ADR 0003 — C4 as code with LikeC4
Status: Accepted
Date: 2026-09-11
Deciders: FalconX engineering
Context
MkDocs/Docusaurus/VitePress host pages but do not provide an interactive C4 model. Hand-maintained HTML/SVG maps polish well but lag service inventory.
Decision
Maintain a LikeC4 model under /c4. Engineers explore via npm run c4:dev or the exported workspace embedded in the docs site. Mermaid remains for sequence diagrams inside flow/ADR pages.
Consequences
- Topology changes update the model in git
- CI validates the model
- Learning curve for LikeC4 DSL
Alternatives considered
| Option | Why not |
|---|---|
| Structurizr DSL | Equally valid; LikeC4 chosen for lightweight local UX |
| Mermaid-only C4 | Weak for multi-view estate navigation |
| Excalidraw / draw.io only | Not reviewable as structured model |