Skill2.8k repo starsupdated 5d ago

generative-ui

The generative-ui skill provides design system guidelines and templates for creating interactive HTML and SVG widgets that render inline within claude.ai conversations using the show_widget tool. Use this skill when you need to build visual components like diagrams, flowcharts, charts, comparison grids, or interactive explainers, ensuring they follow Anthropic's flat design principles, proper structure ordering, typography standards, and seamless integration with the host interface.

View source Repository: finance-skills

Install in Claude Code

Copy

git clone --depth 1 https://github.com/himself65/finance-skills /tmp/generative-ui && cp -r /tmp/generative-ui/plugins/ui-tools/skills/generative-ui ~/.claude/skills/generative-ui

Then start a new Claude Code session; the skill loads automatically.

Definition

SKILL.md

# Generative UI Skill

This skill contains the complete design system for Claude's built-in `show_widget` tool — the generative UI feature that renders interactive HTML/SVG widgets inline in claude.ai conversations. The guidelines below are the actual Anthropic "Imagine — Visual Creation Suite" design rules, extracted so you can produce high-quality widgets directly without needing the `read_me` setup call.

**How it works**: On claude.ai, Claude has access to the `show_widget` tool which renders raw HTML/SVG fragments inline in the conversation. This skill provides the design system, templates, and patterns to use it well.

---

## Step 1: Pick the Right Visual Type

Route on the **verb**, not the noun. Same subject, different visual depending on what was asked:

| User says | Type | Format |
|---|---|---|
| "how does X work" | Illustrative diagram | SVG |
| "X architecture" | Structural diagram | SVG |
| "what are the steps" | Flowchart | SVG |
| "explain compound interest" | Interactive explainer | HTML |
| "compare these options" | Comparison grid | HTML |
| "show revenue chart" | Chart.js chart | HTML |
| "create a contact card" | Data record | HTML |
| "draw a sunset" | Art/illustration | SVG |

---

## Step 2: Build the Widget

### Structure (strict order)

```
<style>  →  HTML content  →  <script>
```

Output streams token-by-token. Styles must exist before the elements they target, and scripts must run after the DOM is ready.

### Philosophy

- **Seamless**: Users shouldn't notice where the host UI ends and your widget begins
- **Flat**: No gradients, mesh backgrounds, noise textures, or decorative effects. Clean flat surfaces
- **Compact**: Show the essential inline. Explain the rest in text
- **Text goes in your response, visuals go in the tool** — all explanatory text, descriptions, and summaries must be written as normal response text OUTSIDE the tool call. The tool output should contain ONLY the visual element

### Core Rules

- No `<!-- comments -->` or `/* comments */` (waste tokens, break streaming)
- No font-size below 11px
- No emoji — use CSS shapes or SVG paths
- No gradients, drop shadows, blur, glow, or neon effects
- No dark/colored backgrounds on outer containers (transparent only — host provides the bg)
- **Typography**: two weights only: 400 regular, 500 medium. Never use 600 or 700. Headings: h1=22px, h2=18px, h3=16px — all font-weight 500. Body text=16px, weight 400, line-height 1.7
- **Sentence case** always. Never Title Case, never ALL CAPS
- No mid-sentence bolding — entity names go in `code style` not **bold**
- No `<!DOCTYPE>`, `<html>`, `<head>`, or `<body>` — just content fragments
- No `position: fixed` — use normal-flow layouts
- No tabs, carousels, or `display: none` sections during streaming
- No nested scrolling — auto-fit height
- Corners: `border-radius: var(--border-radius-lg)` for cards, `var(--border-radius-md)` for elements
- No rounded corners on single-sided borders (border-left, border-top)
- **Round every displayed number** — use `Math.round()`, `.toFixed(n)`, or `Intl.NumberFormat`

### CDN Allowlist (CSP-enforced)

External resources may ONLY load from:
- `cdnjs.cloudflare.com`
- `cdn.jsdelivr.net`
- `unpkg.com`
- `esm.sh`

All other origins are blocked — the request silently fails.

### CSS Variables

**Backgrounds**: `--color-background-primary` (white), `-secondary` (surfaces), `-tertiary` (page bg), `-info`, `-danger`, `-success`, `-warning`
**Text**: `--color-text-primary` (black), `-secondary` (muted), `-tertiary` (hints), `-info`, `-danger`, `-success`, `-warning`
**Borders**: `--color-border-tertiary` (0.15α, default), `-secondary` (0.3α, hover), `-primary` (0.4α), semantic `-info/-danger/-success/-warning`
**Typography**: `--font-sans`, `--font-serif`, `--font-mono`
**Layout**: `--border-radius-md` (8px), `--border-radius-lg` (12px), `--border-radius-xl` (16px)

All auto-adapt to light/dark mode.

**Dark mode is mandatory** — every color must work in both modes:
- In HTML: always use CSS variables for text. Never hardcode colors like `color: #333`
- In SVG: use pre-built color classes (`c-blue`, `c-teal`, etc.) — they handle light/dark automatically
- Mental test: if the background were near-black, would every text element still be readable?

### `sendPrompt(text)`

A global function that sends a message to chat as if the user typed it. Use it when the user's next step benefits from Claude thinking. Handle filtering, sorting, toggling, and calculations in JS instead.

---

## Step 3: Render with `show_widget`

The `show_widget` tool is built into claude.ai — no activation needed. Pass your widget code directly:

```json
{
  "title": "snake_case_widget_name",
  "widget_code": "<style>...</style>\n<div>...</div>\n<script>...</script>"
}
```

| Parameter | Type | Required | Description |
|---|---|---|---|
| `title` | string | Yes | Snake_case identifier for the widget |
| `widget_code` | string | Yes | HTML or SVG code. For SVG: start with `<svg>`. For HTML: content fragment |

For SVG output: start `widget_code` with `<svg` — it will be auto-detected and wrapped appropriately.

---

## Step 4: Chart.js Template

For charts, use `onload` callback pattern to handle script load ordering:

```html
<div style="display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 12px;">
  <div style="background: var(--color-background-secondary); border-radius: var(--border-radius-md); padding: 1rem;">
    <div style="font-size: 13px; color: var(--color-text-secondary);">Label</div>
    <div style="font-size: 24px; font-weight: 500;" id="stat1">—</div>
  </div>
</div>

<div style="position: relative; width: 100%; height: 300px; margin-top: 1rem;">
  <canvas id="myChart"></canvas>
</div>

<div style="display: flex; align-items: center; gap: 12px; margin-top: 1rem;">
  <label style="font-size: 14px; color: var(--color-text-secondary);">Parameter</label>
  <input type="range" min="0" max="100" value="50" id="param" step="1"