Excalidraw Diagram Skill

Create professional diagrams in Excalidraw JSON format.

Critical: Subagent Delegation

Main agents must NEVER read .excalidraw files directly.

Excalidraw JSON is extremely verbose (4,000 – 22,000+ tokens per file). Always delegate to subagent and request text summaries, never raw JSON.

Main Agent                          Subagent
    │                                   │
    ├── Provide task description ──────►│
    │                                   ├── Read/parse files
    │                                   ├── Execute operations
    │◄── Receive text summary ──────────┤

Component Libraries

Use pre-built components from libraries/ folder first.

Library Selection

Priority Order

1. Pre-downloaded → Check libraries/ folder
2. Online → Fetch from libraries.excalidraw.com
3. Custom → Build from basic shapes (last resort)

See LIBRARIES.md for usage details.

Workflow

Create Diagram

1. Identify diagram type from user request
2. Select appropriate library and palette
3. Generate JSON with all required properties (see JSON-SCHEMA.md)
4. Verify against Quality Checklist

Modify Diagram

1. Read and parse existing file (via subagent)
2. Apply requested changes
3. Maintain style consistency
4. Return summary of changes

Defaults

Quality Checklist

Before delivering:

• Visual hierarchy clear
• Color follows 60-30-10 rule
• Text contrast ≥4.5:1 (WCAG AA)
• Elements aligned to 20px grid
• Spacing ≥40px between elements
• All connections clearly directed
• Key elements labeled
• Style consistent throughout

Reference Documentation