drawio-logical-diagrams

SKILL.md

Draw.io Logical Diagrams Creation

Overview

Create professional logical diagrams in draw.io's native XML format for logical flow diagrams, system architecture visualizations, and abstract process representations using generic shapes and symbols.

When to Use

Creating logical flow diagrams showing data flow between system components

Designing logical architecture diagrams (abstract system structure)

Building BPMN process diagrams for business processes

Drawing UML diagrams (class, sequence, activity, state)

Creating data flow diagrams (DFD) for system analysis

Making decision flowcharts with branching logic

Visualizing system interactions and sequences

Documenting logical system design without cloud specifics

Do NOT use for: AWS/Azure/GCP architecture diagrams (use aws-drawio-architecture-diagrams).
Instructions

Creating a Logical Diagram

Analyze the request: Understand the system/process to diagram

Choose diagram type: Flowchart, architecture, BPMN, UML, DFD, etc.

Identify elements: Determine actors, processes, data stores, connectors

Draft XML structure: Create the mxGraphModel with proper root cells

Add shapes: Create mxCell elements with appropriate styles

Add connectors: Link elements with edge elements

Validate XML: Verify XML is well-formed and all IDs are unique (see validation checklist below)

Output: Write the .drawio file for the user

XML Validation Checklist

Before outputting the file, verify:

 All tags are properly closed (no unclosed <mxCell>, </mxGeometry>, etc.)

 All cell IDs are unique (0 and 1 are reserved root cells, use sequential integers starting from 2)

 All source and target attributes reference existing cell IDs

 All parent attributes reference existing cell IDs

 All coordinates (x, y, width, height) are positive numbers

 Special characters are escaped (< → <, > → >, & → &)

 Multi-line labels use &#xa; or <br> with html=1 in style

Key XML Components

Component
Description

mxfile
Root element with host and version

diagram
Contains the diagram definition

mxGraphModel
Canvas settings (grid, page size)

root
Container for all cells (must include id="0" and id="1")

mxCell
Individual shapes (vertices) or connectors (edges)

Draw.io XML Structure

<mxfile host="app.diagrams.net" agent="Claude" version="24.7.17">
  <diagram id="logical-flow-1" name="Logical Flow">
    <mxGraphModel dx="1200" dy="800" grid="1" gridSize="10" guides="1"
      tooltips="1" connect="1" arrows="1" fold="1" page="1"
      pageScale="1" pageWidth="1169" pageHeight="827" math="0" shadow="0">
      <root>
        <mxCell id="0" />
        <mxCell id="1" parent="0" />
        <!-- Shapes and connectors here -->
      </root>
    </mxGraphModel>
  </diagram>
</mxfile>

Key rules:

IDs "0" and "1" are reserved for root cells

Use sequential integer IDs starting from "2"

Use landscape orientation for architecture diagrams

All coordinates must be positive and aligned to grid (multiples of 10)

Generic Shapes and Styles

Basic Shape Types

Shape
Style

Rectangle
rounded=0;whiteSpace=wrap;html=1;

Rounded Rectangle
rounded=1;whiteSpace=wrap;html=1;

Ellipse/Circle
ellipse;whiteSpace=wrap;html=1;

Diamond
rhombus;whiteSpace=wrap;html=1;

Cylinder
shape=cylinder3;whiteSpace=wrap;html=1;boundedLbl=1;

Hexagon
shape=hexagon;perimeter=hexagonPerimeter2;whiteSpace=wrap;html=1;

Parallelogram
shape=ext;double=1;rounded=0;whiteSpace=wrap;html=1;

Standard Color Palette

Element Type
Fill Color
Border Color
Usage

Process
#dae8fc
#6c8ebf
Operations/actions

Decision
#fff2cc
#d6b656
Conditional branches

Start/End
#d5e8d4
#82b366
Terminal states

Data/Store
#e1f5fe
#0277bd
Databases/files

Entity
#f3e5f5
#7b1fa2
External systems

Error/Stop
#f8cecc
#b85450
Error states

Actor/User
#ffe0b2
#f57c00
Users/actors

Container
#f5f5f5
#666666
Grouping areas

Connector Styles

Standard flow:

edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;endArrow=classic;endFill=1;strokeColor=#666666;strokeWidth=2;

Dashed (alternative/optional):

edgeStyle=orthogonalEdgeStyle;dashed=1;dashPattern=5 5;strokeColor=#666666;

Arrow head styles:

endArrow=classic;endFill=1 - Filled triangle

endArrow=open;endFill=0 - Open arrow

endArrow=blockThin;endFill=1 - Block arrow

Diagram Types

Type
Key Elements

Logical Flow
Actors (orange), Services (blue), Data Stores (cyan), External Systems (purple)

Logical Architecture
Layered containers with nested components

BPMN
Circle (Start/End), Rounded Rectangle (Activity), Diamond (Gateway)

UML Sequence
Vertical lifelines with message arrows

DFD
Square (Entity), Circle (Process), Open Rectangle (Data Store)

Reference Files

For detailed shape examples and style references, see:

shape-styles.md - Complete shape examples and style reference

diagram-templates.md - Ready-to-use templates

Examples

Example 1: Order Processing Flow

Request: "Create a logical flow diagram showing order processing: customer submits order, system validates, if valid then processes payment and ships, if invalid notifies customer."

