• GitHub (this package): https://github.com/Nucleify/nucleify-ui
• GitHub (framework using this package): https://github.com/Nucleify/Nucleify

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Lit 3 web component library. Import only the components you use — your bundler will include just those modules.

Install

npm install nucleify-ui

Peer dependencies (install in your app if not already present):

npm install lit iconify-icon
# optional, only for nui-chart:
npm install chart.js

Use components

Register components with side-effect imports:

import 'nucleify-ui/components/nui-button';
import 'nucleify-ui/components/nui-dialog';

Apply theme tokens on document.body:

import { applyTheme } from 'nucleify-ui/theme';

applyTheme('nuxt', 'dark');

Load global styles in your app entry:

import 'nucleify-ui/styles/global.css';
import 'nucleify-ui/styles/variables.css';

Then use tags in HTML or JSX:

<nui-button label="Save" severity="primary"></nui-button>

Tree-shaking

Each component is a separate export. Import only what you need:

import 'nucleify-ui/components/nui-button';
import 'nucleify-ui/components/nui-dialog';

With Vite or esbuild, unused components stay out of the client bundle. lit, iconify-icon, and (optionally) chart.js should be installed once in your app — they are peer dependencies.

Example Vite entry:

import 'nucleify-ui/styles/variables.css';
import 'nucleify-ui/styles/global.css';
import { applyTheme } from 'nucleify-ui/theme';
import 'nucleify-ui/components/nui-button';

applyTheme('nuxt', 'dark');

TypeScript

The library ships full .d.ts declarations for every component: props, HTMLElementTagNameMap, typed custom events, and slot JSDoc.

Component props

Register the component, then use typed DOM references:

import 'nucleify-ui/components/nui-button';
import 'nucleify-ui/components/nui-dialog';

const button = document.querySelector('nui-button')!;
button.label = 'Save';
button.severity = 'danger';

const dialog = document.querySelector('nui-dialog')!;
dialog.visible = true;
dialog.position = 'center';

Import helper types from the component types subpath:

import type { ButtonProps } from 'nucleify-ui/components/nui-button/types';
import type { DialogProps, DialogPosition } from 'nucleify-ui/components/nui-dialog/types';

Custom events

Components that emit custom events expose a typed *EventMap and typed addEventListener / removeEventListener:

import 'nucleify-ui/components/nui-dialog';

import type { NuiDialogEventMap } from 'nucleify-ui/components/nui-dialog/types';

const dialog = document.querySelector('nui-dialog')!;

dialog.addEventListener('change', (event) => {
  event.detail.visible;
  event.detail.originalEvent;
});

dialog.addEventListener('show', () => {
  // ...
});

// Event map type for handlers or wrappers
type DialogChange = NuiDialogEventMap['change'];

Shared event detail helpers live in nucleify-ui/types/component-events:

import type {
  ValueEventDetail,
  ValueChangeEventDetail,
  OriginalEventDetail,
} from 'nucleify-ui/types/component-events';

Shared types

import type { NuiType } from 'nucleify-ui/types/nui-type';
import { applyTheme, type Palette, type ThemeMode } from 'nucleify-ui/theme';
import {
  nucleifyStyles,
  type NuiComponentTag,
  type NuiStylesMap,
} from 'nucleify-ui/config';

Override component CSS

Pass a map of component tags to CSS file paths. Call before importing components.

Option A — one call in main.ts (paths relative to your entry file):

import { nucleifyStyles } from 'nucleify-ui/config';

nucleifyStyles(
  {
    'nui-button': './styles/nui-button.css',
    'nui-card': './styles/nui-card.css',
  },
  import.meta.url,
);

import 'nucleify-ui/components/nui-button';

Option B — config file with only the map (recommended):

// nucleify-ui.config.ts
import { createNucleifyStyles } from 'nucleify-ui/config';

const nucleifyStyles = createNucleifyStyles(import.meta.url);

nucleifyStyles({
  'nui-button': './styles/nui-button.css',
  'nui-card': './styles/nui-card.css',
});

// main.ts
import './nucleify-ui.config.js';
import 'nucleify-ui/components/nui-button';

Option C — CSS in public/ (no import.meta.url):

nucleifyStyles({
  'nui-button': '/styles/nui-button.css',
});

Copy defaults from node_modules/nucleify-ui/dist/components/nui-button/styles.css as a starting point.

Use unstyled on a component instance to disable styles for that element only.

Playground

After installing in a project, add to your package.json:

{
  "scripts": {
    "playground": "nucleify-ui-playground"
  }
}

Run:

npm run playground

This starts the interactive component playground from the installed package (port 8000 by default).

Local development (this repo)

npm install
npm run start     # or npm run playground
npm run build
npm run check
npm run test      # includes component type audit
npm run types:audit

Package exports

| Import | Description | |--------|-------------| | nucleify-ui | Theme helpers, config API, shared types | | nucleify-ui/config | nucleifyStyles() — CSS overrides | | nucleify-ui/theme | applyTheme() | | nucleify-ui/types/component-events | Shared custom event detail types | | nucleify-ui/types/nui-type | NuiType, nuiTypeProperty | | nucleify-ui/styles/* | CSS token files | | nucleify-ui/components/nui-* | Individual web components | | nucleify-ui/components/nui-*/types | Component props, unions, *EventMap |