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
