Diagram Generator

Expert skill for creating clear, professional diagrams in Mermaid or ASCII format.

Supported Formats

Format	Best For	Trigger Keywords
Mermaid	Web docs, GitHub, rich rendering	"diagram", "mermaid", "visualize"
ASCII	Terminals, plain text, emails	"ASCII", "text diagram", "terminal"

Diagram Types

graph/flowchart     - Flowcharts and decision trees
sequenceDiagram     - API interactions and workflows
classDiagram        - Object-oriented structures
stateDiagram-v2     - State machines and transitions
erDiagram           - Database relationships
C4Context/C4Container/C4Component - Architecture views (C4 model)
mindmap             - Brainstorming and idea organization
block-beta          - System block diagrams
gantt               - Project timelines
pie                 - Data distributions
gitGraph            - Git branching strategies
journey             - User experience flows
quadrantChart       - Priority matrices
timeline            - Historical events

Quick Start

Determine format: Mermaid (default) or ASCII (if user explicitly requests)
Select diagram type based on what's being visualized
Choose layout: TB/TD (top-down), LR (left-right) for Mermaid
Keep readable: Max 15-20 nodes per diagram
Apply meaningful styling: Colors/shapes with semantic meaning

Output Format

Mermaid (Default)

```mermaid
graph TD
    A[Start] --> B{Decision}
    B -->|Yes| C[Action 1]
    B -->|No| D[Action 2]

    classDef success fill:#90EE90
    class C success
```

ASCII (When Explicitly Requested)

+-------+     +----------+
| Start | --> | Decision |
+-------+     +----+-----+
                   |
         +---------+---------+
         |                   |
         v                   v
    +----------+       +----------+
    | Action 1 |       | Action 2 |
    +----------+       +----------+

ASCII Conventions:

+---+ for boxes, | for vertical lines, --> or --- for connections
Use consistent spacing and alignment
Label arrows with [text] above the line when needed

Diagram Type Selection

Use Case	Recommended Type
Process/decision flow	`graph` (flowchart)
API/service interactions	`sequenceDiagram`
System architecture (high-level)	`C4Context`
System architecture (detailed)	`C4Container`, `block-beta`
Database schema	`erDiagram`
Brainstorming/ideas	`mindmap`
State transitions	`stateDiagram-v2`
Project timeline	`gantt`
Feature prioritization	`quadrantChart`

Resources

WORKFLOW.md - Detailed creation methodology
EXAMPLES.md - All diagram types with real-world examples
TROUBLESHOOTING.md - Common errors and fixes

Integration

Auto-invokes on trigger keywords (diagram, mermaid, ASCII, visualize, etc.)
Manual: Use /diagram command
With docs: Works alongside doc-coauthoring skill for documentation diagrams