| name | mermaidjs-v11 |
| description | Create diagrams and visualizations using Mermaid.js v11 syntax. Use when generating flowcharts, sequence diagrams, class diagrams, state diagrams, ER diagrams, Gantt charts, user journeys, timelines, architecture diagrams, or any of 24+ diagram types. Supports JavaScript API integration, CLI rendering to SVG/PNG/PDF, theming, configuration, and accessibility features. Essential for documentation, technical diagrams, project planning, system architecture, and visual communication. |
Mermaid.js v11
Overview
Create text-based diagrams using Mermaid.js v11 declarative syntax. Convert code to SVG/PNG/PDF via CLI or render in browsers/markdown files.
Quick Start
Basic Diagram Structure:
{diagram-type}
{diagram-content}
Common Diagram Types:
flowchart- Process flows, decision treessequenceDiagram- Actor interactions, API flowsclassDiagram- OOP structures, data modelsstateDiagram- State machines, workflowserDiagram- Database relationshipsgantt- Project timelinesjourney- User experience flows
See references/diagram-types.md for all 24+ types with syntax.
Creating Diagrams
Inline Markdown Code Blocks:
```mermaid
flowchart TD
A[Start] --> B{Decision}
B -->|Yes| C[Action]
B -->|No| D[End]
```
Configuration via Frontmatter:
```mermaid
---
theme: dark
---
flowchart LR
A --> B
```
Comments: Use %% prefix for single-line comments.
CLI Usage
Convert .mmd files to images:
# Installation
npm install -g @mermaid-js/mermaid-cli
# Basic conversion
mmdc -i diagram.mmd -o diagram.svg
# With theme and background
mmdc -i input.mmd -o output.png -t dark -b transparent
# Custom styling
mmdc -i diagram.mmd --cssFile style.css -o output.svg
See references/cli-usage.md for Docker, batch processing, and advanced workflows.
JavaScript Integration
HTML Embedding:
<pre class="mermaid">
flowchart TD
A[Client] --> B[Server]
</pre>
<script src="https://cdn.jsdelivr.net/npm/mermaid@latest/dist/mermaid.min.js"></script>
<script>mermaid.initialize({ startOnLoad: true });</script>
See references/integration.md for Node.js API and advanced integration patterns.
Configuration & Theming
Common Options:
theme: "default", "dark", "forest", "neutral", "base"look: "classic", "handDrawn"fontFamily: Custom font specificationsecurityLevel: "strict", "loose", "antiscript"
See references/configuration.md for complete config options, theming, and customization.
Practical Patterns
Load references/examples.md for:
- Architecture diagrams
- API documentation flows
- Database schemas
- Project timelines
- State machines
- User journey maps
Resources
references/diagram-types.md- Syntax for all 24+ diagram typesreferences/configuration.md- Config, theming, accessibilityreferences/cli-usage.md- CLI commands and workflowsreferences/integration.md- JavaScript API and embeddingreferences/examples.md- Practical patterns and use cases