Diagram Design — Editorial Diagrams
Skill by ara.so — Design Skills collection.
Editorial-quality diagrams that match your brand. Fourteen diagram types (architecture, flowchart, sequence, state machine, ER, timeline, swimlane, quadrant, nested, tree, org chart, venn, layers, pyramid) shipped as self-contained HTML + SVG files. No build step, no shadows, no generic rounded boxes.
The skill reads your website and extracts colors + fonts, then applies them across every diagram. Your site's paper color becomes the diagram background. Your CTA color becomes the focal accent. Your body font becomes the node label family.
Installation
# Clone and symlink into Claude Code's skills directory
git clone git@github.com:cathrynlavery/diagram-design.git ~/code/diagram-design
ln -s ~/code/diagram-design/skills/diagram-design ~/.claude/skills/diagram-design
Restart Claude Code. The skill registers as diagram-design.
Alternative (plugin install):
/plugin marketplace add cathrynlavery/diagram-design
/plugin install diagram-design@diagram-design
For Codex:
npx skills add https://github.com/cathrynlavery/diagram-design --skill diagram-design
Brand Onboarding (60 seconds)
Out of the box, diagrams use a clean default palette (jet-black + atomic-tangerine). To apply your brand:
You: "onboard diagram-design to https://yoursite.com"
Claude: → fetches homepage
→ extracts dominant palette + font stack
→ maps to semantic roles (paper, ink, muted, accent)
→ shows proposed diff
→ writes to references/style-guide.md
You: "apply it"
What gets extracted:
| From your site | Becomes |
|---|---|
<body> background |
paper token |
| Primary text color | ink token |
| Secondary text | muted token |
| Cards/containers | paper-2 token |
| Brand color (CTA/link) | accent token |
<h1> font |
title font |
<body> font |
node-name font |
<code> font |
sublabel font |
Contrast checks run automatically (WCAG AA). If a color fails at diagram sizes (9–12px), the skill proposes an adjusted value.
Manual override: Edit skills/diagram-design/references/style-guide.md directly.
Creating Diagrams
Quick Start
Just ask Claude to make a diagram — it will pick the right type:
"Make an architecture diagram of my app: frontend, backend, database, Redis cache."
"I need a quadrant showing Q2 projects by impact vs effort."
"Give me a sequence diagram of the OAuth handshake."
"Create a timeline of our product milestones."
Claude will:
- Choose the appropriate diagram type
- Build the HTML + SVG
- Save it as a self-contained file
- Apply your brand tokens from
style-guide.md
The 14 Diagram Types
| Type | Use for |
|---|---|
| Architecture | Components + connections |
| Flowchart | Decision logic |
| Sequence | Messages over time |
| State machine | States + transitions |
| ER / data model | Entities + fields |
| Timeline | Events on an axis |
| Swimlane | Cross-functional flow |
| Quadrant | Two-axis positioning |
| Nested | Hierarchy by containment |
| Tree | Parent → children |
| Org chart | Ownership + routing |
| Venn | Set overlap |
| Layers | Stacked abstractions |
| Pyramid / funnel | Ranked hierarchy or drop-off |
Bonus: Consultant 2×2 (scenario matrix with named cells)
Template Scaffolds
Start from a template:
# Minimal light variant
cp assets/template.html my-diagram.html
# Full editorial with summary cards
cp assets/template-full.html my-diagram.html
Each template is self-contained HTML with inline SVG and CSS.
