vijayjoshi24 C4 Diagram
Generate interactive C4 model diagrams at the right zoom level for your audience.
Read references/notation.md before rendering any diagram.
The Four Levels
| Level | Audience | Shows |
|---|---|---|
| 1 — Context | Business, executives | The system + its users + external systems |
| 2 — Container | Architects, tech leads | Deployable units inside the system |
| 3 — Component | Engineering teams | Structural building blocks inside one container |
| 4 — Code | Developers | Class/interface level — skip unless explicitly requested |
Step 1 — Determine Level and Extract Elements
If the user hasn't specified a level, default to Context first.
Extract from the user's description:
Context: system in scope · people/actors · external systems · relationships
Container: containers (with technology) · external systems they call · relationships with protocols
Component: which container to zoom into · components (with pattern/technology) · internal + external relationships
State any assumptions you make (e.g. "Assumed: auth is delegated to the API Gateway").
Step 2 — Render the Diagram
Use the show_widget visualiser. Follow references/notation.md exactly for:
- Shapes and colours per element type
- Label format: name · [type] · description (one sentence)
- Relationship arrows: one direction, labelled with intent + technology
- Title:
{Level} Diagram — {System Name} - Legend in bottom-right corner
Make every element clickable to drill down:
- Container in Context →
sendPrompt('Draw the Container diagram for {system}') - Container in Container →
sendPrompt('Draw the Component diagram for {container}') - External system →
sendPrompt('Explain the {system} integration')
Max 10 elements per diagram. If more exist, scope to the most relevant and note omissions.
Step 3 — Quality Gate
Before delivering, verify:
- Title present
- Every element: name + [type] + description
- Every relationship: directional arrow + intent label
- External systems visually distinct (grey)
- People distinct from systems
- Legend present
- ≤10 elements
Step 4 — Offer Navigation
After Context → offer Container
After Container → offer Component for a specific container
After Component → offer Structurizr DSL export or ArchiMate equivalent
Reference Files
references/notation.md— canonical colours, shapes, label rules per level. Read before every render.references/archetypes.md— worked examples for FS, SaaS, agentic AI, microservices.