Table of Contents

• Diagram Types
• What’s in This Section
• Diagram Type Documentation Format
• Quick Reference
• Choosing the Right Diagram Type
  • For Processes and Workflows
  • For Structure and Relationships
  • For Data Visualization
  • For Planning and Tracking
  • For Software Development
• Mermaid.js Compatibility
• Examples
• Need Help?

Diagram Types

Complete reference documentation for all 24 diagram types registered in Sirena.

What’s in This Section

Detailed syntax and examples for:

• Flowchart diagrams

• Sequence diagrams

• Class diagrams

• State diagrams

• ER diagrams

• User journey diagrams

• Git graph diagrams

• Pie charts

• Gantt charts

• Quadrant charts

• Requirement diagrams

• C4 diagrams

• Mindmaps

• Timeline diagrams

• Sankey diagrams

• XY charts

• Block diagrams

• Architecture diagrams

• Kanban boards

Plus additional specialized types:

• Radar charts

• Treemap diagrams

• Packet diagrams

• Info diagrams

• Error diagrams

Diagram Type Documentation Format

Each diagram type page includes:

• Overview - What the diagram type is for

• Use cases - When to use this type

• Syntax specification - Complete syntax reference

• Elements - Available node/element types

• Relationships - Connection and edge types

• Examples - From basic to advanced

• Features - Special capabilities

• Limitations - Current constraints

• Best practices - Recommended usage patterns

Quick Reference

Diagram Type	Primary Use Case	Keyword
Flowchart	Process flows and decision trees	graph, flowchart
Sequence	Message interactions over time	sequenceDiagram
Class	Object-oriented design	classDiagram
State	State machines	stateDiagram-v2
ER Diagram	Database design	erDiagram
User Journey	User experience flows	journey
Git Graph	Repository history	gitGraph
Pie Chart	Proportional data	pie
Gantt	Project timelines	gantt
Quadrant	Priority matrices	quadrantChart
Requirement	Requirements traceability	requirementDiagram
C4	Software architecture	C4Context, C4Container, C4Component, C4Dynamic, C4Deployment
Mindmap	Hierarchical ideas	mindmap
Timeline	Historical events	timeline
Sankey	Flow quantities	sankey-beta
XY Chart	Data plotting	xychart-beta
Block	Component relationships	block-beta
Architecture	System architecture	architecture-beta
Kanban	Workflow boards	kanban

Choosing the Right Diagram Type

For Processes and Workflows

• Flowchart - General process flows

• Sequence - Time-based interactions

• State - State transitions

• User Journey - User experience flows

For Structure and Relationships

• Class - Object relationships

• ER Diagram - Data relationships

• Block - Component relationships

• Architecture - System structure

For Data Visualization

• Pie Chart - Proportions

• XY Chart - Data points

• Sankey - Flow quantities

• Quadrant - Priority/complexity matrices

For Planning and Tracking

• Gantt - Project schedules

• Timeline - Historical events

• Kanban - Workflow status

• Requirement - Requirements traceability

For Software Development

• C4 - Architecture documentation

• Git Graph - Repository history

• Class - Code structure

• Sequence - API interactions

Mermaid.js Compatibility

No diagram type has full parity with Mermaid.js; per-type corpus pass rates are on the compatibility page. See Compatibility Guide for detailed comparison.

Examples

Find complete examples in the GitHub repository:

• Example Diagrams

Need Help?

• Check Creating Your First Diagram (planned) tutorial

• See Best Practices (planned) guide

• Visit GitHub Issues for support