parallel execution, fixtures, and configuration

React Testing Library patterns - query hierarchy, userEvent, async utilities, renderHook, custom render with providers, accessibility-first testing

Playwright E2E, Vitest, React Testing Library - E2E for user flows, unit tests for pure functions only, network-level API mocking - inverted testing pyramid prioritizing E2E tests

Vue Test Utils patterns - mount, shallowMount, wrapper API, trigger, setValue, flushPromises, testing composables, Pinia store mocking

Storybook 8 patterns - CSF 3.0, args, controls, autodocs, play functions, interaction testing, visual testing, addons configuration

Unstyled accessible UI primitives

shadcn/ui component library patterns, CLI usage, theming, customization

TanStack Table v8 patterns - useReactTable, column definitions, sorting, filtering, pagination, row selection, virtual scrolling, server-side data

date-fns patterns for TypeScript - formatting, parsing, manipulation, comparison, timezone handling, and internationalization

Modern native JavaScript (ES2022-ES2025) utility patterns - array methods, object manipulation, set operations, deep cloning, and function utilities that replace lodash