pencil-to-code

Pencil to Code

Export Pencil .pen designs to production React/Tailwind code.

Interface

Input:

• Frame ID to export (or entire document)
• Target framework: React (default), Vue, HTML
• Optional: Component name, output path

Output:

• React component(s) with Tailwind classes
• Tailwind theme configuration (from .pen variables)
• Optional: Screenshot comparison for validation

Workflow

1. Read Design Structure

// Get full frame tree
mcp__pencil__batch_get({
  filePath: "<path>.pen",
  nodeIds: ["frameId"],
  readDepth: 10,
  resolveInstances: true,
  resolveVariables: true
})

// Get design variables/theme
mcp__pencil__get_variables({ filePath: "<path>.pen" })

2. Extract Design Tokens

Transform .pen variables → Tailwind theme:

/* From .pen variables */
@theme {
  --color-primary: [from variables.colors.primary];
  --color-background: [from variables.colors.background];
  --font-sans: [from variables.fonts.body];
  /* ... */
}

Reference: references/token-extraction.md

3. Map Nodes to Components

.pen Node Type	React Output
frame with layout	<div className="flex ...">
frame with children	Component with children
text	<p>, <h1-6>, or <span>
ref (instance)	Reusable component
rectangle	<div> with fill
ellipse	<div className="rounded-full">
image	<img> or fill: url()

Reference: references/node-mapping.md

4. Generate Code

Component structure:

// components/[ComponentName].tsx
import { cn } from "@/lib/utils"

interface [ComponentName]Props {
  className?: string
  // Extracted props from design
}

export function [ComponentName]({ className, ...props }: [ComponentName]Props) {
  return (
    <div className={cn("[tailwind classes]", className)}>
      {/* Nested structure */}
    </div>
  )
}

Tailwind mapping:

.pen property → Tailwind class
--------------------------------
fill: #000     → bg-black
layout: horizontal → flex flex-row
gap: 16        → gap-4
padding: [16,24,16,24] → py-4 px-6
fontSize: 24   → text-2xl
fontWeight: 700 → font-bold
cornerRadius: [8,8,8,8] → rounded-lg

5. Validate (Optional)

// Screenshot the .pen frame
mcp__pencil__get_screenshot({ nodeId: "frameId" })

// Compare visually with rendered React
// (Manual step or browser automation)

6. Output

## Generated Components

### [ComponentName]
- File: `components/[ComponentName].tsx`
- Props: [list extracted props]

### Theme Configuration
- File: `app/globals.css` (additions)

## Verification
Screenshot comparison: [attached]

Translation Rules

Layout System

.pen                          Tailwind
--------------------------------------
layout: "vertical"         → flex flex-col
layout: "horizontal"       → flex flex-row
layout: "grid"             → grid
alignItems: "center"       → items-center
justifyContent: "center"   → justify-center
gap: 8                     → gap-2
gap: 16                    → gap-4
gap: 24                    → gap-6
width: "fill_container"    → w-full
height: "fill_container"   → h-full

Spacing (8-point grid)

.pen padding                  Tailwind
----------------------------------------
[8,8,8,8]                  → p-2
[16,16,16,16]              → p-4
[16,24,16,24]              → py-4 px-6
[24,32,24,32]              → py-6 px-8

Typography

.pen                          Tailwind
----------------------------------------
fontSize: 12               → text-xs
fontSize: 14               → text-sm
fontSize: 16               → text-base
fontSize: 20               → text-xl
fontSize: 24               → text-2xl
fontSize: 32               → text-3xl
fontSize: 48               → text-5xl
fontWeight: 400            → font-normal
fontWeight: 500            → font-medium
fontWeight: 600            → font-semibold
fontWeight: 700            → font-bold

Colors

.pen                          Tailwind
----------------------------------------
fill: "#FFFFFF"            → bg-white
fill: "#000000"            → bg-black
fill: variable             → bg-[var(--color-name)]
textColor: "#6B7280"       → text-gray-500
stroke: "#E5E5E5"          → border-gray-200

Border Radius

.pen cornerRadius             Tailwind
----------------------------------------
[0,0,0,0]                  → rounded-none
[4,4,4,4]                  → rounded
[8,8,8,8]                  → rounded-lg
[16,16,16,16]              → rounded-2xl
[9999,9999,9999,9999]      → rounded-full

Constraints

• Single concern: Export → code. No design modifications.
• Tailwind 4 @theme: CSS-first token system
• React + TypeScript: Default output target
• Semantic HTML: Choose appropriate elements
• Accessibility: Include aria attributes where detectable

References

• references/node-mapping.md — Complete node → component mapping
• references/token-extraction.md — Variable → theme extraction
• design-tokens/ — Token system conventions

Integration

Called by:

• design-exploration orchestrator (after direction selection)
• Direct user invocation

Composes:

• design-tokens (for theme structure)