Adds support for Mermaid diagrams in Sphinx documentation. Create flowcharts, sequence diagrams, and other visualizations using simple text-based syntax instead of external image files.

Supported diagram types

• Flowcharts: Decision trees and process flows
• Sequence diagrams: API interactions and message flows
• Class diagrams: Object-oriented design documentation
• State diagrams: State machine representations
• Gantt charts: Project timelines and schedules
• Pie charts: Data visualization
• Git graphs: Repository branch visualization

Example usage

.. mermaid::

   graph LR
      A[Start] --> B{Decision}
      B -->|Yes| C[Process]
      B -->|No| D[End]
      C --> D

Sequence diagram:

.. mermaid::

   sequenceDiagram
      Client->>Server: Request
      Server->>Database: Query
      Database-->>Server: Result
      Server-->>Client: Response

Benefits over image files

• Version controlled as text
• Easy to edit and maintain
• Consistent styling with your theme
• No external image dependencies
• Responsive and scalable
• Can be generated automatically

Configuration

# conf.py
extensions = ['sphinxcontrib.mermaid']

# Optional: customize Mermaid settings
mermaid_version = "9.4.0"  # Specific Mermaid.js version
mermaid_init_js = "mermaid.initialize({startOnLoad:true});"

Particularly useful for API documentation, architecture guides, and process documentation where diagrams help explain complex workflows.