# Drawio

> Create and edit draw.io diagram files (.drawio) for architecture diagrams, flowcharts, network diagrams, and technical illustrations. Use when the user asks to create diagrams, architecture visuals, flowcharts, wireframes, network topology, or any visual that should be editable in draw.io/diagrams.net. Outputs XML-based .drawio files that can be imported directly into draw.io desktop or web app.

- Skill: `scarr05/drawio` (Agent Skill, multi-file: 5 files)
- Install (CLI): `npx skillmds@latest add scarr05/drawio`
- Raw SKILL.md: https://api.skillmd.com/api/skills/scarr05/drawio/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: scarr05 (https://skillmd.com/u/scarr05)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/scarr05/drawio

---


# Draw.io Diagram Skill

Create professional, editable diagram files in draw.io's native XML format.

## Output Format

Draw.io files are XML with this structure:

```xml
<mxfile host="app.diagrams.net" modified="DATE" agent="Claude" version="21.0.0" type="device">
  <diagram name="DIAGRAM_NAME" id="UNIQUE_ID">
    <mxGraphModel dx="1200" dy="800" grid="1" gridSize="10" guides="1" tooltips="1" connect="1" arrows="1" fold="1" page="1" pageScale="1" pageWidth="1100" pageHeight="850" math="0" shadow="0">
      <root>
        <mxCell id="0" />
        <mxCell id="1" parent="0" />
        <!-- All diagram elements go here -->
      </root>
    </mxGraphModel>
  </diagram>
</mxfile>
```

## Core Element Types

### Basic Shapes

```xml
<!-- Rectangle -->
<mxCell id="unique-id" value="Label Text" style="rounded=0;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;" vertex="1" parent="1">
  <mxGeometry x="100" y="100" width="120" height="60" as="geometry" />
</mxCell>

<!-- Rounded Rectangle -->
<mxCell id="unique-id" value="Label" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#d5e8d4;strokeColor=#82b366;" vertex="1" parent="1">
  <mxGeometry x="100" y="100" width="120" height="60" as="geometry" />
</mxCell>

<!-- Cylinder (Database) -->
<mxCell id="unique-id" value="Database" style="shape=cylinder3;whiteSpace=wrap;html=1;boundedLbl=1;backgroundOutline=1;size=15;fillColor=#f8cecc;strokeColor=#b85450;" vertex="1" parent="1">
  <mxGeometry x="100" y="100" width="80" height="80" as="geometry" />
</mxCell>

<!-- Ellipse -->
<mxCell id="unique-id" value="Node" style="ellipse;whiteSpace=wrap;html=1;fillColor=#fff2cc;strokeColor=#d6b656;" vertex="1" parent="1">
  <mxGeometry x="100" y="100" width="80" height="80" as="geometry" />
</mxCell>
```

### Containers & Groups

```xml
<!-- Swimlane (Container with Header) -->
<mxCell id="unique-id" value="Section Title" style="swimlane;fontStyle=1;align=center;verticalAlign=top;childLayout=stackLayout;horizontal=1;startSize=30;fillColor=#f5f5f5;strokeColor=#666666;fontColor=#333333;" vertex="1" parent="1">
  <mxGeometry x="40" y="40" width="200" height="150" as="geometry" />
</mxCell>

<!-- Header Bar (using brand primary color) -->
<mxCell id="unique-id" value="" style="rounded=0;whiteSpace=wrap;html=1;fillColor=#0066CC;strokeColor=#0066CC;" vertex="1" parent="1">
  <mxGeometry x="40" y="40" width="400" height="40" as="geometry" />
</mxCell>
```

### Connectors & Arrows

```xml
<!-- Basic Arrow -->
<mxCell id="unique-id" value="" style="endArrow=classic;html=1;rounded=0;strokeWidth=2;strokeColor=#666666;" edge="1" parent="1" source="source-id" target="target-id">
  <mxGeometry relative="1" as="geometry" />
</mxCell>

<!-- Bidirectional Arrow -->
<mxCell id="unique-id" value="" style="endArrow=classic;startArrow=classic;html=1;rounded=0;strokeWidth=2;" edge="1" parent="1">
  <mxGeometry relative="1" as="geometry">
    <mxPoint x="200" y="200" as="sourcePoint" />
    <mxPoint x="400" y="200" as="targetPoint" />
  </mxGeometry>
</mxCell>

<!-- Flex Arrow (Block Arrow) -->
<mxCell id="unique-id" value="" style="shape=flexArrow;endArrow=classic;html=1;fillColor=#FFB800;strokeColor=#cc9400;width=20;endSize=8;" edge="1" parent="1">
  <mxGeometry relative="1" as="geometry">
    <mxPoint x="200" y="200" as="sourcePoint" />
    <mxPoint x="400" y="200" as="targetPoint" />
  </mxGeometry>
</mxCell>

<!-- Dashed Line -->
<mxCell id="unique-id" value="" style="endArrow=classic;html=1;dashed=1;dashPattern=8 8;strokeColor=#999999;" edge="1" parent="1">
  <mxGeometry relative="1" as="geometry">
    <mxPoint x="200" y="200" as="sourcePoint" />
    <mxPoint x="400" y="200" as="targetPoint" />
  </mxGeometry>
</mxCell>
```

