# Signature Pad (Notchset): prompt.md (v1.0.0)

- id: `signature-pad` · version 1.0.0 · component · pro (Pro)
- category: Inputs
- build: Base UI (one set of files; its dependencies follow the build)
- install (this build): `npx shadcn@latest add @beautiful-ui-pro/signature-pad`
- npm dependencies: none
- registry dependencies: utils, @beautiful-ui/segmented-control, https://beautiful-ui.dev/r/notchset-foundation.json
- docs: https://beautiful-ui.dev/components/signature-pad
- The install command carries everything this item needs (files, CSS, tokens, npm and registry dependencies). Prefer it to copying source by hand.

A signature pad with pressure-like ink from pen speed, a ruled baseline, undo, replay at real timing with a ring on the pen tip, PNG and SVG export, and a stamp that pops in once signed.

## Build it
- Stack: React 19 (`ref` is a plain prop), TypeScript, Tailwind CSS v4 utilities, a shadcn-initialised project with the `@/*` alias.
- Packages: none beyond React.
- Files: `components/ui/notchset/signature-pad.tsx`; shared code: `lib/beautiful-ui/notchset/calendar.tsx`, `lib/beautiful-ui/notchset/instrument.tsx`, `lib/beautiful-ui/notchset/root.ts`.
- Registry dependencies, installed with it automatically: shadcn `utils` (cn), `segmented-control`, `notchset-foundation`.
- Builds: one set of files for both, but its dependencies come in Base UI and Radix builds. Install the one that matches the project (see Install): a free item's bare URL installs the Base UI build of it and its dependencies.
- Exports to keep: `SignaturePad`, and every exported type.
- CSS: the install adds the notchset foundation (tokens, keyframes, motion levels) to your global stylesheet once. Nothing to import by hand.
- Re-running `add` (or `--overwrite`) re-applies those rules: put overrides in your own CSS, never in the installed rules.
- Tokens: retheme with the `--notchset-*` custom properties (`--notchset-check`, `--notchset-control-edge`, `--notchset-draw-from`, `--notchset-ease-bloom`, `--notchset-ease-travel`, `--notchset-fade`, `--notchset-focus-color`, `--notchset-focus-inset`, `--notchset-life-from`, `--notchset-life-ms`, `--notchset-node-blink`, `--notchset-node-bloom`, `--notchset-node-delay`, `--notchset-plate-color`, `--notchset-rise-from`, `--notchset-rule`, `--notchset-scroll`, `--notchset-signal`, `--notchset-sweep-to`). Never add Tailwind colour classes inside the component.

```tsx
import { SignaturePad, type SignatureResult } from "@/components/ui/notchset/signature-pad";
```

## Parts

| Part | data-slot | What it is for |
|---|---|---|
| `SignaturePad` | `signature-pad` | The pad, controls and sign button. |

Style a part with `[data-slot="<slot>"]` selectors or its `className`; keep the attributes when editing.

## Sound
- Keep every `data-slot` and `data-sound` attribute: the sound layer reads them.
- Installing this item adds no audio. Nothing plays until the app mounts `SoundProvider` once (install: `npx shadcn@latest add https://beautiful-ui.dev/r/notchset-sound.json`, import from `@/components/ui/notchset/sound-provider`); `useSound()` gives `muted` and `setMuted` for a mute control. Without a provider the audio engine never loads.

## Match the original
- Read `components/ui/notchset/signature-pad.tsx` as the reference implementation before changing or recreating anything, and match it: sizes, colours per theme, motion timings, copy and behaviour.
- If you deviate (a prop you can't honour, a style you changed, a dependency you swapped), say so in your reply, part by part.
- Keep the accessibility contract, the keyboard map and the motion levels listed below.

## Use it when
- signature pad, e-signature, sign document, approval signature, canvas drawing, Notchset
- Approving a document where a drawn signature is expected

### Not when
- As the only way to sign: offer a typed name too, for keyboard and screen-reader users

## Mistakes
- Hash on the server: the stamp shows what onSign returns

## Usage

```tsx
"use client";

import { SignaturePad, type SignatureResult } from "@/components/ui/notchset/signature-pad";

/** Your server stores the signature and returns a stamp and hash to show under it. */
async function signOnServer(result: SignatureResult) {
  const res = await fetch("/api/sign", { method: "POST", headers: { "content-type": "application/json" }, body: JSON.stringify({ svg: result.svg }) });
  if (!res.ok) throw new Error(`Signing failed (${res.status})`);
  return (await res.json()) as { stamp: string; hash: string };
}

export function SignOff() {
  return <SignaturePad signer={{ name: "Maya Kerr", title: "ML Lead" }} date="OCT 02 2026" onSign={signOnServer} />;
}
```

## Props

| Prop | Type | Default | What it does |
|---|---|---|---|
| `signer` | `{ name, title? }` |  | Printed under the line. |
| `date` | `string` |  | Printed at the line's end. |
| `onSign` | `(result) => Promise<{ stamp, hash }>` |  | Gets PNG, SVG and the strokes; returns the stamp's lines. |
| `weights / weightLabels` | `number[] / string[]` |  | Pen widths (default 1.3, 2.1, 3.1). |
| `fileName` | `string` |  | For PNG and SVG downloads. |

Full docs: https://beautiful-ui.dev/components/signature-pad

## Customising
- Colours: the component reads your shadcn tokens (`--background`, `--foreground`, `--border` …), refined by the `--notchset-*` tokens. The signal colour is `--notchset-signal` (it falls back to `--destructive`). Set tokens on `:root`, or on any container to retheme one area.
- Dark mode follows the `.dark` class on an ancestor (the shadcn and next-themes convention).
- Update later by re-running the install with `--overwrite` (review the diff if you edited it). Changelog: https://beautiful-ui.dev/r/changelog.json

## Keyboard

| Keys | Action |
|---|---|
| Tab | Weight, undo, replay, clear, export and sign |

## Performance

- New segments draw as they arrive; full redraws only on undo, resize or theme change.

## Responsive

- The canvas tracks its size (ResizeObserver) at device pixel ratio.

## Motion inventory

| Interaction | What moves |
|---|---|
| Ink | Width follows speed (faster is thinner), smoothed 60/40 |
| Replay | Real timing at 1.6×, 140ms between strokes, a 5px ring on the tip |
| Sign | A stamp pops in from 118%, tilted 2° (420ms) |

## Accessibility contract (preserve when editing)
- The canvas is an image with a label; every control is a labelled button
- Provide a typed-signature fallback alongside it

## Install

```bash
npx shadcn@latest add @beautiful-ui-pro/signature-pad
```

Pro item: needs the `@beautiful-ui-pro` registry in `components.json` and `BEAUTIFUL_UI_TOKEN` in `.env.local` (https://beautiful-ui.dev/account). Setup: https://beautiful-ui.dev/docs/pro. Your components.json `style` picks the build: radix-*, new-york and default get Radix, base-* gets Base UI.

## Credits
- Built on shadcn/ui (https://ui.shadcn.com)

The notchset foundation (the tokens listed above, keyframes and motion levels) installs once with the first component; its CSS is public at https://beautiful-ui.dev/r/notchset-foundation.json.