<mxfile host="app.diagrams.net" agent="Claude" version="24.7.17">
  <diagram id="order-flow-1" name="Order Processing">
    <mxGraphModel dx="1200" dy="800" grid="1" gridSize="10" guides="1" tooltips="1" connect="1" arrows="1" fold="1" page="1" pageScale="1" pageWidth="1169" pageHeight="827" math="0" shadow="0">
      <root>
        <mxCell id="0"/><mxCell id="1" parent="0"/>
        <mxCell id="2" value="Start" style="ellipse;whiteSpace=wrap;html=1;fillColor=#d5e8d4;strokeColor=#82b366;fontSize=12;" vertex="1" parent="1"><mxGeometry x="80" y="50" width="80" height="40" as="geometry"/></mxCell>
        <mxCell id="3" value="Submit Order" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;fontSize=12;" vertex="1" parent="1"><mxGeometry x="60" y="130" width="120" height="60" as="geometry"/></mxCell>
        <mxCell id="4" value="Validate&#xa;Order?" style="rhombus;whiteSpace=wrap;html=1;fillColor=#fff2cc;strokeColor=#d6b656;fontSize=12;" vertex="1" parent="1"><mxGeometry x="80" y="230" width="80" height="80" as="geometry"/></mxCell>
        <mxCell id="5" value="Notify&#xa;Customer" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#f8cecc;strokeColor=#b85450;fontSize=12;" vertex="1" parent="1"><mxGeometry x="220" y="240" width="100" height="50" as="geometry"/></mxCell>
        <mxCell id="6" value="Process&#xa;Payment" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;fontSize=12;" vertex="1" parent="1"><mxGeometry x="60" y="350" width="120" height="60" as="geometry"/></mxCell>
        <mxCell id="7" value="Ship Order" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;fontSize=12;" vertex="1" parent="1"><mxGeometry x="60" y="450" width="120" height="60" as="geometry"/></mxCell>
        <mxCell id="8" value="End" style="ellipse;whiteSpace=wrap;html=1;fillColor=#d5e8d4;strokeColor=#82b366;fontSize=12;" vertex="1" parent="1"><mxGeometry x="80" y="550" width="80" height="40" as="geometry"/></mxCell>
        <mxCell id="10" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=classic;endFill=1;strokeColor=#666666;strokeWidth=2;" edge="1" parent="1" source="2" target="3"><mxGeometry relative="1" as="geometry"/></mxCell>
        <mxCell id="11" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=classic;endFill=1;strokeColor=#666666;strokeWidth=2;" edge="1" parent="1" source="3" target="4"><mxGeometry relative="1" as="geometry"/></mxCell>
        <mxCell id="12" value="No" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=classic;endFill=1;strokeColor=#b85450;strokeWidth=2;fontSize=11;" edge="1" parent="1" source="4" target="5"><mxGeometry relative="1" as="geometry"/></mxCell>
        <mxCell id="13" value="Yes" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=classic;endFill=1;strokeColor=#82b366;strokeWidth=2;fontSize=11;" edge="1" parent="1" source="4" target="6"><mxGeometry relative="1" as="geometry"/></mxCell>
        <mxCell id="14" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=classic;endFill=1;strokeColor=#666666;strokeWidth=2;" edge="1" parent="1" source="6" target="7"><mxGeometry relative="1" as="geometry"/></mxCell>
        <mxCell id="15" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=classic;endFill=1;strokeColor=#666666;strokeWidth=2;" edge="1" parent="1" source="7" target="8"><mxGeometry relative="1" as="geometry"/></mxCell>
        <mxCell id="16" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=classic;endFill=1;strokeColor=#b85450;strokeWidth=2;" edge="1" parent="1" source="5" target="8"><mxGeometry relative="1" as="geometry"/></mxCell>
      </root>
    </mxGraphModel>
  </diagram>
</mxfile>

Example 2: Three-Tier Logical Architecture

Request: "Create a logical architecture diagram for a web application with presentation, business logic, and data tiers."

