frontend

Home Assistant frontend component patterns. Use when implementing or reviewing dialogs, ha-form, ha-alert, keyboard shortcuts, tooltips, panels, Lovelace cards, or ha-button usage.

Home Assistant frontend Lit context and hass migration guidance. Use when adding or changing component state access, replacing hass reads, consuming entity or registry contexts, or reviewing rerender behavior.

Home Assistant standalone demo structure, configurations, URL navigation, mocked APIs, shared demo stubs used by gallery, and verification. Use when changing files under demo/, changing gallery consumers of demo/src/stubs/, or running and validating the demo.

Home Assistant frontend event patterns. Use when typing event handlers, using HASSDomEvent types, dispatching with fireEvent, or declaring HASSDomEvents and event maps.

Home Assistant frontend gallery structure, pages, demos, content, and verification. Use when changing files under gallery/, including gallery markdown, TypeScript demos, sidebar entries, mock data, page generation, or gallery builds.

Home Assistant frontend Lit conventions. Use when working with reactive properties, internal state, DOM queries, lifecycle methods, or render-derived state.

Home Assistant frontend PR and review guidance. Use when reviewing frontend changes, preparing a PR, checking recurring review issues, or applying the PR template.

Home Assistant frontend styling, theming, spacing, responsive layout, RTL, and View Transitions guidance. Use when editing CSS, layout, motion, or visual component structure.

Home Assistant frontend testing and validation workflow. Use when adding or updating tests, running lint, TypeScript checks, Vitest, Playwright e2e suites, dev servers, or chart-data benchmarks.

Home Assistant frontend TypeScript conventions. Use when defining or reviewing backend data contracts, optional schemas, shared types, assertions, or Lit lifecycle types.

Home Assistant frontend copy, localization, terminology, and user-facing text guidance. Use when adding or reviewing labels, buttons, dialogs, errors, translations, or UI strings.