Extract Design — Dembrandt

Dembrandt runs a headless Chromium browser against any URL, walks up to thousands of DOM elements, reads computed CSS, and returns a structured design system: colors with confidence scoring, typography styles, spacing scale, border radius, borders, shadows, and interactive component styles.

How to Run

# Install once (global)
npm i -g dembrandt

# Basic extraction — outputs to terminal
dembrandt https://stripe.com

# JSON output — pipe into files or other tools
dembrandt https://stripe.com --json-only > stripe-tokens.json

# W3C DTCG format (design-tokens.org standard)
dembrandt https://stripe.com --dtcg --save-output

# Generate DESIGN.md (human + AI readable brand doc)
dembrandt https://stripe.com --design-md

# Multi-page crawl (follows internal links)
dembrandt https://stripe.com --pages 5

# Dark mode colors
dembrandt https://stripe.com --dark-mode

# Mobile viewport
dembrandt https://stripe.com --mobile

# Everything saved to output/
dembrandt https://stripe.com --save-output

Output Structure

Dembrandt returns a structured object. The key sections:

colors.palette        — Deduplicated colors with confidence (high/medium/low)
colors.semantic       — Primary, secondary color detection
colors.cssVariables   — Named CSS custom properties with LCH + OKLCH values
typography.styles     — Font family, size, weight, line-height per context
typography.sources    — Google Fonts, Adobe Fonts, variable font detection
spacing.commonValues  — Margin/padding scale with rem equivalents
spacing.scaleType     — 4px, 8px, or custom grid
borderRadius.values   — Border radius tokens with element context
borders.combinations  — Width + style + color combinations
shadows               — Box shadow elevation system
components.buttons    — Button variants with hover/active/focus states
components.inputs     — Input styles with focus states
components.links      — Link colors and hover states
components.badges     — Badge/tag/chip variants
breakpoints           — Responsive breakpoints from CSS media queries
frameworks            — Detected CSS framework (Tailwind, shadcn, MUI, etc.)
iconSystem            — Detected icon library (Heroicons, FA, Material, etc.)

Working with Extracted Tokens

Seeding a Tailwind config

After extraction, map the output to tailwind.config.js:

// tailwind.config.js
export default {
  theme: {
    colors: {
      primary: '#hex-from-colors.palette[0]',
      // ...
    },
    fontFamily: {
      sans: ['Family from typography.styles', 'system-ui'],
    },
    spacing: {
      // Map spacing.commonValues px → rem
    },
    borderRadius: {
      // Map borderRadius.values
    },
    boxShadow: {
      // Map shadows
    },
  }
}

Seeding a shadcn/ui theme

Map semantic colors to shadcn CSS variables in HSL:

:root {
  --background: /* from colors.palette — lightest neutral */;
  --foreground: /* from colors.palette — darkest neutral */;
  --primary: /* from colors.semantic.primary */;
  --primary-foreground: /* contrasting color */;
  --muted: /* mid-tone neutral */;
  --border: /* from borders.combinations[0].color */;
  --radius: /* from borderRadius.values[0].value */;
}

Reading confidence levels

Dembrandt scores every color by semantic context:

Confidence	Meaning
high	Appears on semantically labeled elements (buttons, CTAs, headers with brand classes). Almost certainly a brand color.
medium	Moderate frequency or moderate context. Likely a brand color.
low	Rare, low semantic context. May be a one-off or component-specific color.

Start with high confidence colors when building a palette. Include medium for full coverage. Treat low as reference only.

Flags Reference

Flag	What it does
--json-only	Clean JSON to stdout — pipe into files or tools
--save-output	Save JSON to output/<domain>/<timestamp>.json
--dtcg	W3C Design Tokens Community Group format
--design-md	Generate DESIGN.md — prose-first brand doc
--brand-guide	Generate a PDF brand guide
--dark-mode	Extract dark color scheme and merge into palette
--mobile	Extract at 390px mobile viewport
--pages <n>	Crawl up to N pages and merge tokens
--sitemap	Discover pages from sitemap.xml
--slow	3× timeouts — use on slow-loading or JS-heavy sites
--screenshot <path>	Save a full-page screenshot
--raw-colors	Include pre-filter raw colors in JSON output
--browser firefox	Use Firefox instead of Chromium

Anti-Bot and SPA Handling

Dembrandt handles common extraction challenges automatically:

• SPA hydration — waits 8s for React/Vue/Svelte to render before extracting
• Bot detection — spoofs hardware concurrency, device memory, removes webdriver traces
• Lazy content — scrolls the full page to trigger lazy-loaded components
• Cloudflare / bot walls — auto-retries with a visible browser if headless is blocked
• Slow sites — use --slow for 3× timeouts on heavy JS bundles

Checklist After Extraction

• Identify the 3–5 high-confidence colors — these are the core brand palette
• Check colors.semantic.primary — is it correct?
• Look at typography.styles — what are the heading and body fonts?
• Check spacing.scaleType — 4px or 8px grid?
• Review components.buttons — how many variants exist?
• Check frameworks — is Tailwind, shadcn, or MUI detected? This shapes how you apply the tokens.
• Use --dark-mode if the site has a dark theme
• Use --pages 3 if the site has a multi-section design system spread across routes