Draw.io Network Diagrams

Generate network diagrams using two approaches:

1. Native File Mode — Generate .drawio XML files on disk with optional PNG/SVG/PDF export via the draw.io desktop CLI (official jgraph skill-cli)
2. Browser Mode — Open diagrams in the Draw.io browser editor via the @drawio/mcp MCP server (Mermaid, XML, or CSV input)

Mode 1: Native File Generation (Official Skill-CLI)

Generate native .drawio files directly. Optionally export to PNG, SVG, or PDF with the diagram XML embedded (so the exported file remains editable in draw.io).

How to Create a Diagram

1. Generate draw.io XML in mxGraphModel format for the requested diagram
2. Write the XML to a .drawio file in the current working directory using the Write tool
3. If the user requested an export format (png, svg, pdf), export using the draw.io CLI with --embed-diagram, then delete the source .drawio file
4. Open the result — the exported file if exported, or the .drawio file otherwise

Choosing the Output Format

Check the user's request for a format preference:

• /drawio create a flowchart → flowchart.drawio
• /drawio png flowchart for login → login-flow.drawio.png
• /drawio svg: ER diagram → er-diagram.drawio.svg
• /drawio pdf architecture overview → architecture-overview.drawio.pdf

If no format is mentioned, write the .drawio file and open it. The user can ask to export later.

Supported Export Formats

| Format | Embed XML | Notes | |--------|-----------|-------| | png | Yes (-e) | Viewable everywhere, editable in draw.io | | svg | Yes (-e) | Scalable, editable in draw.io | | pdf | Yes (-e) | Printable, editable in draw.io | | jpg | No | Lossy, no embedded XML support |

PNG, SVG, and PDF all support --embed-diagram — the exported file contains the full diagram XML, so opening it in draw.io recovers the editable diagram.

draw.io CLI

The draw.io desktop app includes a command-line interface for exporting.

Locating the CLI

Try drawio first (works if on PATH), then fall back to the platform-specific path:

• macOS: /Applications/draw.io.app/Contents/MacOS/draw.io
• Linux: drawio (typically on PATH via snap/apt/flatpak)
• Windows: "C:\Program Files\draw.io\draw.io.exe"

Use which drawio (or where drawio on Windows) to check if it's on PATH before falling back.

Export Command

bash
drawio -x -f <format> -e -b 10 -o <output> <input.drawio>

Key flags:

• -x / --export: export mode
• -f / --format: output format (png, svg, pdf, jpg)
• -e / --embed-diagram: embed diagram XML in the output (PNG, SVG, PDF only)
• -o / --output: output file path
• -b / --border: border width around diagram (default: 0)
• -t / --transparent: transparent background (PNG only)
• -s / --scale: scale the diagram size
• --width / --height: fit into specified dimensions (preserves aspect ratio)
• -a / --all-pages: export all pages (PDF only)
• -p / --page-index: select a specific page (1-based)

Opening the Result

• macOS: open <file>
• Linux: xdg-open <file>
• Windows: start <file>

File Naming

• Use a descriptive filename based on the diagram content (e.g., login-flow, database-schema)
• Use lowercase with hyphens for multi-word names
• For export, use double extensions: name.drawio.png, name.drawio.svg, name.drawio.pdf — this signals the file contains embedded diagram XML
• After a successful export, delete the intermediate .drawio file — the exported file contains the full diagram

Mode 2: Browser Editor via MCP Server

Open diagrams directly in the Draw.io browser editor using the @drawio/mcp MCP server. Supports three input formats.

Mermaid Diagrams (best for quick topology graphs)

bash
python3 $MCP_CALL "npx -y @drawio/mcp" open_drawio_mermaid '{"content":"graph TD\n  A --> B"}'

XML Diagrams (best for detailed, styled diagrams with precise positioning)

bash
python3 $MCP_CALL "npx -y @drawio/mcp" open_drawio_xml '{"content":"<mxGraphModel>...</mxGraphModel>"}'

CSV Diagrams (best for device inventories)

bash
python3 $MCP_CALL "npx -y @drawio/mcp" open_drawio_csv '{"content":"## label: %name%\nname,refs\nA,B\nB,C"}'

All three tools accept optional "lightbox": true for read-only view and "dark": "auto"|"true"|"false" for dark mode.

The tool returns a Draw.io URL. Share it directly — the diagram opens in the browser editor where it can be edited, exported, or saved.

XML Format Reference

A .drawio file is native mxGraphModel XML. Always generate XML directly — Mermaid and CSV formats require server-side conversion and cannot be saved as native files.

