penpot-uiux-design

What this skill does

# Penpot UI/UX Design Guide

Create professional, user-centered designs in Penpot using the `penpot/penpot-mcp` MCP server and proven UI/UX principles.

## Available MCP Tools

| Tool | Purpose |
| ---- | ------- |
| `mcp__penpot__execute_code` | Run JavaScript in Penpot plugin context to create/modify designs |
| `mcp__penpot__export_shape` | Export shapes as PNG/SVG for visual inspection |
| `mcp__penpot__import_image` | Import images (icons, photos, logos) into designs |
| `mcp__penpot__penpot_api_info` | Retrieve Penpot API documentation |

## MCP Server Setup

The Penpot MCP tools require the `penpot/penpot-mcp` server running locally. For detailed installation and troubleshooting, see [setup-troubleshooting.md](references/setup-troubleshooting.md).

### Before Setup: Check If Already Running

**Always check if the MCP server is already available before attempting setup:**

1. **Try calling a tool first**: Attempt `mcp__penpot__penpot_api_info` - if it succeeds, the server is running and connected. No setup needed.

2. **If the tool fails**, ask the user:
   > "The Penpot MCP server doesn't appear to be connected. Is the server already installed and running? If so, I can help troubleshoot. If not, I can guide you through the setup."

3. **Only proceed with setup instructions if the user confirms the server is not installed.**

### Quick Start (Only If Not Installed)

```bash
# Clone and install
git clone https://github.com/penpot/penpot-mcp.git
cd penpot-mcp
npm install

# Build and start servers
npm run bootstrap
```

Then in Penpot:
1. Open a design file
2. Go to **Plugins** → **Load plugin from URL**
3. Enter: `http://localhost:4400/manifest.json`
4. Click **"Connect to MCP server"** in the plugin UI

### VS Code Configuration

Add to `settings.json`:
```json
{
  "mcp": {
    "servers": {
      "penpot": {
        "url": "http://localhost:4401/sse"
      }
    }
  }
}
```

### Troubleshooting (If Server Is Installed But Not Working)

| Issue | Solution |
| ----- | -------- |
| Plugin won't connect | Check servers are running (`npm run start:all` in penpot-mcp dir) |
| Browser blocks localhost | Allow local network access prompt, or disable Brave Shield, or try Firefox |
| Tools not appearing in client | Restart VS Code/Claude completely after config changes |
| Tool execution fails/times out | Ensure Penpot plugin UI is open and shows "Connected" |
| "WebSocket connection failed" | Check firewall allows ports 4400, 4401, 4402 |

## Quick Reference

| Task | Reference File |
| ---- | -------------- |
| MCP server installation & troubleshooting | [setup-troubleshooting.md](references/setup-troubleshooting.md) |
| Component specs (buttons, forms, nav) | [component-patterns.md](references/component-patterns.md) |
| Accessibility (contrast, touch targets) | [accessibility.md](references/accessibility.md) |
| Screen sizes & platform specs | [platform-guidelines.md](references/platform-guidelines.md) |

## Core Design Principles

### The Golden Rules

1. **Clarity over cleverness**: Every element must have a purpose
2. **Consistency builds trust**: Reuse patterns, colors, and components
3. **User goals first**: Design for tasks, not features
4. **Accessibility is not optional**: Design for everyone
5. **Test with real users**: Validate assumptions early

### Visual Hierarchy (Priority Order)

1. **Size**: Larger = more important
2. **Color/Contrast**: High contrast draws attention
3. **Position**: Top-left (LTR) gets seen first
4. **Whitespace**: Isolation emphasizes importance
5. **Typography weight**: Bold stands out

## Design Workflow

1. **Check for design system first**: Ask user if they have existing tokens/specs, or discover from current Penpot file
2. **Understand the page**: Call `mcp__penpot__execute_code` with `penpotUtils.shapeStructure()` to see hierarchy
3. **Find elements**: Use `penpotUtils.findShapes()` to locate elements by type or name
4. **Create/modify**: Use `penpot.createBoard()`, `penpot.createRectangle()`, `penpot.createText()` etc.
5. **Apply layout**: Use `addFlexLayout()` for responsive containers
6. **Validate**: Call `mcp__penpot__export_shape` to visually check your work

