sanity

Add and review Sanity config properties that are reduced across root config and plugins. Use when adding beta flags, feature config, workspace/source options, default plugin gates, or resolved Source fields in packages/sanity/src/core/config.

Create and wire Sanity core plugins using the monorepo's default plugin conventions. Use when adding, modifying, or reviewing plugins under packages/sanity/src/core, especially plugins added through resolveDefaultPlugins or studio.components middleware.

Explain and create Sanity Studio plugins using the public plugin and tool APIs. Use when creating user-facing plugins, adding tools through plugins, or when an agent needs to understand what a Sanity plugin can configure before applying monorepo-specific default plugin wiring.

Simplifies code for clarity. Use when refactoring code for clarity without changing behavior. Use when code works but is harder to read, maintain, or extend than it should be. Use when reviewing code that has accumulated unnecessary complexity.

Optimizes application performance. Use when performance requirements exist, when you suspect performance regressions, or when Core Web Vitals or load times need improvement. Use when profiling reveals bottlenecks that need fixing.

How to write idiomatic, efficient RxJS code. Use this skill whenever the user is writing, refactoring, reviewing, or debugging code that uses RxJS — including any file that imports from 'rxjs' or 'rxjs/operators'. Trigger on mentions of observables, subscriptions, RxJS operators, or reactive streams. Even if the user doesn't say "RxJS" explicitly, activate when you see patterns like `.pipe()`, `.subscribe()`, `Observable`, `Subject`, `BehaviorSubject`, `switchMap`, `mergeMap`, or similar.

Write PR descriptions and release notes for the Sanity monorepo. Follows the repo's PR template with Description, What to review, Testing, and Notes for release sections. Auto-triggers when creating PRs via `gh pr create`. Use when creating pull requests, writing PR descriptions, drafting release notes, or when user mentions PR, pull request, or release notes.

Use when writing Playwright tests, fixing flaky tests, debugging failures, implementing Page Object Model, configuring CI/CD, optimizing performance, mocking APIs, handling authentication or OAuth, testing accessibility (axe-core), file uploads/downloads, date/time mocking, WebSockets, geolocation, permissions, multi-tab/popup flows, mobile/responsive layouts, touch gestures, GraphQL, error handling, offline mode, multi-user collaboration, third-party services (payments, email verification), console error monitoring, global setup/teardown, test annotations (skip, fixme, slow), test tags (@smoke, @fast, @critical, filtering with --grep), project dependencies, security testing (XSS, CSRF, auth), performance budgets (Web Vitals, Lighthouse), iframes, component testing, canvas/WebGL, service workers/PWA, test coverage, i18n/localization, Electron apps, or browser extension testing. Covers E2E, component, API, visual, accessibility, security, Electron, and extension testing.

Automates browser interactions for web testing, form filling, screenshots, and data extraction. Use when the user needs to navigate websites, interact with web pages, fill forms, take screenshots, test web applications, or extract information from web pages.

Test-driven development with red-green-refactor loop. Use when user wants to build features or fix bugs using TDD, mentions "red-green-refactor", wants integration tests, or asks for test-first development.

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.