Checkbox — logic2b/ui

Accept terms and conditions

import { Checkbox } from "@/components/ui/checkbox"
import { Label } from "@/components/ui/label"

export default function CheckboxDemo() {
  return (
    <div className="flex items-center gap-3">
      <Checkbox id="checkbox-terms" />
      <Label htmlFor="checkbox-terms">Accept terms and conditions</Label>
    </div>
  )
}

Installation

npx logic2b@latest add checkbox

Working with an AI assistant? Copy this prompt into Claude Code, Cursor or Copilot — it carries the install steps, a no-CLI fallback and a verification checklist.

Add the "checkbox" item from the logic2b ui registry (https://ui.logic2b.com) to this project. Follow every step and verify at the end.

## Steps

1. If the project has no `components.json` yet, set up logic2b ui first:

   ```bash
   npx logic2b@latest init
   ```

2. Install the item (the CLI resolves registry dependencies automatically):

   ```bash
   npx logic2b@latest add checkbox
   ```

3. Install any npm dependencies the command prints.

## If the CLI is not available

Do it manually from the registry payload:

1. Fetch https://ui.logic2b.com/r/checkbox.json.
2. Write every entry in `files[]` to its mapped project path (see below).
3. Repeat (recursively) for each name in `registryDependencies`.
4. Install every package listed in `dependencies` across those payloads.

## Registry reference

- Index of every item: https://ui.logic2b.com/r/index.json
- Item payload (full source): https://ui.logic2b.com/r/<name>.json
- Usage examples per item: https://ui.logic2b.com/r/demos/index.json → https://ui.logic2b.com/r/demos/<demo>.json
- Docs index for agents: https://ui.logic2b.com/llms.txt (full docs: https://ui.logic2b.com/llms-full.txt)
- Every docs page is Markdown when you append `.md` to its URL.

Registry file paths map to project paths like this:
- `ui/*` → `@/components/ui/*`
- `blocks/<name>/*` → `@/components/*`
- `charts/*` → `@/components/charts/*`
- `hooks/*` → `@/hooks/*`
- `lib/utils.ts` → `@/lib/utils.ts`
- `theme.css` → next to the project's Tailwind entry stylesheet

## Conventions (do not break these)

- Tailwind CSS v4 (CSS-first config; no tailwind.config.js needed) and React 19.
- All colors go through semantic tokens (`bg-primary`, `text-muted-foreground`,
  `border-border`, …). Never hardcode hex/oklch values in components.
- Dark mode is class-based: toggle `.dark` on `<html>`.
- Icons come from lucide-react.

## Verify before finishing

1. The dev server starts and the app renders without console errors.
2. TypeScript compiles (`tsc --noEmit` or the framework's check).
3. Components use the theme: a `<Button>` shows the primary token color,
   and toggling `.dark` on `<html>` switches the palette.

Install the dependencies:

npm install radix-ui lucide-react

Copy into ui/checkbox.tsx:

"use client"

import * as React from "react"
import { Checkbox as CheckboxPrimitive } from "radix-ui"
import { CheckIcon } from "lucide-react"

import { cn } from "@/lib/utils"

function Checkbox({
  className,
  ...props
}: React.ComponentProps<typeof CheckboxPrimitive.Root>) {
  return (
    <CheckboxPrimitive.Root
      data-slot="checkbox"
      className={cn(
        "peer border-input dark:bg-input/30 data-[state=checked]:bg-primary data-[state=checked]:text-primary-foreground dark:data-[state=checked]:bg-primary data-[state=checked]:border-primary focus-visible:border-ring focus-visible:ring-ring/50 aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive size-4 shrink-0 rounded-[4px] border shadow-xs transition-shadow outline-none focus-visible:ring-[3px] disabled:cursor-not-allowed disabled:opacity-50",
        className
      )}
      {...props}
    >
      <CheckboxPrimitive.Indicator
        data-slot="checkbox-indicator"
        className="flex items-center justify-center text-current transition-none"
      >
        <CheckIcon className="size-3.5" />
      </CheckboxPrimitive.Indicator>
    </CheckboxPrimitive.Root>
  )
}

export { Checkbox }

Usage

import { Checkbox } from "@/components/ui/checkbox"

<Checkbox id="terms" />

API

Prop	Type	Default
`checked` / `defaultChecked`	`boolean \| "indeterminate"` — controlled/uncontrolled state	—
`onCheckedChange`	`(checked: boolean \| "indeterminate") => void`	—
`disabled`	`boolean`	`false`
`required`	`boolean`	`false`
`name` / `value`	`string` — form field name and submitted value	—

Examples

With text

Pair the checkbox with a Label and helper description.

Enable notifications

You can turn these off at any time in settings.

import { Checkbox } from "@/components/ui/checkbox"
import { Label } from "@/components/ui/label"

export default function CheckboxWithTextDemo() {
  return (
    <div className="flex items-start gap-3">
      <Checkbox id="checkbox-notifications" defaultChecked />
      <div className="grid gap-1.5">
        <Label htmlFor="checkbox-notifications">Enable notifications</Label>
        <p className="text-muted-foreground text-sm">
          You can turn these off at any time in settings.
        </p>
      </div>
    </div>
  )
}

Disabled

Accept terms (unavailable)

import { Checkbox } from "@/components/ui/checkbox"
import { Label } from "@/components/ui/label"

export default function CheckboxDisabledDemo() {
  return (
    <div className="flex items-center gap-3">
      <Checkbox id="checkbox-disabled" disabled />
      <Label htmlFor="checkbox-disabled">Accept terms (unavailable)</Label>
    </div>
  )
}

Accessibility

Renders a native-equivalent control with role="checkbox" and reflects state via aria-checked (including the mixed/indeterminate state).
Space toggles the focused checkbox; it is reachable and focusable with Tab.
Associate a Label via htmlFor matching the checkbox id so clicking the text toggles it.