Use Tandem Browser's local API on 127.0.0.1:8765 to inspect, browse, and interact with the user's shared browser safely. Prefer targeted tabs and sessions, use snapshot refs before raw DOM or JS, and stop on Tandem prompt-injection warnings or blocks.
Research how production Rails apps solve architectural problems using the Real World Rails repository. Use when the user wants to know how other apps handle something, find patterns, or compare approaches. Triggers on "rails patterns", "how do other apps", "real world rails", "research how apps do".
Use when making RPC calls, fetch requests, or any external I/O from handlers. Effect API with createEffect, S schema validation, context.effect(), preload optimization (handlers run twice), cache and rateLimit options.
Use when writing or editing event handlers. Handler registration, context API (entity CRUD, getWhere queries, chain, log), spread updates, indexer runtime API, and common pitfalls.
Use when defining or editing schema.graphql. Entity types, scalar types, enums, relationships, @derivedFrom, @index, @config directives, array rules, naming conventions, and schema-to-TypeScript type mapping.
Use when needing transaction-level data in handlers. Configure field_selection to include transaction fields on events, and access via event.transaction. No native transaction handler — access through event handlers.
Use when indexing all instances of a contract across all addresses (e.g., all ERC-20 transfers on a chain). Config setup (no address), wildcard handler option, and event.srcAddress.
Build a new read model following project conventions (event handlers, tests, migration, configuration)
Use when working on files in packages/plugins/, adding new plugins, refactoring plugin components/containers, writing storybooks for plugins, or wiring capabilities like react-surface or operation-resolver.
Implement proven backend architecture patterns including Clean Architecture, Hexagonal Architecture, and Domain-Driven Design. Use when architecting complex backend systems or refactoring existing applications for better maintainability.
NestJS best practices and architecture patterns for building production-ready applications. This skill should be used when writing, reviewing, or refactoring NestJS code to ensure proper patterns for modules, dependency injection, security, and performance.
Master REST and GraphQL API design principles to build intuitive, scalable, and maintainable APIs that delight developers. Use when designing new APIs, reviewing API specifications, or establishing API design standards.
Integrate Supabase Auth with Next.js App Router using middleware, callback handling, protected routes, and server/client client boundaries.
Use when doing ANY task involving Supabase. Triggers: Supabase products (Database, Auth, Edge Functions, Realtime, Storage, Vectors, Cron, Queues); client libraries and SSR integrations (supabase-js, @supabase/ssr) in Next.js, React, SvelteKit, Astro, Remix; auth issues (login, logout, sessions, JWT, cookies, getSession, getUser, getClaims, RLS); Supabase CLI or MCP server; schema changes, migrations, security audits, Postgres extensions (pg_graphql, pg_cron, pg_vector).
React composition patterns that scale. Use when refactoring components with boolean prop proliferation, building flexible component libraries, or designing reusable APIs. Triggers on tasks involving compound components, render props, context providers, or component architecture. Includes React 19 API changes.
React and Next.js performance optimization guidelines from Vercel Engineering. Use when writing, reviewing, or refactoring React components or Next.js App Router code for performance (waterfalls, bundle size, server/client performance, rerenders, rendering performance).
Complete guide for building accessible, high-UX forms in modern stacks (React/Next.js, Tailwind, Zod). Includes specific patterns for clickable areas, range sliders, output-inspired design, and WCAG compliance.
Build modern, composable, and accessible React UI components following the components.build specification. Use when creating, reviewing, or refactoring component libraries, design systems, or any reusable UI components. Triggers on tasks involving component APIs, composition patterns, accessibility, styling systems, or TypeScript props.
Use when creating HTML email templates with React components - welcome emails, password resets, notifications, order confirmations, newsletters, or transactional emails.
Best practices for Remotion - Video creation in React
Set up Tailwind v4 with shadcn/ui using @theme inline pattern and CSS variable architecture. Four-step pattern: CSS variables, Tailwind mapping, base styles, automatic dark mode. Prevents 8 documented errors. Use when initializing React projects with Tailwind v4, or fixing colors not working, tw-animate-css errors, @theme inline dark mode conflicts, @apply breaking, v3 migration issues.
Manage server state in React with TanStack Query v5. Covers useMutationState, simplified optimistic updates, throwOnError, network mode (offline/PWA), and infiniteQueryOptions. Use when setting up data fetching, fixing v4→v5 migration errors (object syntax, gcTime, isPending, keepPreviousData), or debugging SSR/hydration issues with streaming server components.