### Text Elements

```xml
<!-- Plain Text -->
<mxCell id="unique-id" value="Label Text" style="text;html=1;strokeColor=none;fillColor=none;align=center;verticalAlign=middle;whiteSpace=wrap;rounded=0;fontSize=12;" vertex="1" parent="1">
  <mxGeometry x="100" y="100" width="100" height="30" as="geometry" />
</mxCell>

<!-- Bold Title -->
<mxCell id="unique-id" value="Title" style="text;html=1;strokeColor=none;fillColor=none;align=center;verticalAlign=middle;whiteSpace=wrap;rounded=0;fontSize=18;fontStyle=1;fontColor=#333333;" vertex="1" parent="1">
  <mxGeometry x="100" y="20" width="300" height="40" as="geometry" />
</mxCell>

<!-- Multi-line Text (use &#xa; for newlines) -->
<mxCell id="unique-id" value="Line 1&#xa;Line 2&#xa;Line 3" style="text;html=1;strokeColor=none;fillColor=none;align=left;verticalAlign=top;whiteSpace=wrap;rounded=0;fontSize=10;" vertex="1" parent="1">
  <mxGeometry x="100" y="100" width="150" height="60" as="geometry" />
</mxCell>
```

## Common Style Properties

### Colors (use hex codes)

| Property | Purpose | Example |
|----------|---------|---------|
| `fillColor` | Background | `fillColor=#dae8fc` |
| `strokeColor` | Border | `strokeColor=#6c8ebf` |
| `fontColor` | Text | `fontColor=#333333` |

### Standard Color Palette

```
Blue:    fillColor=#dae8fc;strokeColor=#6c8ebf
Green:   fillColor=#d5e8d4;strokeColor=#82b366
Yellow:  fillColor=#fff2cc;strokeColor=#d6b656
Orange:  fillColor=#ffe6cc;strokeColor=#d79b00
Red:     fillColor=#f8cecc;strokeColor=#b85450
Purple:  fillColor=#e1d5e7;strokeColor=#9673a6
Grey:    fillColor=#f5f5f5;strokeColor=#666666
```

### Typography

| Property | Values | Example |
|----------|--------|---------|
| `fontSize` | Number | `fontSize=12` |
| `fontStyle` | 0=normal, 1=bold, 2=italic, 3=bold+italic | `fontStyle=1` |
| `align` | left, center, right | `align=center` |
| `verticalAlign` | top, middle, bottom | `verticalAlign=middle` |

### Borders & Effects

| Property | Values | Example |
|----------|--------|---------|
| `rounded` | 0 or 1 | `rounded=1` |
| `strokeWidth` | Number | `strokeWidth=2` |
| `dashed` | 0 or 1 | `dashed=1` |
| `dashPattern` | Pattern | `dashPattern=8 8` |
| `shadow` | 0 or 1 | `shadow=1` |

## Company Branding (Customisable)

This skill supports company-specific branding. Edit `references/branding.md` to set your organisation's colours and styles.

**Default brand placeholders (replace with your own):**
```
Primary:   fillColor=#0066CC;strokeColor=#0052a3;fontColor=#FFFFFF
Secondary: fillColor=#FFB800;strokeColor=#cc9400;fontColor=#333333
Dark:      fillColor=#1a1a2e;strokeColor=#1a1a2e;fontColor=#FFFFFF
Light BG:  fillColor=#f0f4f8;strokeColor=#0066CC
```

See `references/branding.md` for full customisation instructions.

## Diagram Patterns

### Architecture Diagram Layout

1. **Title bar** at top (full width, branded color)
2. **Main sections** as swimlanes or rounded containers
3. **Components** as rounded rectangles inside sections
4. **Databases** as cylinders
5. **External systems** on left/right edges
6. **Arrows** showing data/control flow
7. **Legend** in corner explaining colors/symbols
8. **Footer** with metadata

### Layered Architecture (Top to Bottom)

```
┌─────────────────────────────────────┐
│           Users / Clients           │  ← Top layer
├─────────────────────────────────────┤
│           API / Interface           │
├─────────────────────────────────────┤
│         Business Logic              │
├─────────────────────────────────────┤
│         Data / Storage              │  ← Bottom layer
└─────────────────────────────────────┘
```

### Left-to-Right Flow

```
┌──────┐     ┌──────────┐     ┌──────────┐
│Source│ ──► │ Process  │ ──► │  Target  │
└──────┘     └──────────┘     └──────────┘
```