Working Code Examples
Example 1: Architecture Diagram
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>App Architecture</title>
<style>
:root {
--paper: #FEFEFE;
--ink: #1A1A1A;
--accent: #EB6C36;
--muted: #64748B;
--hairline: #D1D5DB;
}
body {
margin: 0;
padding: 48px;
background: var(--paper);
font-family: 'Geist', -apple-system, sans-serif;
}
svg {
display: block;
max-width: 100%;
height: auto;
}
</style>
</head>
<body>
<svg viewBox="0 0 800 600" xmlns="http://www.w3.org/2000/svg">
<!-- Frontend node (focal, coral tint) -->
<rect x="100" y="100" width="160" height="80"
fill="#FFF5F0" stroke="var(--accent)" stroke-width="2" rx="8"/>
<text x="180" y="145" text-anchor="middle"
font-size="14" font-weight="500" fill="var(--ink)">
Frontend
</text>
<!-- Backend node -->
<rect x="100" y="260" width="160" height="80"
fill="var(--paper)" stroke="var(--hairline)" stroke-width="1" rx="8"/>
<text x="180" y="305" text-anchor="middle"
font-size="14" font-weight="500" fill="var(--ink)">
Backend API
</text>
<!-- Database node -->
<rect x="400" y="260" width="160" height="80"
fill="var(--paper)" stroke="var(--hairline)" stroke-width="1" rx="8"/>
<text x="480" y="305" text-anchor="middle"
font-size="14" font-weight="500" fill="var(--ink)">
PostgreSQL
</text>
<!-- Connection lines -->
<path d="M 180 180 L 180 260" stroke="var(--muted)"
stroke-width="1" fill="none" stroke-dasharray="4 4"/>
<path d="M 260 300 L 400 300" stroke="var(--muted)"
stroke-width="1" fill="none" stroke-dasharray="4 4"/>
<!-- Labels on connections -->
<text x="190" y="220" font-size="10" fill="var(--muted)"
font-family="'Geist Mono', monospace">
HTTPS
</text>
<text x="310" y="290" font-size="10" fill="var(--muted)"
font-family="'Geist Mono', monospace">
SQL
</text>
</svg>
</body>
</html>
Example 2: Flowchart
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Decision Flow</title>
<style>
:root {
--paper: #FEFEFE;
--ink: #1A1A1A;
--accent: #EB6C36;
--muted: #64748B;
--hairline: #D1D5DB;
}
body {
margin: 0;
padding: 48px;
background: var(--paper);
font-family: 'Geist', -apple-system, sans-serif;
}
</style>
</head>
<body>
<svg viewBox="0 0 600 800" xmlns="http://www.w3.org/2000/svg">
<!-- Start node (pill shape) -->
<rect x="220" y="40" width="160" height="48"
fill="var(--ink)" rx="24"/>
<text x="300" y="68" text-anchor="middle"
font-size="12" font-weight="500" fill="var(--paper)">
Start
</text>
<!-- Decision node (diamond) -->
<path d="M 300 160 L 380 220 L 300 280 L 220 220 Z"
fill="var(--paper)" stroke="var(--hairline)" stroke-width="1"/>
<text x="300" y="225" text-anchor="middle"
font-size="12" fill="var(--ink)">
Valid user?
</text>
<!-- Process nodes -->
<rect x="420" y="196" width="140" height="48"
fill="var(--paper)" stroke="var(--hairline)" stroke-width="1" rx="8"/>
<text x="490" y="224" text-anchor="middle"
font-size="12" fill="var(--ink)">
Grant access
</text>
<rect x="40" y="196" width="140" height="48"
fill="#FFF5F0" stroke="var(--accent)" stroke-width="2" rx="8"/>
<text x="110" y="224" text-anchor="middle"
font-size="12" fill="var(--ink)">
Show error
</text>
<!-- Arrows -->
<path d="M 300 88 L 300 160" stroke="var(--muted)"
stroke-width="1" marker-end="url(#arrowhead)"/>
<path d="M 380 220 L 420 220" stroke="var(--muted)"
stroke-width="1" marker-end="url(#arrowhead)"/>
<path d="M 220 220 L 180 220" stroke="var(--accent)"
stroke-width="1" marker-end="url(#arrowhead-accent)"/>
<!-- Arrow markers -->
<defs>
<marker id="arrowhead" markerWidth="6" markerHeight="6"
refX="5" refY="3" orient="auto">
<polygon points="0 0, 6 3, 0 6" fill="var(--muted)"/>
</marker>
<marker id="arrowhead-accent" markerWidth="6" markerHeight="6"
refX="5" refY="3" orient="auto">
<polygon points="0 0, 6 3, 0 6" fill="var(--accent)"/>
</marker>
</defs>
<!-- Labels -->
<text x="390" y="210" font-size="10" fill="var(--muted)">Yes</text>
<text x="190" y="210" font-size="10" fill="var(--accent)">No</text>
</svg>
</body>
</html>
Example 3: Timeline
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Product Timeline</title>
