シナリオ
プロダクトアーキテクトが銀行チャネルの C4 コンテキスト図を必要とし、続けて同じシステムのコンテナビューを描きたい。第二の C4 専用ツールへ書き出さずに。
C4 は Kubernetes およびクラウドパックの隣にあり、コンテキスト図とそれを実装するクラスタを同じワークスペースに置けます。モデルが変わったらスナップショットまたは JSON を書き出します。C4 パックは Free です。
描くもの
C4アーキテクチャ図
- Person と External Person
- Software System と External System
- Container と Component
- Database
- システム境界とコンテナ境界
- ビューがインフラに降りるときの Deployment node
Archboard を選ぶ理由
Archboard は C4 アーキテクチャツールであり、それ以上です。Person、Software System、Container、Component は、Kubernetes とネットワークのパックと同じホスト型キャンバスにあります。IcePanel は C4 に焦点を当てています。C4 が地図の一層なら、購読するワークスペースは Archboard です。
このキャンバスのパック
C4 · UML · フローチャート · シーケンス
すべての組み込みパックは Free で使えます（3 ダイアグラム、各ダイアグラム 15 ノード＋メモ・テキスト・ステッカー・マインドマップのトピック 150 件、ブランド付き公開共有、AI エージェントとのライブ編集）。Pro では無制限のダイアグラムとノード、チームメイトがライブ編集するためのシート、埋め込み、透かしなしの書き出しが加わります（$10/シート/月）。
セッションの流れ
無料で始め、キャンバスを開く（C4 パックは含まれます）
Person と Software System を置き、システム境界で囲む
製品を変えずに Container と Component に下りる
モデルは JSON、デザインレビューは SVG/PNG で書き出す
C4 diagrams without a second tool
C4 architecture diagrams usually force a tool switch: context views in one product, container views in another, and the Kubernetes reality nowhere near either. That split is where models rot, because the context diagram says one thing while the cluster does another. Drawing C4 on the same canvas as Kubernetes, cloud, and network packs removes the seam. Person and Software System sit at the top, Container and Component below, and the Namespace frames that implement them further down. One workspace, one visual language, one map to keep current.
Keep each C4 level on its own area of the board instead of cramming context and component into one frame. The context view answers who uses the system and which external systems it touches; the container view answers what runs where; the component view answers how a container is built. Link the levels with consistent names, such as the same API container label in the container view and beside the cluster, so reviewers can trace a request from Person to Pod without switching products.
From C4 model to engineering artifact
A C4 diagram becomes an engineering artifact when it exports like one. Snapshot a revision before architecture review, export structured JSON for the model, and hand designers an SVG or PNG for the review deck. Share a branded public link with stakeholders who will never open the editor; they can pan, zoom, and read the same board. Pro adds embed for architecture decision records plus watermark-free PDF and JPEG for the moments a snapshot must look final. Reviews go faster when the model and the picture never disagree.
The C4 pack ships on Free: Person, Software System, Container, Component, Database, and boundaries, next to UML and sequence packs when a flow needs them. Start with the context of the system you are actually changing, drill into containers in the same file, and let the canvas, not a slide deck, carry the model forward. That is what a C4 architecture tool should do: keep the model where the system lives.
Open a published example
- C4 Container ViewPerson, systems, containers, and database with boundaries.
- Auth SequenceSequence view of an OAuth-style flow between actors and services.
Questions
Is Archboard a C4 architecture tool?
Yes. The C4 pack covers Person, Software System, Container, Component, Database, and boundaries on the same infinite canvas as Kubernetes, cloud, and network packs, so you get C4 plus the rest of the map, not C4 alone.
Should context and container views share one file?
Yes. Keep them in labeled areas of one canvas with consistent names, so a request can be traced from Person to container to cluster without switching products or hunting across files. One file also means one revision history and one share link for the whole model.
Can I export the C4 model, not just the picture?
Yes. Every diagram is a structured JSON document: export it for the model, snapshot revisions before reviews, and use SVG, PNG, JPEG, or PDF when the audience needs a snapshot.