Basic Structure

Every diagram must have this structure:

xml
<mxGraphModel>
  <root>
    <mxCell id="0"/>
    <mxCell id="1" parent="0"/>
    <!-- Diagram cells go here with parent="1" -->
  </root>
</mxGraphModel>

• Cell id="0" is the root layer
• Cell id="1" is the default parent layer
• All diagram elements use parent="1" unless using multiple layers

Common Styles

Rounded rectangle:

xml
<mxCell id="2" value="Label" style="rounded=1;whiteSpace=wrap;" vertex="1" parent="1">
  <mxGeometry x="100" y="100" width="120" height="60" as="geometry"/>
</mxCell>

Diamond (decision):

xml
<mxCell id="3" value="Condition?" style="rhombus;whiteSpace=wrap;" vertex="1" parent="1">
  <mxGeometry x="100" y="200" width="120" height="80" as="geometry"/>
</mxCell>

Arrow (edge):

xml
<mxCell id="4" value="" style="edgeStyle=orthogonalEdgeStyle;" edge="1" source="2" target="3" parent="1">
  <mxGeometry relative="1" as="geometry"/>
</mxCell>

Labeled arrow:

xml
<mxCell id="5" value="Yes" style="edgeStyle=orthogonalEdgeStyle;" edge="1" source="3" target="6" parent="1">
  <mxGeometry relative="1" as="geometry"/>
</mxCell>

Useful Style Properties

| Property | Values | Use for | |----------|--------|---------| | rounded=1 | 0 or 1 | Rounded corners | | whiteSpace=wrap | wrap | Text wrapping | | fillColor=#dae8fc | Hex color | Background color | | strokeColor=#6c8ebf | Hex color | Border color | | fontColor=#333333 | Hex color | Text color | | shape=cylinder3 | shape name | Database cylinders | | shape=mxgraph.flowchart.document | shape name | Document shapes | | ellipse | style keyword | Circles/ovals | | rhombus | style keyword | Diamonds | | edgeStyle=orthogonalEdgeStyle | style keyword | Right-angle connectors | | edgeStyle=elbowEdgeStyle | style keyword | Elbow connectors | | dashed=1 | 0 or 1 | Dashed lines | | swimlane | style keyword | Swimlane containers |

Diagram Types for Network Engineering

1. Physical Topology Diagram

Shows devices, physical links, interface names, IP addresses, and link speeds.

bash
python3 $MCP_CALL "npx -y @drawio/mcp" open_drawio_mermaid '{"content":"graph TD\n  R1[\"R1\\nCore Router\\n10.255.255.1\"]\n  R2[\"R2\\nCore Router\\n10.255.255.2\"]\n  SW1[\"SW1\\nDist Switch\\n10.255.255.3\"]\n  R1 -->|\"Gi0/0 -- Gi0/0\\n10.1.1.0/30\"| R2\n  R1 -->|\"Gi0/1 -- Gi0/1\\n10.1.2.0/30\"| SW1\n  R2 -->|\"Gi0/1 -- Gi0/1\\n10.1.3.0/30\"| SW1"}'

2. Logical Topology Diagram

Shows routing protocol relationships, areas, AS numbers, VRFs.

bash
python3 $MCP_CALL "npx -y @drawio/mcp" open_drawio_mermaid '{"content":"graph TD\n  subgraph \"OSPF Area 0\"\n    R1[\"R1 ABR\"]\n    R2[\"R2 ABR\"]\n  end\n  subgraph \"OSPF Area 1\"\n    R3[\"R3\"]\n  end\n  R1 --- R2\n  R1 --- R3"}'

3. Security Zones Diagram

Shows firewalls, DMZs, trust boundaries, ACL enforcement points.

bash
python3 $MCP_CALL "npx -y @drawio/mcp" open_drawio_mermaid '{"content":"graph LR\n  subgraph \"Untrusted\"\n    INET((Internet))\n  end\n  subgraph \"DMZ\"\n    WEB[\"Web Server\"]\n  end\n  subgraph \"Trusted\"\n    CORE[\"Core Switch\"]\n  end\n  INET --> FW[\"Firewall\"]\n  FW --> WEB\n  FW --> CORE"}'

CRITICAL: XML Well-Formedness

• NEVER use double hyphens (--) inside XML comments. -- is illegal inside <!-- --> per the XML spec and causes parse errors. Use single hyphens or rephrase.
• Escape special characters in attribute values: &, <, >, "
• Always use unique id values for each mxCell

When to Use Each Mode

| Scenario | Mode | Why | |----------|------|-----| | Generate .drawio file for version control | Native File | Produces actual file on disk | | Export PNG/SVG/PDF for documentation | Native File | CLI export with embedded XML | | Quick topology preview from discovery data | Browser | Instant visual in browser | | CSV-based inventory diagram | Browser | CSV format only available via MCP | | Mermaid syntax diagram | Browser | Mermaid conversion only via MCP | | Offline/air-gapped environment | Native File | No network needed | | Sharing a link to the diagram | Browser | Returns shareable URL |

Integration with Other Skills

• Use pyats-topology to discover the network, then generate diagrams from the data
• Use netbox-reconcile to color-code links by reconciliation status (documented/undocumented/missing)
• Use markmap-viz for hierarchical views alongside Draw.io for topology views
• Use aci-fabric-audit data to generate ACI fabric topology diagrams
• Use gait-session-tracking to record diagram generation with source data references