Drawio Logical Diagrams

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

1. Analyze the request: Understand the system/process to diagram
2. Choose diagram type: Flowchart, architecture, BPMN, UML, DFD, etc.
3. Identify elements: Determine actors, processes, data stores, connectors
4. Draft XML structure: Create the mxGraphModel with proper root cells
5. Add shapes: Create mxCell elements with appropriate styles
6. Add connectors: Link elements with edge elements
7. Validate XML: Verify XML is well-formed and all IDs are unique (see validation checklist below)
8. Output: Write the .drawio file for the user

XML Validation Checklist

Before outputting the file, verify:

• [ ] All tags are properly closed (no unclosed `, `, 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 
 or ` 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

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](references/shape-styles.md) - Complete shape examples and style reference
• [diagram-templates.md](references/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."

Example 2: Three-Tier Logical Architecture

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

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

Constraints and Warnings

Critical Constraints

1. XML validity: Always close tags properly and escape special characters
2. Unique IDs: All cell IDs must be unique (except parent "0" and "1")
3. Valid references: Source/target must reference existing cell IDs
4. 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

1. Use consistent colors per element type across all diagrams
2. Keep arrows straight with minimal bends
3. Place labels at least 20px from arrow lines
4. Group related elements in containers
5. Use 12-14px font for labels, 10-11px for annotations
6. Align all coordinates to grid (multiples of 10)
7. Use high contrast colors and don't rely solely on color for meaning

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: giuseppe-trisciuoglio
• Source: giuseppe-trisciuoglio/developer-kit
• License: MIT

Install and usage instructions live in the source repository linked above.