<style>
:root {
--paper: #FEFEFE;
--ink: #1A1A1A;
--accent: #EB6C36;
--muted: #64748B;
--hairline: #D1D5DB;
}
body {
margin: 0;
padding: 48px;
background: var(--paper);
font-family: 'Geist', -apple-system, sans-serif;
}
</style>
</head>
<body>
<svg viewBox="0 0 900 300" xmlns="http://www.w3.org/2000/svg">
<!-- Timeline axis -->
<line x1="100" y1="150" x2="800" y2="150"
stroke="var(--hairline)" stroke-width="1"/>
<!-- Event 1 (focal) -->
<circle cx="200" cy="150" r="8" fill="var(--accent)"/>
<text x="200" y="120" text-anchor="middle"
font-size="12" font-weight="500" fill="var(--ink)">
Beta Launch
</text>
<text x="200" y="180" text-anchor="middle"
font-size="10" fill="var(--muted)"
font-family="'Geist Mono', monospace">
Jan 2024
</text>
<!-- Event 2 -->
<circle cx="400" cy="150" r="6" fill="var(--muted)"/>
<text x="400" y="120" text-anchor="middle"
font-size="12" fill="var(--ink)">
Feature X
</text>
<text x="400" y="180" text-anchor="middle"
font-size="10" fill="var(--muted)"
font-family="'Geist Mono', monospace">
Mar 2024
</text>
<!-- Event 3 -->
<circle cx="600" cy="150" r="6" fill="var(--muted)"/>
<text x="600" y="120" text-anchor="middle"
font-size="12" fill="var(--ink)">
Public GA
</text>
<text x="600" y="180" text-anchor="middle"
font-size="10" fill="var(--muted)"
font-family="'Geist Mono', monospace">
May 2024
</text>
</svg>
</body>
</html>
Design System Rules
Every diagram follows these constraints (enforced in all 14 type references):
Grid & Spacing
- All coordinates, widths, gaps divisible by 4 (non-negotiable)
- Base unit: 4px
- Typical node padding: 16px
- Gap between nodes: 40px minimum
- Margin from edge: 48px
Colors
- One accent color — used for 1–2 focal elements only
- Coral-tinted focal nodes:
#FFF5F0fill +accentstroke - Non-focal nodes:
paperfill +hairlinestroke - Connection lines:
muted(solid or dashed)
Typography
- Instrument Serif — titles + italic editorial callouts
- Geist Sans — node names, labels
- Geist Mono — technical sublabels (ports, URLs, field types)
- Font sizes: 10px (sublabel), 12px (label), 14px (node name), 18px (title)
Shapes
- Max border-radius: 10px (8px typical for nodes)
- Border width: 1px (hairline), 2px (focal)
- No shadows, no gradients, no blur effects
Density
- Target density: 4/10 — every node earns its place
- Show 5–9 primary nodes
- Sublabels only when they add clarity (ports, field types, conditions)
Configuration
All style tokens live in skills/diagram-design/references/style-guide.md:
| Role | Token | Light default | Dark default |
|------------|--------------|---------------|---------------|
| Background | `paper` | `#FEFEFE` | `#0F0F0F` |
| Primary | `ink` | `#1A1A1A` | `#E5E5E5` |
| Accent | `accent` | `#EB6C36` | `#F97316` |
| Muted | `muted` | `#64748B` | `#94A3B8` |
| Hairline | `hairline` | `#D1D5DB` | `#334155` |
| Card | `paper-2` | `#F8F9FA` | `#1A1A1A` |
Font stack:
| Role | Family |
|------------|---------------------------------------------|
| Title | 'Instrument Serif', Georgia, serif |
| Node name | 'Geist', -apple-system, sans-serif |
| Sublabel | 'Geist Mono', 'SF Mono', Consolas, monospace|
Edit this file to override tokens globally, or run onboard diagram-design to <url> to extract from a website.
Common Patterns
Adding Editorial Annotations
Italic callouts that sit in the margins:
"Add an annotation to this diagram explaining why Redis sits between the backend and database."
Claude will insert:
<!-- Annotation callout -->
<text x="520" y="340" font-size="11" font-style="italic"
font-family="'Instrument Serif', Georgia, serif" fill="var(--muted)">
Redis caches hot queries,
</text>
<text x="520" y="356" font-size="11" font-style="italic"
font-family="'Instrument Serif', Georgia, serif" fill="var(--muted)">
reducing DB load by 70%.
</text>
<!-- Dashed leader to relevant node -->
<path d="M 500 300 Q 510 320, 515 335" stroke="var(--muted)"
stroke-width="1" stroke-dasharray="2 3" fill="none"/>
Hand-Drawn Variant (Sketchy Filter)
"Make this diagram look hand-drawn."
