offline-diagram-triplet

name	offline-diagram-triplet
description	Create editable offline diagrams from an English description or Mermaid source. Use when Codex should emit a triplet: Mermaid source, an editable .excalidraw file for excalidraw.com, and rendered SVG/PNG assets with zero network access.

Offline Diagram Triplet

Use this skill to turn an English diagram request into four local artifacts:

1. Mermaid source (.mmd)
2. Editable Excalidraw scene (.excalidraw)
3. Rendered SVG (.svg)
4. Rendered PNG (.png)

Also create a Markdown snippet when the user wants the Mermaid source embedded in docs. Keep everything local and offline.

Workflow

1. Convert the user's English brief into a small Mermaid flowchart TD or flowchart LR.
2. Keep labels short and inspectable. Prefer 4-12 nodes.
3. Save the Mermaid source to a .mmd file.
4. Run the bundled renderer:

node plugins/codex-chef-workflows/skills/offline-diagram-triplet/scripts/render-diagram-triplet.mjs --mermaid path/to/diagram.mmd --out-dir artifacts/diagrams --name diagram-name

5. Return the created file paths and include the Mermaid block in the response or target Markdown file.

Reference Routing

Read references/diagram-contract.md before extending the renderer, handling unsupported Mermaid syntax, changing output formats, or validating Excalidraw compatibility. For ordinary small diagrams, follow the subset below.

Mermaid Subset

Use this subset for predictable offline rendering:

flowchart LR
  A[English brief] --> B[Mermaid source]
  B --> C[Editable Excalidraw]
  B --> D[SVG]
  B --> E[PNG]

Supported node forms:

• A[Rectangle]
• B(Rounded)
• C((Ellipse))
• D{Decision}
• A --> B
• A -->|edge label| B
• A -.-> B
• A ==> B
• A --- B

Avoid unsupported Mermaid features such as subgraphs, HTML labels, icons, classDefs, click handlers, remote images, and sequence diagrams unless you also implement or verify a renderer for them.

Markdown Embedding

When writing docs, embed the source:

```mermaid
flowchart LR
  A[Input] --> B[Editable diagram]
```

The starter's /make-pdf style workflows can render Markdown Mermaid blocks through their own PDF toolchain, while this skill still emits standalone local assets for review and editing.

Safety

• Do not use network services, CDN renderers, or remote Excalidraw libraries.
• Do not install packages to render diagrams.
• Do not put secrets, private paths, tokens, or credential material into diagram labels or output filenames.
• If the diagram must include private system names, keep artifacts local and do not commit them without explicit approval.