d2listed

# D2 Diagram Standard D2 is the specialist diagram tool: use it when the repository already owns `.d2` sources, the diagram needs bespoke composition (nested containers, boards, scenarios, layers, steps), a standalone SVG, PNG, PDF, PPTX, GIF, or ASCII export is the deliverable, or Mermaid cannot express the visual cleanly. Tool choice lives in [fmind-visuals](../fmind-visuals/SKILL.md). ## Workflow 1. **State the thesis**: the visual claim, target medium, and expected reading size. 1. **Write the smallest readable source**: prefer containers, explicit directions, and short labels over manual coordinates. 1. **Choose the layout**: start with `dagre`; try `elk` only when it produces a materially clearer topology (`d2 layout` lists the engines). 1. **Apply the palette**: an Fmind article diagram imports [diagram.d2](../fmind-visuals/references/diagram.d2) and uses its classes on a light surface; elsewhere start from a built-in theme (`d2 themes`) and apply the Fmind tokens through `theme-overrides` as in [fmind-theme](../fmind-visuals/references/fmind-theme.md). 1. **Format, validate, and render**, trusting the exit status rather than the presence of an output file: ```bash d2 fmt diagram.d2 d2 validate diagram.d2 d2 diagram.d2 diagram.svg ``` 1. **Inspect the export**: clipping, crossings, font fallback, contrast, appendix behavior, and whether links or tooltips survive the target embedding. ## Gotchas - **Export format**: prefer SVG for web pages and doc