Design Skill Marketplace
Claude Code marketplace for system design using EventStorming and Mermaid diagrams.
Installation
Add this marketplace to Claude Code:
/plugin marketplace add lagz0ne/design-skill
Then install the system-design plugin:
/plugin install system-design@design-skill-marketplace
Available Plugins
System Design
Description: Transform requirements into navigable design catalogs using EventStorming methodology, Mermaid diagrams, and progressive elaboration
Categories: Architecture, Design, EventStorming, Documentation
What you get:
- EventStorming-based design process
- 5-phase progressive elaboration (Requirements → Big Picture → Processes → Data/Flows → Integration)
- Mermaid diagram templates (EventStorming, ERD, State Charts, Sequence Diagrams)
- Standardized catalog structure (
docs/design-catalog/)
- Token-efficient visual artifacts
Repository: https://github.com/lagz0ne/design-skill
Triggers: "design a system", "architect a solution", "plan a backend"
How It Works
The system-design skill guides you through 5 phases:
- Requirements - Interactive questions to understand context (no assumptions)
- Big Picture - EventStorming timeline with color-coded events/commands/actors
- Processes - Detail 2-4 critical workflows with aggregates and policies
- Data & Flows - ERD, state charts for complex entities, sequence diagrams for critical flows
- Integration - Assemble navigable catalog with all diagrams embedded
Output Structure
docs/design-catalog/
README.md # Navigation hub with all diagrams embedded
requirements.md
big-picture.mmd
processes/
process-{name}.mmd
data/
erd.mmd
state-{entity}.mmd
flows/
sequence-{flow}.mmd
All diagrams use Mermaid format and follow EventStorming color conventions.
Example: E-commerce Platform
The skill transforms a simple request into a complete design catalog:
Input: "I want to build an e-commerce platform where artisans can sell handmade products"
Output:
- 10 Mermaid diagrams (big picture, 3 processes, ERD, 2 states, 3 sequences)
- 14 hotspots identified for decisions
- Complete navigable catalog
- ~45K tokens (vs 49K baseline without skill)
See test-scenarios/ecommerce/with-skill/ for full example.
Plugin Structure
design-skill/
├── skills/
│ └── system-design/ # The skill
│ ├── SKILL.md # Main skill (470 lines)
│ └── templates/ # 7 Mermaid templates
├── .claude-plugin/
│ ├── plugin.json # Plugin metadata
│ └── marketplace.json # Marketplace catalog
├── docs/
│ └── plans/ # Design documentation
├── test-scenarios/ # TDD test cases
├── LICENSE # MIT
└── README.md # This file
Support
License
MIT License
For Developers
This skill was built using TDD for documentation:
- RED: Baseline test (49K tokens, 0 questions, ASCII diagrams)
- GREEN: Skill created (45K tokens, 6 questions, Mermaid)
- REFACTOR: Closed loopholes (explicit limits, counters)
See test-scenarios/ and docs/plans/ for full development process.
lagz0ne
lagz0ne
