Draw Mermaid Diagrams

Instructions

When the user asks to create a diagram or visualize a process, use Mermaid syntax within Markdown code blocks.

1. Identify the Diagram Type: Determine the best diagram type for the user's request (e.g., Flowchart for processes, Sequence Diagram for interactions, ER Diagram for data structures).
2. Consult the Specification: Refer to SPEC.md for syntax details if needed.
3. Generate Markdown: Output the diagram inside a mermaid code block.
4. Validate (Optional): For complex diagrams, use the validation script to check for syntax errors.

Validation

To validate a mermaid diagram file (or a markdown file containing mermaid blocks), use the validation script. It uses the official Mermaid CLI to check for syntax errors.

deno run --allow-run --allow-read --allow-write --allow-env scripts/validate.ts path/to/diagram.mmd

Diagram Types Selection

• Flowchart: Algorithms, workflows, decision trees.
• Sequence Diagram: API interactions, user flows, system communication.
• Class Diagram: Object-oriented structure, database schemas (alternative to ER).
• State Diagram: State machines, lifecycle of an object.
• ER Diagram: Database schemas, entity relationships.
• Gantt Chart: Project schedules, timelines.
• User Journey: User experience mapping.
• Pie Chart: Simple data distribution.

Examples

Flowchart Example

graph TD
    Start --> Process
    Process --> Decision{Is it valid?}
    Decision -- Yes --> End
    Decision -- No --> Error[Show Error]
    Error --> Process

Sequence Diagram Example

sequenceDiagram
    participant User
    participant System
    User->>System: Request Data
    activate System
    System-->>User: Return Data
    deactivate System

Resources

• Mermaid Specification