# VoltX.js
[](https://codecov.io/gh/stormlightlabs/volt)
[](https://jsr.io/@voltx/core)

> [!WARNING]
> VoltX.js is in active development.
>
> Breaking changes are expected until v1.0. Use in production at your own risk.
A lightweight reactive framework for declarative UIs. Build interactive applications using only HTML attributes powered by signals.
## Features
- Declarative, HTML-first reactivity via `data-volt-*` attributes
- Fine-grained signals and effects that update the DOM without a virtual DOM
- Zero runtime dependencies and a sub-15 KB gzipped core
- Built-in transport for SSE/WebSocket streams and JSON Patch updates
- Hydration-friendly rendering with SSR helpers
- Optional CSS design system and debug overlay for inspecting signal graphs
## Installation
### npm
```bash
npm install voltx.js
```
### JSR
```bash
npx jsr add @voltx/core
```
### Deno
```typescript
import { charge, signal } from "jsr:@voltx/core";
```
## Quick Start
```html
```
## Plugins
- `data-volt-persist` – automatically sync state across reloads and tabs
- `data-volt-url` – keep signals in sync with query params and hashes
- `data-volt-scroll` – manage scroll restoration and anchored navigation
- `data-volt-shift` – trigger reusable keyframe animations
- `data-volt-surge` – apply enter/leave transitions with view-transition support
Plugins are opt-in and can be combined declaratively or registered programmatically via `charge({ plugins: [...] })`.
## VoltX.css
VoltX ships with an optional classless CSS framework inspired by Pico CSS and Tufte CSS.
It provides beautiful, semantic styling without requiring any CSS classes.
Just write semantic HTML and it looks great. It's perfect for prototyping.
### Features
- **Typography**: Modular scale (1.25 ratio), harmonious spacing, and responsive sizing
- **Tufte-style sidenotes**: Margin notes using `` that float on desktop, inline on mobile
- **Components**: Styled dialogs, accordions (details/summary), and pure-CSS tooltips
- **Forms**: Consistent, accessible input styling with validation states
- **Tables**: Zebra striping and responsive behavior
- **Code blocks**: Syntax-appropriate styling for inline and block code
- **Dark mode**: Automatic theme switching based on system preferences
### Installation
Import the CSS in your application:
```typescript
import 'voltx.js/css';
```
Or include via CDN:
```html
```
### Usage
No classes needed. Just write semantic HTML:
```html
Beautiful Typography
This paragraph has proper spacing.
This sidenote appears in the margin on wide screens.
All elements are styled automatically.
Accordion Example
Content revealed when opened.
```
See the demo app's CSS section for comprehensive examples of all features.
## Documentation
Full documentation available at [https://stormlightlabs.github.io/volt/](https://stormlightlabs.github.io/volt/)
## Development
- `pnpm install` (at the repo root) to bootstrap the workspace
- `pnpm --filter lib dev` runs package scripts such as `build`, `test`, and `typecheck`
- `pnpm dev` spins up the playground in `lib/dev` for interactive testing
## License
MIT