d2-diagramlisted

# D2 Diagram Master > Scope note: this skill is for durable, repo-committed diagram artifacts. When the > request is about an **Otto Canvas scene** (you are in a scene directory editing > `canvas.d2` / `canvas.mermaid` / `canvas.json`, or driving the Canvas HTTP API), > defer to the `otto-canvas` skill — it owns that file-backed model. The D2 syntax, > style, and quality references below still apply to Canvas D2 scenes. > Tooling: rendering needs the `d2` CLI (`brew install d2`); `scripts/d2_doctor.py` > needs python3. Both degrade gracefully when absent — validation/rendering is > skipped, never faked. Use this skill whenever the user asks to create, update, review, document, render, or reason about diagrams using D2, including architecture diagrams, sequence diagrams, ERDs, data flows, service maps, deployment diagrams, infrastructure diagrams, dependency diagrams, incident/debug diagrams, state machines, API flows, and repo-derived diagrams. This skill is optimized for agentic development environments. It should produce diagrams that are correct, readable, version-control friendly, renderable, and useful to engineers. ## Core promise Always create a durable diagram artifact, not just a sketch. The default deliverables are: 1. `docs/diagrams/<slug>.d2` — source of truth. 2. `docs/diagrams/<slug>.svg` — default rendered output when D2 is available. 3. Optional `docs/diagrams/<slug>.png` or `.pdf` when requested. 4. A short explanation of scope, assumptions, and how to