## Best Practices

1. **Unique IDs**: Every mxCell needs a unique `id` attribute
2. **Parent hierarchy**: Set `parent="1"` for top-level elements
3. **Positioning**: Use `mxGeometry` with x, y, width, height
4. **Layering**: Elements defined later appear on top
5. **Alignment**: Use consistent x/y spacing (grid of 10-20px)
6. **Colors**: Use coordinated fill/stroke pairs from the palette
7. **Labels**: Keep text concise; use separate text elements for descriptions
8. **Whitespace**: Leave margins inside containers (20-40px padding)

## Workflow

1. Determine diagram type and layout pattern
2. Set page dimensions in `mxGraphModel` (pageWidth, pageHeight)
3. Create container structure (swimlanes, groups)
4. Add components with unique IDs
5. Add connectors referencing source/target IDs
6. Add labels and annotations
7. Add legend if using color coding
8. Save as `.drawio` file
9. Copy to `/mnt/user-data/outputs/` and present to user

## Cloud Provider Icons (AWS, Azure, GCP)

Draw.io includes built-in shape libraries for major cloud providers. Use official icons for professional architecture diagrams.

### AWS Icons (Quick Reference)

AWS uses `shape=mxgraph.aws4.resourceIcon` with `resIcon=mxgraph.aws4.SERVICE`:

```xml
<mxCell id="lambda-1" value="Lambda" style="sketch=0;outlineConnect=0;fontColor=#232F3E;fillColor=#ED7100;strokeColor=#ffffff;dashed=0;verticalLabelPosition=bottom;verticalAlign=top;align=center;html=1;fontSize=12;fontStyle=0;aspect=fixed;shape=mxgraph.aws4.resourceIcon;resIcon=mxgraph.aws4.lambda;" vertex="1" parent="1">
  <mxGeometry x="100" y="100" width="78" height="78" as="geometry" />
</mxCell>
```

**Common AWS resIcon values:**
- Compute: `ec2`, `lambda`, `ecs`, `eks`, `fargate`
- Storage: `s3`, `elastic_block_store`, `elastic_file_system`
- Database: `rds`, `dynamodb`, `aurora`, `elasticache`, `redshift`
- Networking: `vpc`, `cloudfront`, `route_53`, `api_gateway`, `elastic_load_balancing`
- Security: `iam`, `cognito`, `secrets_manager`, `kms`, `waf`

**AWS Category Colors:**
- Compute: `#ED7100`
- Storage: `#7AA116`
- Database: `#C925D1`
- Networking: `#8C4FFF`
- Security: `#DD344C`

### Azure Icons (Quick Reference)

Azure uses `image=img/lib/azure2/CATEGORY/SERVICE.svg`:

```xml
<mxCell id="vm-1" value="VM" style="aspect=fixed;html=1;points=[];align=center;image;fontSize=12;image=img/lib/azure2/compute/Virtual_Machine.svg;verticalLabelPosition=bottom;verticalAlign=top;" vertex="1" parent="1">
  <mxGeometry x="100" y="100" width="68" height="68" as="geometry" />
</mxCell>
```

**Common Azure image paths:**
- `compute/Virtual_Machine.svg`, `compute/Function_Apps.svg`
- `containers/Kubernetes_Services.svg`
- `storage/Storage_Accounts.svg`, `storage/Blob_Storage.svg`
- `databases/SQL_Database.svg`, `databases/Azure_Cosmos_DB.svg`
- `networking/Virtual_Networks.svg`, `networking/Load_Balancers.svg`
- `security/Key_Vaults.svg`, `identity/Azure_Active_Directory.svg`

### AWS Group Containers

```xml
<!-- VPC -->
<mxCell id="vpc" value="VPC" style="sketch=0;outlineConnect=0;gradientColor=none;html=1;whiteSpace=wrap;fontSize=12;fontStyle=0;shape=mxgraph.aws4.group;grIcon=mxgraph.aws4.group_vpc;strokeColor=#8C4FFF;fillColor=none;verticalAlign=top;align=left;spacingLeft=30;dashed=0;" vertex="1" parent="1">
  <mxGeometry x="40" y="40" width="400" height="300" as="geometry" />
</mxCell>

<!-- Public Subnet -->
grIcon=mxgraph.aws4.group_public_subnet;strokeColor=#7AA116;fillColor=#E9F3E6

<!-- Private Subnet -->
grIcon=mxgraph.aws4.group_private_subnet;strokeColor=#00A4A6;fillColor=#E6F6F7
```

## References

For advanced patterns and complete icon lists, see:
- `references/architecture-patterns.md` - Common architecture diagram layouts
- `references/style-guide.md` - Extended styling options and icon placement
- `references/cloud-icons.md` - Complete AWS, Azure, GCP icon reference
- `references/branding.md` - Company branding customisation guide