react

Use when: extracting, reusing, or naming hooks, state management, or other component-agnostic behavior in Primer React, or when a component's behavior hook wraps a native element with built-in behavior such as `<dialog>`. Covers the compound behavior-hook pattern (prop-getters), the controlled component contract for wrapping native elements, the difference between a component's own hook and a generic reusable utility, naming conventions, and where utilities live in the package.

Use when: building, modifying, or wrapping compound components that use child-component "slots" in Primer React. Covers when to add a `__SLOT__` marker, the `useSlots` hook, the `isSlot` helper, the `asSlot` wrapper helper, naming conventions for slot symbols, and common pitfalls.

Use when: starting, checking, or using the Storybook dev server; looking up Primer React component stories, props, or documentation; previewing component variants; writing or verifying Storybook stories; using the primer-storybook MCP to explore components. Covers starting Storybook, checking if it is running, and using MCP tools (list-all-documentation, get-documentation, get-storybook-story-instructions, preview-stories) to look up components.

Use when: authoring, modifying, or reviewing Primer React components, hooks, utilities, or component APIs.

Turborepo monorepo build system guidance. Triggers on: turbo.json, task pipelines, dependsOn, caching, remote cache, the "turbo" CLI, --filter, --affected, CI optimization, environment variables, internal packages, monorepo structure/best practices, and boundaries. Use when user: configures tasks/workflows/pipelines, creates packages, sets up monorepo, shares code between apps, runs changed/affected packages, debugs cache, or has apps/packages directories.