Applies SVG filters for rough edges:
<defs>
<filter id="sketchy">
<feTurbulence type="fractalNoise" baseFrequency="0.05" numOctaves="2" result="noise"/>
<feDisplacementMap in="SourceGraphic" in2="noise" scale="2"/>
</filter>
</defs>
<!-- Apply to shapes -->
<rect x="100" y="100" width="160" height="80" filter="url(#sketchy)" ... />
Dark Mode Variant
All templates include CSS custom properties. To generate a dark variant:
"Create a dark mode version of this diagram."
Claude will swap tokens:
:root {
--paper: #0F0F0F;
--ink: #E5E5E5;
--accent: #F97316;
--muted: #94A3B8;
--hairline: #334155;
}
Consultant 2×2 Quadrant
Named scenario matrix (4 cells, each with a label):
"Make a 2x2 showing product strategy: differentiation vs cost, and broad vs niche market."
Generates quadrant with named cells:
<!-- Top-left cell -->
<rect x="100" y="100" width="300" height="200"
fill="#FFF5F0" stroke="var(--accent)" stroke-width="2" rx="8"/>
<text x="250" y="190" text-anchor="middle"
font-size="14" font-weight="500" fill="var(--ink)">
Premium Niche
</text>
<text x="250" y="210" text-anchor="middle"
font-size="10" fill="var(--muted)">
High margin, focused
</text>
Browsing the Gallery
Open the live gallery to see all 14 types with light/dark/editorial tabs:
open ~/.claude/skills/diagram-design/assets/index.html
Or from the repo root:
open skills/diagram-design/assets/index.html
Each example includes three variants:
- Minimal Light —
template.htmlscaffold - Minimal Dark — dark mode tokens
- Full Editorial —
template-full.htmlwith annotation callouts
Troubleshooting
"Diagram looks generic / AI-generated"
Cause: Coordinates or gaps not divisible by 4, or too many accent colors.
Fix: Check the SVG for non-4-divisible x/y/width/height. Ensure only 1–2 nodes have the accent stroke.
"Fonts not loading"
Cause: Font families require web fonts (Geist, Instrument Serif).
Fix: Add to <head>:
<link rel="preconnect" href="https://fonts.googleapis.com">
<link href="https://fonts.googleapis.com/css2?family=Instrument+Serif:ital@0;1&display=swap" rel="stylesheet">
For Geist, use the Vercel CDN or local files:
<link href="https://cdn.jsdelivr.net/npm/@vercel/style-guide@latest/fonts/geist.css" rel="stylesheet">
"Onboarding failed — no colors extracted"
Cause: Target site uses inline styles or CSS-in-JS that isn't in the DOM on initial load.
Fix: Manually set tokens in references/style-guide.md:
| Role | Token | Value |
|--------|----------|-----------|
| paper | `paper` | `#FFFFFF` |
| ink | `ink` | `#000000` |
| accent | `accent` | `#FF6B35` |
"Contrast check failed"
Cause: Extracted ink color fails WCAG AA at small sizes (9–12px).
Fix: The skill auto-adjusts and shows a proposed value. Accept it, or override in style-guide.md.
"Diagram type not recognized"
Cause: Request didn't match one of the 14 types.
Fix: Be explicit:
"Make a sequence diagram of the login flow."
"Create an architecture diagram showing microservices."
"Build a quadrant chart for prioritization."
See the selection guide in SKILL.md for triggers.
Environment Variables
If deploying diagrams to a server that applies tokens via env vars:
export DIAGRAM_PAPER="#FEFEFE"
export DIAGRAM_INK="#1A1A1A"
export DIAGRAM_ACCENT="#EB6C36"
Then reference in HTML:
<style>
:root {
--paper: ${DIAGRAM_PAPER};
--ink: ${DIAGRAM_INK};
--accent: ${DIAGRAM_ACCENT};
}
</style>
(Most users will edit style-guide.md directly instead.)
Advanced Usage
Exporting as PNG
Diagrams are self-contained HTML. To export as PNG:
# Using headless Chrome
npx playwright screenshot my-diagram.html my-diagram.png --full-page
# Or manually: open in browser, screenshot at 2x zoom for retina
Embedding in Markdown
Use an <iframe> or convert to data URI:

Or link directly:

Custom Diagram Type
To add a 15th type:
- Create
references/type-custom.mdwith the same structure as existing types - Add selection trigger to
SKILL.md:- **Custom diagram** — <use case> - Trigger: "create a custom diagram" - Drop an example in
assets/example-custom.html
Claude will auto-load the reference when triggered.
License: MIT
Repo: github.com/cathrynlavery/diagram-design
Gallery: skills/diagram-design/assets/index.html