c4-diagrams
Installation
SKILL.md
C4 Diagrams
Overview
Use C4 diagrams to clarify software architecture before detailed design. Focus on boundaries, responsibilities, actors, dependencies, and data flow; draw only the levels that add value.
First Gates
Before diagramming, determine these choices. If the user already specified one, honor it. If multiple choices are ambiguous, ask one concise combined question.
| Choice | Options | Default behavior |
|---|---|---|
| Purpose | Existing code, new system, design review | Existing code requires codebase exploration first; new systems require assumptions called out. |
| Format | ASCII, Mermaid | Ask the user. Mermaid means plain Mermaid syntax, not C4-specific Mermaid. |
| Rigor | Strict C4, lightweight C4-inspired, hybrid | Ask the user. Do not decide silently. |
If the user asks to skip questions for speed, still preserve unresolved choices as explicit assumptions and keep the first diagram lightweight.