## Design System Handling

**Before creating designs, determine if the user has an existing design system:**

1. **Ask the user**: "Do you have a design system or brand guidelines to follow?"
2. **Discover from Penpot**: Check for existing components, colors, and patterns

```javascript
// Discover existing design patterns in current file
const allShapes = penpotUtils.findShapes(() => true, penpot.root);

// Find existing colors in use
const colors = new Set();
allShapes.forEach(s => {
  if (s.fills) s.fills.forEach(f => colors.add(f.fillColor));
});

// Find existing text styles (font sizes, weights)
const textStyles = allShapes
  .filter(s => s.type === 'text')
  .map(s => ({ fontSize: s.fontSize, fontWeight: s.fontWeight }));

// Find existing components
const components = penpot.library.local.components;

return { colors: [...colors], textStyles, componentCount: components.length };
```

**If user HAS a design system:**

- Use their specified colors, spacing, typography
- Match their existing component patterns
- Follow their naming conventions

**If user has NO design system:**

- Use the default tokens below as a starting point
- Offer to help establish consistent patterns
- Reference specs in [component-patterns.md](references/component-patterns.md)

## Key Penpot API Gotchas

- `width`/`height` are READ-ONLY → use `shape.resize(w, h)`
- `parentX`/`parentY` are READ-ONLY → use `penpotUtils.setParentXY(shape, x, y)`
- Use `insertChild(index, shape)` for z-ordering (not `appendChild`)
- Flex children array order is REVERSED for `dir="column"` or `dir="row"`
- After `text.resize()`, reset `growType` to `"auto-width"` or `"auto-height"`

## Positioning New Boards

**Always check existing boards before creating new ones** to avoid overlap:

```javascript
// Find all existing boards and calculate next position
const boards = penpotUtils.findShapes(s => s.type === 'board', penpot.root);
let nextX = 0;
const gap = 100; // Space between boards

if (boards.length > 0) {
  // Find rightmost board edge
  boards.forEach(b => {
    const rightEdge = b.x + b.width;
    if (rightEdge + gap > nextX) {
      nextX = rightEdge + gap;
    }
  });
}

// Create new board at calculated position
const newBoard = penpot.createBoard();
newBoard.x = nextX;
newBoard.y = 0;
newBoard.resize(375, 812);
```

**Board spacing guidelines:**

- Use 100px gap between related screens (same flow)
- Use 200px+ gap between different sections/flows
- Align boards vertically (same y) for visual organization
- Group related screens horizontally in user flow order

## Default Design Tokens

**Use these defaults only when user has no design system. Always prefer user's tokens if available.**

### Spacing Scale (8px base)

| Token | Value | Usage |
| ----- | ----- | ----- |
| `spacing-xs` | 4px | Tight inline elements |
| `spacing-sm` | 8px | Related elements |
| `spacing-md` | 16px | Default padding |
| `spacing-lg` | 24px | Section spacing |
| `spacing-xl` | 32px | Major sections |
| `spacing-2xl` | 48px | Page-level spacing |

### Typography Scale

| Level | Size | Weight | Usage |
| ----- | ---- | ------ | ----- |
| Display | 48-64px | Bold | Hero headlines |
| H1 | 32-40px | Bold | Page titles |
| H2 | 24-28px | Semibold | Section headers |
| H3 | 20-22px | Semibold | Subsections |
| Body | 16px | Regular | Main content |
| Small | 14px | Regular | Secondary text |
| Caption | 12px | Regular | Labels, hints |

### Color Usage

| Purpose | Recommendation |
| ------- | -------------- |
| Primary | Main brand color, CTAs |
| Secondary | Supporting actions |
| Success | #22C55E range (confirmations) |
| Warning | #F59E0B range (caution) |
| Error | #EF4444 range (errors) |
| Neutral | Gray scale for text/borders |

## Common Layouts

### Mobile Screen (375×812)

```text
┌──────────────