Use when working with Effect-TS v4 (effect@4.0.0-beta.x) - a functional programming library for TypeScript. Covers Effect, Option, Result (renamed from Either), Context, Layer, Stream, Schedule, Schema, and ecosystem packages. Triggers on: effect v4, effect-smol, effect/unstable/* imports, Context.Service (replaces v3 Context.Tag/GenericTag/Effect.Tag), httpapi-seams, integration seam, tracer bullet, HttpApiMiddleware, effect-native architecture / app structure, three-slot DI, Environment Context.Reference, AppConfig, catchDbErrors, RequestContext seam, Layer.buildWithMemoMap, @effect/vitest v4, Result (instead of Either), Effect.catch (instead of catchAll), Effect.forkChild (instead of fork), Effect.tx / Effect.txRetry (replace v3 STM.commit/retry), Tx* primitives (TxRef/TxHashMap/TxQueue replace v3 TRef/TMap/TQueue), drizzle-orm/effect-postgres / PgDrizzle.make / EffectPgDatabase / defineRelations (Drizzle 1.0 + Effect integration), @effect/sql-pg. Do NOT use for effect 3.x / @effect/platform as a separate
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 improvements.
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.
Guide the operator through safe incident triage on explicit node scope before taking action.
Use Scout plugin actions and logs deliberately instead of treating every problem like a raw shell task.