HTML Architecture & System Diagrams

Architecture diagrams answer the questions that come up most often during incidents and design reviews: what talks to what, who owns what, where does the data live, what fails when X goes down. A good HTML system diagram is the document you open during the incident, not the one you write after.

This skill is more focused than general SVG diagrams — specifically for system-level architecture.

Pre-flight — run BEFORE writing the artifact

Invoke html-skills:html-skills-listen (Skill tool) first; it is idempotent. If it returns a URL, inject it verbatim as window.__CLAUDE_SUBMIT_URL__ in the HTML you are about to write, ?t= query string included (a local, single-session loopback handshake — not a credential). If it reported web/sandbox mode, leave that line out; submitToClaude then falls back to clipboard mode.

When to use this skill

• "Diagram our [system, architecture, services, infrastructure]"
• "Show me how X talks to Y"
• "Map our [microservices, dependencies, deployment, data flow]"
• "Document the architecture of Z for the design review"
• "Help an incident responder understand the system"