<mxfile host="app.diagrams.net" agent="Claude" version="24.7.17">
  <diagram id="three-tier-1" name="Three-Tier Architecture">
    <mxGraphModel dx="1200" dy="800" grid="1" gridSize="10" guides="1" tooltips="1" connect="1" arrows="1" fold="1" page="1" pageScale="1" pageWidth="1169" pageHeight="827" math="0" shadow="0">
      <root>
        <mxCell id="0"/><mxCell id="1" parent="0"/>
        <mxCell id="2" value="User" style="ellipse;whiteSpace=wrap;html=1;fillColor=#ffe0b2;strokeColor=#f57c00;fontSize=12;" vertex="1" parent="1"><mxGeometry x="40" y="340" width="60" height="40" as="geometry"/></mxCell>
        <mxCell id="3" value="Presentation Layer" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#f5f5f5;strokeColor=#666666;fontSize=14;fontStyle=1;" vertex="1" parent="1"><mxGeometry x="160" y="40" width="300" height="180" as="geometry"/></mxCell>
        <mxCell id="4" value="Web&#xa;Browser" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;fontSize=12;" vertex="1" parent="3"><mxGeometry x="20" y="30" width="80" height="50" as="geometry"/></mxCell>
        <mxCell id="5" value="Mobile&#xa;App" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;fontSize=12;" vertex="1" parent="3"><mxGeometry x="120" y="30" width="80" height="50" as="geometry"/></mxCell>
        <mxCell id="7" value="Application Layer" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#f5f5f5;strokeColor=#666666;fontSize=14;fontStyle=1;" vertex="1" parent="1"><mxGeometry x="160" y="260" width="300" height="180" as="geometry"/></mxCell>
        <mxCell id="8" value="API&#xa;Gateway" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#fff2cc;strokeColor=#d6b656;fontSize=12;" vertex="1" parent="7"><mxGeometry x="20" y="30" width="80" height="50" as="geometry"/></mxCell>
        <mxCell id="9" value="Business&#xa;Logic" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#dae8fc;strokeColor=#6c8ebf;fontSize=12;" vertex="1" parent="7"><mxGeometry x="110" y="30" width="80" height="50" as="geometry"/></mxCell>
        <mxCell id="11" value="Data Layer" style="rounded=1;whiteSpace=wrap;html=1;fillColor=#f5f5f5;strokeColor=#666666;fontSize=14;fontStyle=1;" vertex="1" parent="1"><mxGeometry x="160" y="480" width="300" height="180" as="geometry"/></mxCell>
        <mxCell id="12" value="Primary&#xa;Database" style="shape=cylinder3;whiteSpace=wrap;html=1;boundedLbl=1;fillColor=#e1f5fe;strokeColor=#0277bd;fontSize=12;" vertex="1" parent="11"><mxGeometry x="20" y="30" width="60" height="80" as="geometry"/></mxCell>
        <mxCell id="13" value="Cache" style="shape=cylinder3;whiteSpace=wrap;html=1;boundedLbl=1;fillColor=#fff3e0;strokeColor=#e65100;fontSize=12;" vertex="1" parent="11"><mxGeometry x="100" y="30" width="60" height="80" as="geometry"/></mxCell>
        <mxCell id="20" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=classic;endFill=1;strokeColor=#666666;strokeWidth=2;" edge="1" parent="1" source="2" target="4"><mxGeometry relative="1" as="geometry"/></mxCell>
        <mxCell id="21" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=classic;endFill=1;strokeColor=#666666;strokeWidth=2;" edge="1" parent="1" source="4" target="8"><mxGeometry relative="1" as="geometry"/></mxCell>
        <mxCell id="22" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=classic;endFill=1;strokeColor=#666666;strokeWidth=2;" edge="1" parent="1" source="8" target="9"><mxGeometry relative="1" as="geometry"/></mxCell>
        <mxCell id="23" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=classic;endFill=1;strokeColor=#666666;strokeWidth=2;" edge="1" parent="1" source="9" target="12"><mxGeometry relative="1" as="geometry"/></mxCell>
        <mxCell id="24" value="query" style="edgeStyle=orthogonalEdgeStyle;rounded=0;endArrow=open;endFill=0;strokeColor=#666666;strokeWidth=1;fontSize=10;dashed=1;" edge="1" parent="1" source="9" target="13"><mxGeometry relative="1" as="geometry"/></mxCell>
      </root>
    </mxGraphModel>
  </diagram>
</mxfile>

For additional templates (microservice architecture, event-driven, decision tree, sequence, DFD), see diagram-templates.md.

Constraints and Warnings

Critical Constraints

XML validity: Always close tags properly and escape special characters

Unique IDs: All cell IDs must be unique (except parent "0" and "1")

Valid references: Source/target must reference existing cell IDs

Positive coordinates: All x, y values must be >= 0

Warnings

XML files must be well-formed or will fail to open in draw.io

Invalid parent references cause elements to disappear

Negative coordinates place elements outside visible canvas

Best Practices

Use consistent colors per element type across all diagrams

Keep arrows straight with minimal bends

Place labels at least 20px from arrow lines

Group related elements in containers

Use 12-14px font for labels, 10-11px for annotations

Align all coordinates to grid (multiples of 10)

Use high contrast colors and don't rely solely on color for meaning

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